Pólipo fibroepitelial atípico em córnea de um cão Lhasa Apso / Atypical fibroepithelial polyp in the cornea of a Lhasa Apso dog

Background: Fibroepithelial polyps are benign tumors of mesenchymal and ectodermal origin. Regarding the localization related to the cutaneous region, they may affect the eyelid and periocular area. In veterinary medicine, polyps located in the urethra of dogs and monkeys, vagina of bitches and on the skin have been described. Fibroepithelial polyps may present as single to multiple nodules, exophytic to pedunculated, usually arising on a smooth surface of a common base. The aim of this paper is to describe the ocular and histopathological changes of a corneal fibroepithelial polyp of recurrent character in a dog. Case: A 20-year-old Lhasa Apso dog, with a history of progressive corneal neoformation in the right eye for 4 months. Patient was submitted to routine ophthalmic evaluation. At biomicroscopy, a discrete mucopurulent discharge was observed in the nasal corner, a nodule in the lower eyelid (± 3 mm), moderate conjunctival hyperemia, vascularization and corneal edema between 12 and 5 h, presence of a pinkish proliferative mass in 3 h, affecting the anterior stroma and opacity of the lens, Schirmer's Tear Test (STT) 20 mm/min and intraocular pressure (IOP) 10 mm/Hg. In the left eye, the STT and IOP were within normal range (17 mm/min and 11 mg/Hg, respectively) and at biomicroscopy only lens opacity was observed. Given the presence of the neoformation in the cornea, the patient underwent lamellar keratectomy to excise the mass and third eyelid flap. The tissue was then submitted to histopathology. The histopathological examination showed a proliferation of fibrous component with areas presenting reactive fibroblasts, with acidophilic cytoplasm and with little volume and slight neovascularization, presence of hyperplasia of the lining epithelium and cells with round to oval nuclei, with inconspicuous nucleoli, compatible with fibroepithelial polyp, without evidence of malignancy. After 18 months, the patient presented recurrence of the condition with a history of slow evolution (about ten months). The ophthalmic evaluation showed lesions very similar to the initial one, describing a recurrence of the lesion. Discussion: Corneal neoplasms are uncommon in dogs. The clinical findings in patients with ocular neoplasms include irregular to nodular masses, gray to reddish in color, and typically associated with a vascular supply. These features are related to the type of tumor and its degree of evolution. There are reports in the literature of ocular neoplasms such as squamous cell carcinoma, papilloma, melanocytoma, fibrosarcoma, hemangiosarcoma, melanoma, lymphoma. Related to fibroepithelial polyp with ocular involvement, there are rare reports in human literature and none in veterinary medicine. There is a human description of the presence of a polyp affecting the cornea associated with a corneal dermoid and e other cases of polyps of conjunctival origin. As far as treatment is concerned, the polyp should be surgically removed because of the possibility of recurrence, tissue metaplasia, or even transformation into a malignant tumor, as seen in the case reported here, in which even with surgical removal there was recurrence and metaplasia of the cells. Based on the histopathological findings, it can be concluded that this is a fibroepithelial polyp with a recidivating characteristic, not well described in the veterinary literature, with an atypical presentation affecting the cornea.

Treatment of limbal melanocytoma with full excision and a fresh homologous corneoscleral graft in a dog

Background: Limbal melanoma has been diagnosed in dogs and due to progression may cause vision loss and eyeballremoval. Definitive diagnosis is made through histopathological examination. Therapeutic options include full thicknessresection and repair by homologous corneal tissue, synthetic graft material, and enucleation. In this report, we describe acase of limbal melanocitoma in a dog that has been treated successfully with fresh homologous corneoscleral graft.Case: A 5-year-old female Labrador was referred to the Ophthalmology Veterinary Section of the Federal University ofRio Grande do Sul (UFRGS), Porto Alegre, Brazil, with a history of a pigmented mass located on the left eye. Ophthalmicexamination revealed a pigmented mass located at the left temporal limbus with corneal involvement. Surgical excisionfollowed by reconstruction using fresh homologous corneoscleral was recommended. The patient was premedicated withacepromazine (0.05 mg/kg, IM) and meperidine (20 mg/kg, IM). Anaesthesia was induced with propofol (10 mg/kg, IV)and maintained with isoflurane. Atracurium (0.2 mg/kg, IV) was administered to maintain a central eye position. The massand a free margin were removed by full-thickness corneoscleral resection. A corneoscleral graft was harvested from a dogthat had been euthanised for reasons unrelated to this study and sutured with 9-0 polyglactin 910 using a simple interruptedpattern. The mass was immediately fixed in 10% neutral buffered formalin and submitted for histological sectioning androutine staining. Based on the histopathological analysis it was confirmed limbal melanocytoma. Postoperative treatmentconsisted...

Treatment of limbal melanocytoma with full excision and a fresh homologous corneoscleral graft in a dog

Background: Limbal melanoma has been diagnosed in dogs and due to progression may cause vision loss and eyeballremoval. Definitive diagnosis is made through histopathological examination. Therapeutic options include full thicknessresection and repair by homologous corneal tissue, synthetic graft material, and enucleation. In this report, we describe acase of limbal melanocitoma in a dog that has been treated successfully with fresh homologous corneoscleral graft.Case: A 5-year-old female Labrador was referred to the Ophthalmology Veterinary Section of the Federal University ofRio Grande do Sul (UFRGS), Porto Alegre, Brazil, with a history of a pigmented mass located on the left eye. Ophthalmicexamination revealed a pigmented mass located at the left temporal limbus with corneal involvement. Surgical excisionfollowed by reconstruction using fresh homologous corneoscleral was recommended. The patient was premedicated withacepromazine (0.05 mg/kg, IM) and meperidine (20 mg/kg, IM). Anaesthesia was induced with propofol (10 mg/kg, IV)and maintained with isoflurane. Atracurium (0.2 mg/kg, IV) was administered to maintain a central eye position. The massand a free margin were removed by full-thickness corneoscleral resection. A corneoscleral graft was harvested from a dogthat had been euthanised for reasons unrelated to this study and sutured with 9-0 polyglactin 910 using a simple interruptedpattern. The mass was immediately fixed in 10% neutral buffered formalin and submitted for histological sectioning androutine staining. Based on the histopathological analysis it was confirmed limbal melanocytoma. Postoperative treatmentconsisted...(AU)

Melanocitoma-acantoma em um cão / Melanocytoma-acanthoma in a dog

Background: Melanocytic neoplasms are skin tumors that often occur in dogs. However, melanocytoma-acanthoma, alsocalled melanoacanthoma, is a benign melanocytic neoplasm rarely reported in this species, which has been described onlythree times in the veterinary literature. Briefly, this tumor is characterized by a single, painless, darkly pigmented and firmcutaneous papule or nodule. Histologically, it is composed of mixed populations of well-differentiated melanocytes andkeratinocytes, unlike traditional melanocytic tumors (melanoma and melanocytoma). These cells are arranged in lobulessurrounded by collagenous stroma. Melanocytes are large epithelioid cells containing varying amounts of melanin. Keratinocytes form anastomosing trabeculae with peripheral palisading, and small cysts containing amorphous or laminatedkeratin. The definitive diagnosis of melanocytoma-acanthoma is based on histopathological findings. This report describesa case of melanocytoma-acanthoma in a dog in Brazil.Case: A 9-year-old female miniature Schnauzer dog was examined at the Veterinary Hospital of the Federal Universityof Santa Maria, where a single, firm, pigmented papule was found in the auricle. The lesion had started 15 days earlier.Hematological tests and serum biochemistry profile were normal. An excisional biopsy of the papule was surgically removed and subjected to histopathological examination. The tissue was fixed in 10% neutral buffered formalin, processedroutinely and embedded in paraffin wax. Sections were stained with hematoxylin and eosin (HE). A histopathologicalexamination revealed a nonencapsulated, well-defined, extensive, densely cellular proliferation located in dermis. Thisproliferation was composed of lobules and nests of well-differentiated stratified squamous epithelium closely associatedwith neoplastic melanocytes, surrounded by thin bundles of fibrous stroma. A diagnosis of...

Melanocitoma-acantoma em um cão / Melanocytoma-acanthoma in a dog

Background: Melanocytic neoplasms are skin tumors that often occur in dogs. However, melanocytoma-acanthoma, alsocalled melanoacanthoma, is a benign melanocytic neoplasm rarely reported in this species, which has been described onlythree times in the veterinary literature. Briefly, this tumor is characterized by a single, painless, darkly pigmented and firmcutaneous papule or nodule. Histologically, it is composed of mixed populations of well-differentiated melanocytes andkeratinocytes, unlike traditional melanocytic tumors (melanoma and melanocytoma). These cells are arranged in lobulessurrounded by collagenous stroma. Melanocytes are large epithelioid cells containing varying amounts of melanin. Keratinocytes form anastomosing trabeculae with peripheral palisading, and small cysts containing amorphous or laminatedkeratin. The definitive diagnosis of melanocytoma-acanthoma is based on histopathological findings. This report describesa case of melanocytoma-acanthoma in a dog in Brazil.Case: A 9-year-old female miniature Schnauzer dog was examined at the Veterinary Hospital of the Federal Universityof Santa Maria, where a single, firm, pigmented papule was found in the auricle. The lesion had started 15 days earlier.Hematological tests and serum biochemistry profile were normal. An excisional biopsy of the papule was surgically removed and subjected to histopathological examination. The tissue was fixed in 10% neutral buffered formalin, processedroutinely and embedded in paraffin wax. Sections were stained with hematoxylin and eosin (HE). A histopathologicalexamination revealed a nonencapsulated, well-defined, extensive, densely cellular proliferation located in dermis. Thisproliferation was composed of lobules and nests of well-differentiated stratified squamous epithelium closely associatedwith neoplastic melanocytes, surrounded by thin bundles of fibrous stroma. A diagnosis of...(AU)

Melanocitoma perivulvar congénito en bovino / Perivulvar bovine congenital melanocytoma / Melanocitoma perivulvar congênito em bovino

El objetivo de este relato es describir lós hallazgos clínico, histológico de um tratamiento quirúrgico de un caso diagnosticado como melanocitoma congênito. Localizado en región perivulvar en una vaca mestiza (cebuina). Neoplasia considerada rara en especie bovina, classificación histológica variable y comportamiento biológico difícil de ser previsto.(AU)

The objective of this report is to describe the clinical, histological and surgical treatment of a case diagnosed as congenital melanocytoma, located in perivulvar region in a half-breed cow (zebu). This neoplasia is considered rare in cattle, of variable histological classification and hard to predict biological behavior.(AU)

O objetivo deste relato é descrever os achados clínicos, histológicos e o tratamento cirúrgico de um caso de melanocitoma congênita. Esta neoplasia é considerada rara na espécie bovina, de classificação histológica variável e comportamento biológico difícil de ser previsto.(AU)

Melanocitoma perivulvar congénito en bovino / Perivulvar bovine congenital melanocytoma / Melanocitoma perivulvar congênito em bovino

El objetivo de este relato es describir lós hallazgos clínico, histológico de um tratamiento quirúrgico de un caso diagnosticado como melanocitoma congênito. Localizado en región perivulvar en una vaca mestiza (cebuina). Neoplasia considerada rara en especie bovina, classificación histológica variable y comportamiento biológico difícil de ser previsto.

The objective of this report is to describe the clinical, histological and surgical treatment of a case diagnosed as congenital melanocytoma, located in perivulvar region in a half-breed cow (zebu). This neoplasia is considered rare in cattle, of variable histological classification and hard to predict biological behavior.

O objetivo deste relato é descrever os achados clínicos, histológicos e o tratamento cirúrgico de um caso de melanocitoma congênita. Esta neoplasia é considerada rara na espécie bovina, de classificação histológica variável e comportamento biológico difícil de ser previsto.

ASPECTOS ANÁTOMO-PATOLÓGICOS E AVALIAÇÃO DA FRAÇÃO DE CRESCIMENTO (KI-67) DAS NEOPLASIAS MELANOCÍTICAS DIAGNOSTICADAS EM CÃES NO SETOR DE ANATOMIA PATOLÓGICA DA UFRRJ (1999-2020).

As neoplasias melanocíticas originam-se da proliferação de melanoblastos e melanócitos e são nomeadas melanomas, quando malignas e melanocitomas, quando benignas. Os melanomas correspondem a 7% das neoplasias malignas em cães, o que torna essencial estudo acerca destes tumores. Uma vez que expressam comportamento agressivo e histologia variável, exames complementares são necessários para o estabelecimento do diagnóstico e prognóstico. A atividade mitótica pode ser um importante critério de valor prognóstico para os melanomas, pois estima a taxa de proliferação celular. Desta forma, os objetivos deste trabalho foram realizar um estudo dos tumores melanocíticos diagnosticados em cães no Setor de Anatomia Patológica (SAP) entre janeiro de 1999 a agosto de 2020, avaliar a fração de crescimento dessas neoplasias determinado pelo Ki-67 (MIB-1) e correlacioná-lo com a localização e critérios histológicos associados à gravidade. Além disso, objetivou-se estabelecer um método de contagem único e amplo para todos os tipos da neoplasia e suas localizações mais comuns. Foram avaliados os históricos, laudos de necropsias e biópsias e reavaliadas as lâminas coradas com hematoxilina e eosina (HE). Todos os dados, incluindo os epidemiológicos, foram compilados. Os melanomas amelanóticos foram submetidos ao exame imunohistoquímico com anticorpo Melan-A. Em seguida, realizou-se imuno-histoquímica com Ki- 67 e as lâminas foram contracoradas com Giemsa. Calculou-se a fração de crescimento do Ki- 67 ao contar as células em 10 campos aleatórios de cada lâmina em objetivas de 40x. Do total de 78 casos de neoplasias melanocíticas do SAP, 32 localizavam-se em cavidade oral, 29 em pele, nove em leito ungueal e as demais em locais variados, totalizando 41 fêmeas e 37 machos. Os cães SRD (29) foram os mais acometidos. A idade foi informada em 70 fichas e variou de três a 19 anos. Em 48 casos foi possível analisar as características histopatológicas. Com relação ao aspecto morfológico, os tumores foram classificados em fusiforme (um caso), epitelióide (11 casos) ou misto (35 casos). O pleomorfismo foi acentuado em 36,9% das neoplasias e a média das mitoses, de todos os campos, foi de 10,5. Em 36/78 casos (33 melanomas e três melanocitomas) foi realizada a técnica imuno-histoquímica para Ki-67. Destes, 12 apresentaram resultado positivo: três melanomas amelanóticos, oito melanomas melanóticos e um melanocitoma. Após análise estatística, verificou-se que o resultado corroborou com a literatura, visto que a variante maligna apresentou maior fração de crescimento celular, maior índice mitótico que a variante benigna, além das demais alterações histológicas observadas. Sabe-se que, quando o valor da fração de crescimento do tumor encontra-se 15%, indica prognóstico desfavorável e está relacionado com índice mitótico 3 em 10 campos na objetiva de 40x. Em quatro casos de melanomas, a fração de crescimento corresponderam a 15,28%, 15,87%, 19,13%, e 51,3% e os índices mitóticos resultaram 5, 30, 60 e 70. Conclui-se que neoplasias melanocíticas são distribuídas igualmente em ambos os gêneros, acometem predominantemente cães a partir de três anos de idade e o local mais frequente da lesão é a cavidade oral, seguido por pele e leito ungueal. No que diz respeito às neoplasias melanocíticas diagnosticadas nos últimos 22 anos no Setor de Anatomia Patológica da Universidade Federal Rural do Rio de Janeiro, pôde-se observar que os aspectos epidemiológicos relacionados ao sexo, idade, raça e localização corroboram com aqueles descritos na literatura, assim como os sítios de metástase. O melanoma melanótico foiiii observado com mais frequência, semelhante ao relatada na literatura mundial. A morfologia celular mais observada no presente estudo foi do tipo misto, diferentemente da maioria dos relatos, onde a mais frequente é a forma epitelióide. A fração de crescimento determinada pela contagem de mitoses e imunorreatividade ao Ki-67 variou significativamente entre tumores melanocíticos localizados na cavidade oral e pele. Na variante benigna, o índice proliferativo foi menor quando comparado com as neoplasias malignas e o método de contagem utilizado neste trabalho mostrou-se efetivo para todos os tipos de neoplasias melanocíticas estudadas independente da localização.

Melanocytic neoplasms originate from the proliferation of melanoblasts and melanocytes and are named melanomas when malignant and melanocytomas when benign. Melanomas account for 7% of malignant neoplasms in dogs, which makes it essential to study these tumors. Since they express aggressive behavior and variable histology, complementary tests are necessary for the establishment of diagnosis and prognosis. Mitotic activity may be an important criterion of prognostic value for melanomas, since it estimates the cell proliferation rate. Thus, the objectives of this work were to perform a study of melanocytic tumors diagnosed in dogs in the Sector of Pathological Anatomy (SAP) between January 1999 and August 2020, evaluate the growth fraction of these neoplasms determined by Ki-67 (MIB-1) and correlate it with the location and histological criteria associated with severity. In addition, we aimed to establish a single, comprehensive counting method for all types of the neoplasm and its most common locations. Histories, necropsy and biopsy reports were evaluated, and slides stained with hematoxylin and eosin (HE) were reevaluated. All data, including epidemiological data, were compiled. Amelanotic melanomas were subjected to immunohistochemical examination with Melan-A antibody. Then immunohistochemistry with Ki-67 was performed and the slides were counterstained with Giemsa. The growth fraction Ki-67 was calculated by counting the cells in 10 random fields of each slide under 40x objectives. Of the total 78 cases of SAP melanocytic neoplasms, 32 were located in the oral cavity, 29 in the skin, nine in the nail bed, and the rest in varied sites, totaling 41 females and 37 males. SRD dogs (29) were the most affected. The age was reported in 70 files and ranged from three to 19 years. In 48 cases it was possible to analyze the histopathological characteristics. Regarding the morphological aspect, the tumors were classified as fusiform (one case), epithelioid (11 cases) or mixed (35 cases). Pleomorphism was marked in 36.9% of the neoplasms and the mean number of mitoses, of all fields, was 10.5. In 36/78 cases (33 melanomas and three melanocytomas) the immunohistochemical technique for Ki-67 was performed. Of these, 12 were positive: three amelanotic melanomas, eight melanotic melanomas and one melanocytoma. When considering the Ki-67 growth fraction obtained and correlating the mitoses with the histological diagnosis, the result corroborated the literature, since the malignant variant presented more pronounced parameters than the benign variant. It is known that when the cell growth fraction value is 15%, it indicates unfavorable prognosis and is related to mitotic index 3 in 10 fields at 40x objective. In four melanoma cases, the proliferation indices corresponded to 15.28%, 15.87%, 19.13%, and 51.3% and the mitotic indices resulted 5, 30, 60, and 70. We conclude that melanocytic neoplasms are equally distributed in both genders, predominantly affect dogs over three years of age, and the most frequent site of the lesion is the oral cavity, followed by the skin and the nail bed. Regarding melanocytic neoplasms diagnosed in the last 22 years in the Pathology Sector of the Universidade Federal Rural do Rio de Janeiro, it could be observed that the epidemiological aspects related to sex, age, breed and location corroborate those described in the literature, as well as the metastasis sites. Melanotic melanoma was observed more frequently, similar to that reported in the world literature. The cell morphology most commonly observed in the present study was the mixed type, unlike most reports, where the epithelioid form is most frequent. The growth fraction determined by mitosis count and Ki-67 immunoreactivityv varied significantly between melanocytic tumors located in the oral cavity and skin. In the benign variant, the proliferative index was lower when compared to malignant neoplasms and the counting method used in this study proved to be effective for all types of melanocytic neoplasms studied regardless of location.

NEOPLASIAS MELANOCÍTICAS UVEAIS EM CÃES E GATOS: ASPECTOS MORFOLÓGICOS E IMUNO-HISTOQUÍMICOS

As lesões mais frequentes envolvendo o bulbo ocular são de natureza neoplásica e as melanocíticas são as mais comuns na úvea dos cães e na íris dos gatos. Podem ser classificadas como melanocitomas (benignas) e melanomas (malignas). Para melhor compreensão do comportamento biológico de neoplasias melanocíticas uveais em cães e gatos, foram utilizadas ferramentas histológicas e imuno-histoquímicas em 32 bulbos oculares, 27 de cães e cinco de gatos. As neoplasias dos bulbos oculares destes animais foram classificadas em benignas (19/27 - cães) ou malignas (8/27 - cães; 5/5 - gatos), e a localização das estruturas oculares envolvidas foi descrita. Determinaram-se, também, os tipos celulares destas neoplasias, os quais foram denominados como epitelioides, fusiformes e mistas, bem como tipos especiais, como de células balonosas, células gigantes multinucleadas e células em anel de sinete. Além disso, foram caracterizadas porcentagem de células com melanina, intensidade de melanina nas células, anisocitose e anisocariose, índice mitótico, presença de inflamação e necrose intratumoral, invasão vascular e desenvolvimento de glaucoma secundário à neoplasia. Para a confirmação da origem melanocítica, foi realizada imuno-histoquímica com os anticorpos anti-PNL2 (29/32) e anti-melan-A (3/3). O índice proliferativo foi verificado, utilizando-se o anticorpo anti-Ki-67, que variou de 2,8 a 12% em melanocitomas de cães, com média de 6,45 ± 4,1 e de 15,8 a 70% em melanomas de cães, com média de 38,3 ± 25,21. Os melanomas em gatos tiveram variação do índice proliferativo de 10,8 a 30,4%, com média de 18,96 ± 7,36. Também foi avaliado o índice apoptótico, utilizando o anticorpo anticaspase-3, que variou de 3,8 a 50% em melanocitomas de cães, com média de 16,62 ± 13,26 e de 30 a 84% em melanomas de cães, com média de 58,04 ± 24,25. Nos gatos, o índice apoptótico variou de 3,6 a 92%, com média de 23,16 ± 38,62. A proteína BAP1, cujo padrão de marcação poderia refletir a agressividade tumoral, similar ao relatado para neoplasias oculares melanocíticas em seres humanos, foi também avaliada, e todas as neoplasias uveais do presente estudo foram imunomarcadas. As características histológicas e imuno-histoquímicas encontradas nas neoplasias melanocíticas uveais em cães e gatos deste estudo ampliaram o conhecimento sobre o uso destas ferramentas como fatores prognósticos; entretanto, recomenda-se mais estudos com acompanhamento da sobrevida do animal após o diagnóstico

The most frequent lesions involving the eye are of neoplastic nature and melanocytic lesions are the most common in the uvea of dogs and in the iris of cats. They can be classified as melanocytomas (benign) and melanomas (malignant). For a better understanding of the biological behavior of uveal melanocytic neoplasms in dogs and cats, histological and immunohistochemical tools were applied to 32 eyes, 27 from dogs and five from cats. The ocular neoplasms of these animals were classified as benign (19/27 - dogs) or malignant (8/27 - dogs; 5/5 - cats), and the location of the involved ocular structures was described. The cell types of these neoplasms were also determined, including epithelioid, spindle and mixed, as well as special types, such as balloon cells, multinucleated giant cells and signet rings cells. In addition, the percentage of cells with melanin, the intensity of melanin within the cells, anisocytosis and anisokaryosis, the mitotic index, the presence of intratumoral inflammation and necrosis, vascular invasion and the development of secondary glaucoma were determined. To confirm the melanocytic origin, immunohistochemistry was performed with anti-PNL2 (29/32) and anti-melan-A (3/3) antibodies. The proliferative index in dogs was verified using the antiKi-67 antibody, which varied from 2.8 to 12% in melanocytomas, with an average of 6.45 ± 4.1 and from 15.8 to 70% in melanomas, with an average of 38.3 ± 25.21. The proliferative index for cats varied from 10.8 to 30.4%, with an average of 18.96 ± 7.36. The apoptotic index was also evaluated for both species, using the anti-caspase-3 antibody. For dogs, the apoptotic index varied from 3.8 to 50% in melanocytomas, with an average of 16.62 ± 13.26 and from 30 to 84% in melanomas, with an average of 58.04 ± 24.25. For cats, the apoptotic index ranged from 3.6 to 92%, with an average of 23.16 ± 38.62. The BAP1 protein, the marking pattern of which might influence tumor aggressiveness as reported for melanocytic ocular neoplasms in humans, was also evaluated in all uveal neoplasms in the present study. The histological and immunohistochemical characteristics found in uveal melanocytic neoplasms in dogs and cats in this study expanded the knowledge about the use of these tools as prognostic factors; however, further studies with animal survival follow-up after diagnosis are recommended

Estudo retrospectivo de neoplasias melanocíticas cutâneas espontâneas em cães: Caracterização histopatológica, morfométrica e sequenciamento de TP53

Cães são susceptíveis à tumores melanocíticos e a sobrevida de cães com melanoma geralmente é pequena devido ao prognóstico desfavorável. Pesquisas que auxiliem no discernimento do comportamento biológico e fatores prognósticos desta neoplasia na espécie canina permitirão estabelecer um diagnóstico e prognóstico mais precisos. Neste trabalho foram realizados dois experimentos. O primeiro teve como objetivo a caracterização histopatológica e morfométrica de neoplasias melanocíticas cutâneas espontâneas em caninos. O segundo objetivou o sequenciamento do gene tp53 em 25 neoplasias melanocíticas. Em ambos experimentos, os casos foram resgatados do arquivo de biopsias do laboratório de histopatologia da Universidade Federal de Viçosa e do laboratório PROVET. No experimento I, de cada caso, registrou-se raça, sexo, idade, tamanho e localização das lesões. Os casos foram avaliados por dois patologistas em lâminas histológicas coradas com hematoxilina e eosina e/ou despigmentadas para comprobação do diagnóstico e caracterização histopatológica: pigmentação, presença ou ausência do infiltrado pagetoide, atividade juncional e ulceração. O índice mitótico foi determinado e registrado para cada tumor. Determinou-se a proporção celular e tipo celular, infiltrado linfocitário, vasos sanguíneos e necrose. O pleomorfismo nuclear foi avaliado em uma escala de 1 a 3, por 3 patologistas distintos, os quais não compartilharam entre si seus diagnósticos e as interpretações, sendo os casos classificados mediante uma concordância dos três diagnósticos. A área e diâmetros dos núcleos de células epitelioides, fusiformes e eritrócitos foram mesurados. No experimento II, 25 neoplasias melanocíticas cutâneas caninas, fixadas em formol tamponado e embebidos em parafina, foram utilizadas para detecção de mutações do gene tp53 nos exons 5 ao 8. No experimento I, os melanomas apresentam maior tamanho quando comparados aos melanocitomas. Microscopicamente, os melanocitomas foram mais pigmentados quando comparados aos melanomas. A presença de infiltrado pagetoide esteve ausente na maioria tumores melanocíticos estudados e a atividade juncional foi observada nos melanomas e melanocitomas com frequências similares. A ulceração esteve ausente na maioria dos melanocitomas mas foi frequente nos melanomas. A maioria das lesões melanocíticas apresentaram 3 subtipos celulares: redondas, epitelioides e fusiformes. Com relação à atipia/pleomorfismo, os melanocitomas apresentaram grau discreto, enquanto os melanomas mostraram graus variando de discreto a intenso, com aumento gradual do índice mitótico à medida que o pleomorfismo aumento. Além disso, houve diferença significativa para o tamanho nuclear entre os graus de atipia/pleomorfismo dos tumores estudados. O infiltrado linfocitário foi observado com maior intensidade nos melanomas, principalmente nos melanomas classificados no grau 2. A proporção de necrose não diferiu entre melanocitomas e melanomas, porém quando considerado o grau de atipia/pleomorfismo os melanomas de grau 3 apresentaram maior porcentagem. No experimento II, todas as neoplasias melanocíticas apresentaram inserção de três bases (TAC) no éxon 5, e mutações em íntrons. Em conclusão, a avaliação da atipia/pleomorfismo em células epitelioides é um procedimento eficiente, visto que estas células representam uma grande proporção nos tumores melanocíticos e são mais fácies de avaliar que os núcleos das células fusiformes. A escala de atipia/pleomorfismo é uma ferramenta útil que pode ser facilmente aplicada na rotina de diagnóstico de tumores melanocíticos e contribuiria na avalição unificada entre patologistas, Entretanto, são necessários mais estudos para se avaliar a aplicação desta ferramenta com o prognóstico clínico. As mutações encontradas nas regiões avaliadas do gene tp53 aparentemente não foram relevantes para definir o diagnóstico nos tumores melanocíticos deste estudo.

Dogs are susceptible to melanocytic tumors and the survival of dogs with melanoma is generally small due to unfavorable prognosis. Research that helps in the discernment of the biological behavior and prognostic factors of this neoplasm in the canine species will allow establishing a more accurate diagnosis and prognosis. In this work two experiments were performed. The first one aimed at the histopathological and morphometric characterization of spontaneous cutaneous melanocytic neoplasm in canines. The second aimed at sequencing the tp53 gene in 25 melanocytic neoplasm. In both experiments, the cases were recovered from the biopsy file of the histopathology laboratories of the Federal University of Viçosa and the PROVET. In the experiment I, we recorded data of breed, sex and age of the animals, and size and location of tumors. Two pathologists evaluated the histological slides stained with hematoxylin and eosin and/or bleached to confirm the diagnosis and histopathological characterization: pigmentation, presence or absence of the pagetoid infiltrate, junctional activity, and ulceration. Mitotic index was determined and recorded for each tumor. The proportion of total cellularity, cell type, lymphocytic infiltrate, blood vessels and necrosis was determined. Nuclear pleomorphism was evaluated on a scale of 1 to 3 by 3 different pathologists, who did not share their diagnoses and interpretations, and the cases were classified according to the agreement of the three diagnoses. The area and diameters of epithelioid cells, spindle cells and erythrocyte nuclei were measured. In Experiment II, 25 canine cutaneous melanocytic neoplasms, fixed in buffered formalin and embedded in paraffin, were included in the study to detect mutations of the tp53 gene in exons 5 to 8. In Experiment I, Melanomas were larger than melanocytomas. Microscopically, melanocytomas were more pigmented compared to melanomas. The presence of pagetoid infiltrate was observed in both types of neoplasms and the junctional activity was observed in melanomas and melanocytomas with similar x frequencies. Ulceration was absent in most melanocytomas but was frequent in melanomas. The majority of the melanocytic lesions presented 3 cellular subtypes: rounded, epithelioid and spindle. Regarding the atypia/pleomorphism, melanocytomas presented a discrete degree, whereas the melanomas showed degrees from discrete to intense, with gradual increase of the mitotic index as the differentiation decreased. Furthermore, there was a significant difference for nuclear size between the degrees of atypia/pleomorphism of the tumors studied. Lymphocyte infiltrate was observed with greater intensity in melanomas, especially in grade 2 melanomas. The proportion of necrosis did not differ between melanocytomas and melanomas, but when the degree of atypia/ pleomorphism was considered, grade 3 melanomas had a higher percentage. In experiment II, all melanocytic neoplasms presented three base insertion (CT) at exon 5, and mutations in introns. In conclusion, the evaluation of atypia / pleomorphism in epithelioid cells is an efficient procedure, since these cells represent a large proportion in melanocytic tumors and are easier to evaluate than spindle cell nuclei. The atypia/ pleomorphism scale may be a useful tool to be easily applied in the diagnosis of melanocytic tumors routine, and might contribute to the unified assessment among pathologists; nevertheless, further studies are needed to evaluate the application of this tool with clinical prognosis. melanocytic tumors of this study. Mutations found in the evaluated regions of the tp53 gene apparently were not relevant to define the diagnosis in the melanocytic tumors of this study.

Lesões melanocíticas em suínos abatidos para consumo / Melanocytic lesions in pigs slaughtered for consumption

O presente estudo teve como principais objetivos conhecer a taxa de ocorrência de lesões melanocíticas (melanose, melanocitomas e melanomas) em suínos abatidos para consumo e identificar possíveis padrões de distinção e de classificação macroscópica dessas lesões. Para tal, procedeu-se à recolha de lesões melanocíticas em matadouro, durante oito meses, e à sua avaliação macroscópica e microscópica. Os resultados deste estudo demonstraram que as melanoses foram as lesões melanocíticas mais frequentemente encontradas (74,04%) e que, relativamente às lesões tumorais, os melanomas (malignos) foram os mais frequentes (21,15%) comparativamente com os melanocitomas (benignos) (4,81%). Pela análise comparativa das características macroscópicas e microscópicas, verificou-se que, nem sempre, por uma avaliação macroscópica, é possível a distinção entre essas lesões (melanoses, melanocitomas e melanomas). No entanto, identificaram-se, neste estudo, algumas características sugestivas da malignidade, como: o tamanho superior a 2,5cm, a presença de ulceração, a libertação de pigmento negro e a presença de coloração negra do gânglio linfático regional. É, portanto, de extrema importância a observação criteriosa e sistemática dessas lesões, para a avaliação das suas características, uma vez que a decisão sanitária é diferente consoante se trate de uma melanose, de um tumor maligno ou de um tumor benigno.(AU)

The main objective of the present study was to know the rate of occurrence of melanocytic lesions (melanosis, melanocytoma and melanoma) in pigs slaughtered for consumption and to identify possible patterns of differentiation and a macroscopic classification of these lesions. To this end, we proceeded to the collection of melanocytic lesions in a slaughterhouse during 8 months, and its macroscopic and microscopic evaluation. The results of this study demonstrated that melanosis were the most often found melanocytic lesions (74.04%) and that for tumors, melanomas (malignant) were the most frequent (21.15%) compared to melanocytomas (benign) (4.81%). By comparative analysis of macroscopic and microscopic characteristics we found that it is not always possible, with a macroscopic evaluation, to distinguish between these lesions (melanosis, melanocytoma and melanoma). However, in this study we identified some features suggestive of malignancy such as: size exceeding 2.5cm, the presence of ulceration, the release of black pigment and the presence of a black staining of the regional lymph node. Therefore, it is extremely important to make a careful and systematic observation of these lesions, with the evaluation of their characteristics, since the sanitary decision is different if they are melanosis, malignant tumors or benign tumors.(AU)

Melanoma ocular em cães: relato de dois casos / Ocular melanoma in dogs: report of two cases

Os melanomas normalmente são neoplasias cutâneas, mas podem ocorrer sempre que agrupamentos de melanócitos são encontrados. Estes tumores possuem duas categorias: melanoma benigno, referido como melanocitoma, e melanoma maligno. O local mais comum da sua ocorrência no cão é a cavidade oral, mas dentre as neoplasias oculares representam a mais comum neoplasia ocular primária nesta espécie. Quanto a sua localização podem ocorrer na conjuntiva, limbo (tecidos epibulbares), úvea anterior, coróide e nos anexos oculares. A localização anatômica destas neoplasias é de grande importância para a determinação do protocolo terapêutico mais adequado e consequentemente do seu prognóstico.

Melanomas are usually skin cancers, but may occur when clusters of melanocytes are found. These tumors have two classes: benign melanoma, referred to as melanocytoma, and malignant melanoma. The most common site of its occurrence is in the dogs mouth, but among ocular tumors represent the most common primary eye cancer in this species. Their location could be in the conjunctiva, limbus (epibulbar tissues), anterior uvea, choroid and eye annexes. The anatomical location of these neoplasms is of great importance to determine the most appropriate treatment protocol and therefore their prognosis.

Melanoma ocular em cães: relato de dois casos / Ocular melanoma in dogs: report of two cases

Os melanomas normalmente são neoplasias cutâneas, mas podem ocorrer sempre que agrupamentos de melanócitos são encontrados. Estes tumores possuem duas categorias: melanoma benigno, referido como melanocitoma, e melanoma maligno. O local mais comum da sua ocorrência no cão é a cavidade oral, mas dentre as neoplasias oculares representam a mais comum neoplasia ocular primária nesta espécie. Quanto a sua localização podem ocorrer na conjuntiva, limbo (tecidos epibulbares), úvea anterior, coróide e nos anexos oculares. A localização anatômica destas neoplasias é de grande importância para a determinação do protocolo terapêutico mais adequado e consequentemente do seu prognóstico.(AU)

Melanomas are usually skin cancers, but may occur when clusters of melanocytes are found. These tumors have two classes: benign melanoma, referred to as melanocytoma, and malignant melanoma. The most common site of its occurrence is in the dogs mouth, but among ocular tumors represent the most common primary eye cancer in this species. Their location could be in the conjunctiva, limbus (epibulbar tissues), anterior uvea, choroid and eye annexes. The anatomical location of these neoplasms is of great importance to determine the most appropriate treatment protocol and therefore their prognosis.(AU)

ESTUDO DA EXPRESSÃO DE -CATENINA E DO Ki-67 EM NEOPLASIAS MELANOCÍTICAS CANINAS

Este estudo, realizado no Laboratório de Patologia Animal da Faculdade de Agronomia e Medicina Veterinária da Universidade de Passo Fundo, trata da análise de 26 neoplasias melanocíticas caninas através de avaliação clínico-patológica e imuno-histoquímica com o objetivo de averiguar o padrão de marcação da molécula -catenina e se há correlação com a proliferação celular avaliada pela expressão do Ki-67, bem como se há correlação desses marcadores com os fatores clínico-patológicos. As neoplasias melanocíticas caninas originam-se da proliferação de melanócitos e são denominadas melanocitoma quando benignas e melanoma quando malignas. Melanomas apresentam mauprognóstico ocasionando metástases na maioria dos animais. O diagnóstico preciso é obtido através da associação dos fatores clínico-patológicos com a imuno-histoquímica, ferramenta necessária para estabelecer o prognóstico e a terapêutica adequada. Marcadores imuno-histoquímicos, como o Ki-67, são usados para melhorar a qualidade do prognóstico do melanoma humano e canino, pois possibilitam avaliar a taxa de proliferação celular. Este trabalho descreve dados referentes aos parâmetros clínico-patológicos das neoplasias melanocíticas primárias caninas benignas e malignas:cutâneas e orais, melanóticas e amelanóticas.Foram consideradas as variáveis:localização do tumor, ulceração macroscópica, idade e sexo dos animais, além da presença de necrose e ulceração microscópica, atipia nuclear e índice mitótico. Quanto ao local de marcação da -catenina, foi verificado se citoplasmática, nuclear ou mista. Os parâmetros clínico-patológicos que demonstraram significância foram: a idade dos animais afetados, a ulceração microscópica e necrose, a atipia nuclear e o índice mitótico, todos em relação aos melanomas. Não houve diferença estatística entre os locais de marcação da -catenina entre neoplasias melanociticas benignas ou malignas, bem como não foi observado correlação da molécula -catenina e o marcador Ki-67. Até o presente, não tem sido estudada a relação da expressão da molécula -catenina e a expressão do Ki-67 com os fatores prognósticos clínico-patológicos pré-estabelecidos.

This study, carried out at the Laboratory of Animal Pathology of the Faculty of Agronomy and Veterinary Medicine of the University of Passo Fundo, deals with the analysis of 26 canine melanocytic neoplasms through clinical-pathological and immunohistochemical evaluation, with the objective of ascertaining the marking pattern of the -catenin molecule and if there is a correlation with the cellular proliferation evaluated by Ki-67 expression, as well as if there is a correlation of these markers with clinical-pathological factors. Canine melanocytic neoplasms originate from the proliferation of melanocytes and are called melanocytoma when benign, and melanoma when malignant. Melanona present poor prognosis, causing metastases in most animals. The precise diagnosis is obtained through the association of clinical-pathological factors with immunohistochemistry, a necessary tool to establish the prognosis and appropriate therapy. Immunohistochemical markers, such as Ki-67, are used to improve the prognostic quality of human and canine melanoma, since they allow the evaluation of the rate of cell proliferation. This work described data on the clinical-pathological parameters of benign and malignant primary melanocytic neoplasms: cutaneous and oral, melanocytic and amelanotic. The variables were: tumor location, macroscopic ulceration, age and gender of the animals, as well as the presence of necrosis and microscopic ulceration, nuclear atypia and mitotic index. As for the labeling site of -catenin, it was verified whether cytoplasmic, nuclear or mixed. The clinical-pathological parameters that demonstrated significance were: the age of affected animals, microscopic ulceration and necrosis, nuclear atypia and mitotic index, all in relation to melanomas. There was no statistical difference between the -catenin labeling sites between benign or malignant melanocytic neoplasms, as well as no correlation between the -catenin molecule and the Ki-67 marker. To date, the relationship of -catenin expression and Ki-67 expression to pre-established clinical-pathological prognostic factors has not been studied.

TUMORES MELANOCÍTICOS CANINOS: CARACTERIZAÇÃO CLÍNICO-PATOLÓGICA E IMUNO-HISTOQUÍMICA

Tumores melanocíticos são comuns em cães e apresentam-se, quanto ao comportamento biológico, como benignos e malignos, sendo denominados melanocitoma e melanoma, respectivamente. Em humanos, a intensidade do infiltrado linfocitário tumoral (TIL) em melanomas cutâneos primários tem sido utilizada para avaliar a resposta imune antitumoral. O TIL tem exercido um importante papel, conferindo melhor prognóstico para estas neoplasias, além de estar associado à regressão tumoral. Os cães têm sido apontados como modelo para melanoma humano. Assim, com o intuito de avaliar o papel do TIL, verificar se há relação deste com variáveis prognósticas clinico-patológicas pré-estabelecidas e com o índice de proliferação celular e seu valor prognóstico foi realizado um estudo transversal e exploratório, com o uso de marcadores imuno-histoquímicos, a partir de junho de 2000 a setembro de 2016, em tumores melanocíticos primários caninos, diagnosticados no Laboratório de Patologia Animal da FAMV-UPF. Foram estudados 21 tumores, obtidos de 19 cães, dos quais 71,5% (15/21) correspondiam a melanomas melanóticos, 19,0% (4/21) melanocitomas, e 9,5% (2/21) melanomas amelanóticos. Cães geriátricos estiveram associados à presença de melanomas melanóticos. Não houve predisposição por sexo ea maioria dos tumores era oriunda do tecido cutâneo 71,5% (15/21). À confirmação diagnóstica, foi observado positividade de 92,5% para Melan-A, 87,5% para S-100 e 81% para HMB-45. Histologicamente, a maioria dos casos foi classificada como epitelioide57,1% (12/21). Melanomas estiveram associados à necrose, ulceração, atipia e elevado índice mitótico.Melanomas amelanóticos apresentaram elevada expressão de Ki67, sugerindo comportamento agressivo. O TIL apresentou forte correlação com os tumores malignos e com outros fatores prognósticos pré-estabelecidos, como necrose, ulceração e atipia nuclear. Linfócitos T são importantes na resposta imune antitumoral, contudo novos estudos são necessários para estabelecer os subtipos de linfócitos T presentes nos melanomas primários caninos na tentativa de elucidar o papel exercido por esta população e o comportamento da neoplasia.

Melanocytic tumors are common in dogs and are present, regarding the biological behavior, as benign and malignant, being denominated melanocytoma and melanoma, respectively. In humans, the intensity of tumor lymphocytic infiltrate (TIL) in primary cutaneous melanomas has been used to evaluate the antitumoral immune response. The TIL has played an important role, assershing a better prognosis for these neoplasias, besides being associated with tumor regression. Dogs have been appointed as a model for human melanoma. So, in the intent to evaluate the role of TIL, verify if there is a relation of this one with pre-established clinicalpathological prognostic variables and with the index of cellular proliferation and its prognostic value, a transversal and exploratory study was carried with the use of immunohistochemical markers starting from June 2000 to September 2016, in canine primary melanocytic tumors diagnosed at the Animal Pathology Laboratory of FAMV-UPF. Were studied 21 tumors obtained from 19 dogs, of which 71.5% (15/21) corresponded to melanotic melanomas, 19.0% (4/21) melanocytomas, and 9.5% (2/21) amelanotic melanomas. Geriatric dogs were associated with the presence of melanotic melanomas.There was no predisposition by sex and most of the tumors came from the cutaneous tissue 71.5% (15/21). At the diagnostic confirmation, 92.5% positivity was observed for Melan-A, 87.5% for S-100 and 81% for HMB-45. Histologically, the majority of cases were classified as epithelioid 57.1% (12/21). Melanomas were been associated with necrosis, ulceration, atypia and high mitotic index. Amelanotic melanomas presented high Ki67 expression, suggesting aggressive behavior. The TIL showed a strong correlation with malignant tumors and other preestablished prognostic factors, such as necrosis, ulceration and nuclear atypia. The T lymphocytes are important on the immune antitumoral response, however, new studies are needed to establish the subtypes of the lymphocytes present in canine primary melanomas in an attempt to elucidate the role played by this population and the behavior of the neoplasia.

Avaliação da expressão das galectinas no melanoma canino

O melanoma canino é uma neoplasia frequente em cães, tem um caráter maligno, invasivo, com potencial metastático e, neste contexto, estudos acerca do envolvimento das galectinas se justifica para ampliar o conhecimento do microambiente tumoral desta neoplasia. As galectinas são proteínas da família das lectinas animais que apresentam domínios de reconhecimento de carboidratos e podem estar localizadas no núcleo, no citoplasma, na superfície de células e secretadas em diversos tecidos. Acredita-se que principalmente a galectina-1 (gal-1) e a galectina-3 (gal-3) estejam associadas à transformação neoplásica, sobrevivência da célula neoplásica, angiogênese, evasão do sistema imune e formação de metástases. A gal-1 está principalmente relacionada com a transformação tumoral e evasão do sistema imune. A gal-3 está principalmente associada com a angiogênese, desenvolvimento de metástases pelo aumento da motilidade e adesão entre as células neoplásicas e adesão entre as células neoplásicas e o endotélio, além de contribuir para a evasão do sistema imune. O objetivo do estudo foi verificar o padrão de expressão de gal-1 e gal-3 nos diferentes graus de agressividade do melanoma canino, além de avaliar a concentração sérica de gal-3 e comparar com cães clinicamente saudáveis. Foram analisadas a expressão de gal-1 e gal-3 em 30 fragmentos de melanoma canino, seis fragmentos de melanocitoma e nove fragmentos de linfonodos metastáticos. Foi realizada a dosagem sérica de gal-3 em 30 cães com melanoma e comparada a 10 cães clinicamente saudáveis. O melanoma canino expressou gal-1 principalmente no citoplasma e expressou um padrão variável de gal-3 no citoplasma e no núcleo. Em relação à expressão de gal-3 observou-se que conforme a agressividade do melanoma houve diminuição da frequência de células com marcação citoplasmática e um aumento da intensidade de marcação nuclear com concomitante diminuição da frequência de células com marcação nuclear. Os cães com melanoma apresentaram aumento dos níveis séricos de gal-3 antes da exérese da neoplasia quando comparados aos animais clinicamente saudáveis, mostrando o seu potencial uso como biomarcador do melanoma.

Canine melanoma is a frequent neoplasm in dogs. It has a malignant, invasive and metastatic potential. In this context, studies about the involvement of galectins are justified to increase the knowledge of melanoma tumor microenvironment. Galectins are proteins of the animal lectins family, that display carbohydrate recognition domains and may be located in the nucleus, cytoplasm, cell surface, as well as secreted in various tissues. Galectin-1 (Gal-1) and galectin-3 (Gal-3) are associated with neoplastic transformation, neoplastic cell survival, angiogenesis, immune system evasion, and metastasis formation. Gal-1 is mainly related to tumor transformation and immune system evasion. Gal-3 is mainly associated with angiogenesis, development of metastasis by increased motility and adhesion between neoplastic cells and adhesion between neoplastic cells and endothelium, while contributing to the evasion of the immune system. The aim of the study was to ascertain the expression pattern of Gal-1 and Gal-3 in different severity degrees of canine melanoma, as well as to evaluate the serum concentration of Gal-3 and to compare with clinically healthy dogs. Gal-1 and Gal-3 expression was analyzed in 30 canine melanoma fragments, six melanocytoma fragments and nine fragments of metastatic lymph nodes. Serum Gal-3 was measured in 30 dogs with melanoma and compared to 10 clinically healthy dogs. Canine melanoma expressed Gal-1 primarily in the cytoplasm and presented a variable pattern of Gal-3 in the cytoplasm and nucleus. Regarding the expression of Gal-3, it was observed that according to melanoma severity, there was a decrease in the percent frequence of cells with cytoplasmic labeling and an increase in the nuclear marking intensity with concomitant decrease in the percent frequency of nuclear-labeled cells. Dogs with melanoma had increased serum levels of Gal-3 before the excision of the neoplasia when compared to the clinically healthy animals, showing its potential use as a melanoma biomarker.

Cutaneous tumors in dogs - A retrospective study of ten years

In this study were used 662 samples of skin tumors, from 644 dogs, originating from regions of the State of São Paulo, Brazil, between January 1998 and January 2008. The samples were obtained from necropsies (1.66%) and surgical excision (98.33 %). Twenty-three different types of skin tumors were diagnosed, with some animals affected (1.70%) by more than one morphological type. The mesenchymal tumors were categorized into eight different histological types with great occurrence (53.92%) followed by epithelial tumors (12 types; 35.04%), melanocytic tumors (one type; 6.64%) and hematopoietic tumors (two types; 4.38%). Mastocytoma, histiocytoma, squamous cell carcinoma, fibrosarcoma and melanocytoma were the most common tumors, accounting for just over 50% of all the cutaneous neoplasia. There were 53,27% of females and 46.73% of males; 72.81% of the dogs were purebred, while 27.19% were mongrels. The malignant tumors (59.51%) were more frequent than the benign tumors (40.49%). The occurrences of epithelial, mesenchymal and melanocytic tumors were statistically greater among dogs aged six to eleven years. Hematopoietic tumors were more frequent among animals aged zero to eight years. These results are important for small-animal clinics. They serve as a further tool to direct the diagnosing of cutaneous neoplasia in dogs as rapidly and precisely as possible.

Neoplasias melanocíticas cutâneas em cães: estudo retrospectivo de 68 casos (1996-2004) / Cutaneous melanocytic neoplasms in dogs: retrospective study of 58 cases (1996-2004)

Foram analisados 39 casos (42 lesões) de melanocitoma e 19 casos (19 lesões) de melanoma cutâneos caninos. Os melanocitomas acometeram tanto animais jovens como idosos, sem predisposição sexual. Neste estudo, os cães mais acometidos foram os da raça Schnauzer e Doberman, seguidos por aqueles sem raça definida. A maioria das lesões apresentou-se solitária e localizada na região palpebral, interdigital e torácica. Geralmente, as lesões eram papulares, alopécicas, não aderidas, enegrecidas, com consistência firme e diâmetro médio de 1,2 cm. Recidivas e metástases não foram observadas, confirmando o bom prognóstico associado aos melanocitomas. Os melanomas acometeram animais mais idosos, sem predisposição sexual. Os cães mais acometidos foram os sem raça definida, seguida por aqueles das raças Rottweiler, Pinscher, Cocker Spaniel e Airedale. As lesões apresentaram-se solitárias e localizadas freqüentemente no lábio e na pálpebra. A maioria dos tumores apresentou-se ulcerado, nodular, com consistência firme e diâmetro médio de 2,5 cm. Algumas lesões apresentaram recidivas. Metástases não puderam ser comprovadas. Dos casos com seguimento clínico conhecido, alguns foram curados pelo procedimento cirúrgico, entretanto, a maioria evoluiu para óbito, confirmando o prognóstico ruim associado ao melanoma.(AU)

Thirty nine cases (42 lesions) of melanocytoma and nineteen cases (19 lesions) of canine cutaneous melanoma were analyzed. The melanocytomas affected the young animals as well as the old ones, without a sexual predisposition. The most affected dogs were the ones of the Schnauzer and Doberman breed, being followed by those without a defined breed. Most lesions appeared solitarily and located in the eyelid, interdigital and thorax regions. In general, the lesions were papuled, no haired, non adhering, black colored, with a firm consistency and a mean diameter of 1,2 cm. Recurrence and metastases were not seen. Such fact confirms the good prognostic associated to melanocytomas. The melanomas affected the older animals, without a sexual predisposition. The most affected dogs were the ones without a defined breed, being followed by those of the Rottweiler, Pinscher, Cocker Spaniel and Airedale breeds. The lesions appeared solitarily and located on the lips and eyelid. Most tumors were ulcerated and nodular, with a firm consistency, with a mean diameter of 2,5cm. Some lesions presented recurrence. Metastases could not be proven. Among the cases with a known clinical segment, some were cured through a surgical procedure, however, the majority died, probably related to a neoplastic disease, confirming the bad prognostic related to melanoma.(AU)

Expressão de marcadores imunoistoquímicos em neoplasias melanocíticas de equinos por microarranjo de tecidos / Expression of immunohistochemical biomarkers in equine melanocytic neoplasms using tissue microarray

O objetivo deste estudo foi verificar o comportamento morfológico e a expressão das proteínas S-100, Melan-A, HMB-45, Ki-67, PCNA e p53, em 25 neoplasias melanocíticas de equinos. Informações clínicas (gênero, raça, pelagem, idade e localização da lesão) e morfológicas (características celulares, pigmentares, nucleares, de nucléolo, de melanófagos, presença de invasão e necrose) dos animais foram coletadas. Para a expressão das proteínas por imunoistoquímica foi confeccionado um bloco de microarranjo de tecidos das amostras teciduais, juntamente com os controles positivos das reações. A avaliação da expressão das proteínas S100, HMB-45 e Melan-A foi baseada em um escore, e a das proteínas Ki-67, PCNA e p53 foi feita por contagem de células. Animais SRD (16/25, 64%), de raça Lusitana (6/25, 24%), Árabe (2/25, 8%) e Sueca (1/25, 4%) fizeram parte deste estudo, todos tordilhos e a maioria machos (18/25, 72%). A idade dos animais variou de 4 a 24 anos (média de 13 anos). A região perianal (13/25, 52%) foi a que mais apresentou neoplasias. Na análise morfológica houve predomínio de neoplasias com celularidade moderada (52%) e intensa (40%), distribuição difusa e em feixes (52%), ausência de figuras de mitose (96,0%) e predomínio de células epitelióides e fusiformes no mesmo tumor (80%). A atipia nuclear era discreta (48%) e moderada (44%), com núcleos de formato arredondado e alongado em um mesmo tumor (76%) e cromatina dispersa (60%). Os nucléolos eram múltiplos e, em sua maioria, proeminentes (88%). Observou-se predomínio de células tumorais de pigmentação intensa (68%), distribuição difusa e localização em derme (100%). A maioria dos casos apresentou alta celularidade de macrógafos (64%) e distribuição difusa (96%). Quanto à expressão de proteínas para melanócitos por imunoistoquímica, 44% dos casos apresentaram expressão moderada a forte de S100, 56% apresentaram expressão fraca de HMB-45 e 64% apresentaram expressão negativa de Melan-A. Houve positividade de 72% dos casos para pelo menos dois dos anticorpos citados acima. Os anticorpos de proliferação celular Ki-67 e PCNA tiveram média de acima. Os anticorpos de proliferação celular Ki-67 e PCNA tiveram média de positividade de 0,0005% e 15,7%, respectivamente. A análise da expressão de p53 teve média de 6,1% de positividade. Houve associação estatisticamente positiva entre a celularidade dos macrófagos com S100 e com p53. Em conclusão: 1. os dados clínicos obtidos reproduzem o comportamento biológico das neoplasias melanocíticas em equinos, exceto pela idade dos animais; 2. as neoplasias equinas se assemelham a nevos azuis celulares em humanos e melanocitomas em cães; 3. o microarranjo de tecidos mostrou-se uma maneira econômica, rápida e com menos variáveis técnicas; 4. a utilização de um painel de anticorpos de melanócitos é pertinente na diferenciação entre tumores melanocíticos e não melanocíticos, reproduzindo o painel diagnóstico utilizado em literatura humana e canina; 5. o índice de proliferação celular encontrado sugere que os dois anticorpos (Ki-67 e PCNA) podem ser usados na contagem de células em atividade mitótica e 6. a proteína p53 tem maior relação com a parada do ciclo celular que a observada em outros estudos em equinos, podendo indicar um comportamento biológico diferente do apresentado em cães e humanos

The aim of this study was to evaluate the morphological behavior, and expression of the following proteins: S-100, Melan-A, HMB-45, Ki-67, PCNA and p53, in 25 equine melanocytic neoplasms. Clinical (gender, breed, coat color, age and lesions location) and morphological (cellular, pigment, nuclear, nucleoli, melanophages, invasion and necrosis) data were collected. A tissue microarray block, embedded in paraffin, with equine tissue samples and positive controls, was elaborated for protein expression through immunohistochemistry. The evaluation of S100, HMB-45 and Melan-A was based on a score, and for Ki-67, PCNA and p53 it was based on cellular count. Breeds were: Mixed breed (16/25, 64%), Lusitano (6/25, 24%), Arab (2/25, 8%) and Swedich (1/25, 4%). All animals were gray and the majority males (18/25, 72%). Age varied from 4 to 24 years old (mean=13 years). The perianal region (13/25, 52%) was the most common location. Morphological analysis have shown neoplasms with predominantly moderate (52%) and intense (40%) cellularity, diffuse and fascicles distribution (52%), no mitoses figures (96%) and predominance of epithelioid and spindle cells in the same tumor (80%). There was discrete (48%) and moderate (44%) nuclear atypia, round and elongated nucleus in the same tumor (76%), and disperse chromatin (60%). Nucleoli were multiple and prominent in the majority of cases (88%). Tumor cells with diffuse and intense pigmentation, with dermal location (100%) were predominant. High cellularity of macrophages (64%) with diffuse distribution (96%) was mostly seen. The protein expression for melanocytes have shown 44% of moderate to strong expression for S100 protein, 56% of weak expression for HMB-45 protein and 64% of negative expression for Melan-A protein. It was found positivity for more than two antibodies in 72% of equine melanocytic neoplasms. The proliferation antibodies Ki-67 and PCNA had mean positivity of 0,0005% and 15,7%, respectively. The p53 expression had mean positivity of 6,1%. Macrophages cellularity was statistically associated with S100 and p53. In conclusion: 1. clinical data obtain reproduce the biological behavior of equine Macrophages celllularity was statistically associated with S100 and p53. In conclusion: 1. clinical data obtain reproduce the biological behavior of equine melanocytic neoplasms, excepting the animals age; 2. equine melanocytic neoplasms assemble to human cellular blue nevi and dogs melanocytoma; 3. the tissue microarray was shown to be an economic, rapid and less variable technique; 4. using a panel for antibodies for melanocytes is relevant to differentiate melanocytic and not melanocytic tumors, reproducing the diagnosis panel used in human and canine literature; 5. the proliferation index found suggests that both antibodies (Ki-67 and PCNA) could be used in mitotic activity cell count; and 6. p53 protein has more relation with cellular cycle stop than in other equine studies, probably indicating a different biological behavior than the presented in humans and dogs

Cutaneous tumors in dogs - A retrospective study of ten years

In this study were used 662 samples of skin tumors, from 644 dogs, originating from regions of the State of São Paulo, Brazil, between January 1998 and January 2008. The samples were obtained from necropsies (1.66%) and surgical excision (98.33 %). Twenty-three different types of skin tumors were diagnosed, with some animals affected (1.70%) by more than one morphological type. The mesenchymal tumors were categorized into eight different histological types with great occurrence (53.92%) followed by epithelial tumors (12 types; 35.04%), melanocytic tumors (one type; 6.64%) and hematopoietic tumors (two types; 4.38%). Mastocytoma, histiocytoma, squamous cell carcinoma, fibrosarcoma and melanocytoma were the most common tumors, accounting for just over 50% of all the cutaneous neoplasia. There were 53,27% of females and 46.73% of males; 72.81% of the dogs were purebred, while 27.19% were mongrels. The malignant tumors (59.51%) were more frequent than the benign tumors (40.49%). The occurrences of epithelial, mesenchymal and melanocytic tumors were statistically greater among dogs aged six to eleven years. Hematopoietic tumors were more frequent among animals aged zero to eight years. These results are important for small-animal clinics. They serve as a further tool to direct the diagnosing of cutaneous neoplasia in dogs as rapidly and precisely as possible.