Melanomas em cães no Sertão do Nordeste do Brasil - epidemiologia, fatores de risco e achados clinicopatológicos / Melanoma in dogs in the backlands of Northeastern Brazil - epidemiology, risk factors and clinicopathological findings

Background: Melanoma is a malignant neoplasm that arises from melanocytes and malanoblasts. It is also more frequently reported in dogs than in other species. They may arise from melanocytes in the skin, on the surfaces of the mucous membranes, and eyes. The aim of this study was to describe the epidemiological aspects, risk factors and clinicopathological findings of melanoma in dogs in the backlands, northeastern Brazil. Materials, Methods & Results: A retrospective study was carried out in all biopsy samples and necropsy examinations of dogs, from January 2003 to December 2021, at the Animal Pathology Laboratory of the Federal University of Campina Grande, Patos, Paraiba, northeastern Brazil. Epidemiological data, clinical signs, and gross lesions were reviewed from the diagnostic laboratory reports. Samples of the skin, lymph nodes, central nervous system and organs of the thoracic and abdominal cavities were fixed in 10% buffered formalin, processed routinely for histopathology, embedded in paraffin wax, cut into 4 µm sections, and stained with hematoxylin and eosin (HE). Histological sections were also submitted to immunohistochemistry with the primary antibody anti-Melan A. Of the 4717 records found, 1158 (24.5%) were diagnosed with neoplasms, of which 48 (4.14%) cases were of melanoma. Of this total, 28 (58.3%) dogs were elderly, 19 (39.6%) were adults, and 1 (2.1%) was young. Mixed breed animals were the most affected (42.6%), followed by the pinscher breed (19.1%). According to the anatomical region, the most affected site was the skin (38/53=71.7%), followed by the oral cavity (12/53=22.65%) and the eyes (3/53=5.7%). Grossly, the skin lesions were characterized by exophytic and usually blackened, sometimes irregular and firm, nodules. At cut, they had a smooth, compact and blackened surface. Lesions in the oral cavity were characterized by blackened, irregular and infiltrating nodules or masses. The ocular lesions were always unilateral and were characterized by an enlarged and diffusely blackened eyeball, with areas of ulceration and subversion of tissue architecture. In 5 animals there was more than one anatomical site affected, totaling 53 lesions. In 9 (17%) cases, metastases were identified, 8 in regional lymph nodes and 1 in the lung. Histopathology showed a densely non-encapsulated, poorly delimited, expansive and infiltrative neoplasm, composed of neoplastic cells arranged in islands or nests and supported by fibrovascular stroma, containing a variable amount of brownish pigment (melanin). Immunohistochemistry showed strong immunostaining of the neoplastic cells in brown by the anti-Melan A antibody. Discussion: The diagnosis of melanoma was established based on epidemiological, clinical, anatomopathological, and immunohistochemical findings. Gender is not a predisposing factor, and although there was no statistically significant relationship, males were more affected. Senescence is a conditioning risk factor. Elderly animals were more affected (P < 0.0001) than adult ones, with OR = 4.38; and young ones (P = 0.0051), with OR = 12.65. Some breeds, especially those with marked skin pigmentation, were more affected, however the most affected ones in this survey were pinscher and poodle. Cutaneous melanoma accounted for almost 72% of cases, contesting recent studies where oral cavity melanoma was more frequent. Therefore, it is believed that the climatic conditions of the backlands sub-region, in northeastern Brazil, associated with the individual characteristics of the dogs, are involved in the development of these neoplasms, since the climate is predominantly dry, with high temperatures throughout the year, with maximums that can reach 40ºC, favoring the exposure to high incidence of ultraviolet radiation.

Cryosurgery using dimethyl ether in the treatment of pigmentary keratitis in pug dogs / Criocirurgia usando o dimethyl ether no tratamento da ceratite pigmentar em cães da raça Pug

Corneal pigmentation and vascularization eventually result in blindness in dogs. Pigmentary keratitis describes a relatively common presentation comprising the deposition of melanin in the cornea and conjunctival surface associated with chronic inflammation. Cryosurgery is indicated as a treatment for pigmentary keratitis in dogs. Due to melanocytes sensitivity to cold, cryosurgery is a viable treatment for severe refractory corneal pigmentation. The aim of this work was to evaluate the use of dimethyl ether in the treatment of pigmentary keratitis in 14 eyes of seven Pug dogs. Follow-up occurred after 30 days in four animals and six months in three animals. In all treated animals, there was a reduction in corneal pigmentation. Cryosurgery causes intracellular and extracellular ice crystal formation and other mechanisms that result in rupture and death of the melanocytes. The technique used was easy to perform, has a low cryogen cost and has few undesirable or serious side effects. However, after 30 days repigmentation occured in treated patients. Cryosurgery shows good results in the first four weeks, but partial recurrence occurred in all cases.

A pigmentação e a vascularização da córnea eventualmente resultam em cegueira em cães. A ceratite pigmentar é descrita com uma apresentação relativamente comum que compreende a deposição de melanina na córnea e na superfície conjuntival associada à inflamação crônica. A criocirurgia é indicada como tratamento para ceratite pigmentar em cães. Devido à sensibilidade dos melanócitos ao frio, a criocirurgia é um tratamento viável para pigmentação corneana refratária grave. O objetivo deste trabalho foi avaliar o uso do éter dimetílico no tratamento da ceratite pigmentar em 14 olhos de sete cães da raça Pug. O acompanhamento foi de 30 dias em quatro animais e seis meses em três animais. Em todos os animais tratados, houve redução da pigmentação da córnea. A criocirurgia causa a formação de cristais de gelo intracelular e extracelular e outros mecanismos que resultam na ruptura e morte dos melanócitos. A técnica utilizada foi de fácil execução, baixo custo de criogenia e poucos efeitos colaterais indesejáveis ou graves. No entanto, após 30 dias, ocorreu repigmentação nos pacientes tratados. A criocirurgia apresenta bons resultados nas primeiras quatro semanas, mas ocorreu recidiva parcial em todos os casos.

Diffuse melanosis secondary to metastatic melanoma in a Nelore bull

Relatamos um caso de melanose difusa secundária a melanoma maligno metastático em um touro Nelore. Os sinais clínicos incluíram isolamento do rebanho, epistaxe, hipertermia, pálidas membranas oculares, diarreia mucóide e urina escura. Apesar da terapia antiinflamatória e antibiótica, o touro morreu 45 dias após o início dos sinais clínicos. A lesão mais marcante foi uma descoloração negra difusa para os órgãos viscerais, incluindo fígado, baço, pulmões, nódulos linfáticos e rins; todos esses órgãos afetivos foram moderadamente aumentados ”. A urina estava preta. Histologicamente, 50-80% do parênquima do fígado, baço e linfonodos foi obliterado por agregados de melanócitos neoplásicos carregados de melanina. Essas células neoplásicas também ocorreram nos capilares do fígado, baço, linfonodos, bexiga urinária, pulmões e rins. A imunohistoquímica de melanócitos neoplásicos foi positiva para os marcadores Melan A e PNL2. Pigmento marrom a preto abundante foi encontrado em melanófagos nos pulmões, confirmado por imunohistoquímica com IBA1.

Diffuse melanosis secondary to metastatic melanoma in a Nelore bull

Relatamos um caso de melanose difusa secundária a melanoma maligno metastático em um touro Nelore. Os sinais clínicos incluíram isolamento do rebanho, epistaxe, hipertermia, pálidas membranas oculares, diarreia mucóide e urina escura. Apesar da terapia antiinflamatória e antibiótica, o touro morreu 45 dias após o início dos sinais clínicos. A lesão mais marcante foi uma descoloração negra difusa para os órgãos viscerais, incluindo fígado, baço, pulmões, nódulos linfáticos e rins; todos esses órgãos afetivos foram moderadamente aumentados ”. A urina estava preta. Histologicamente, 50-80% do parênquima do fígado, baço e linfonodos foi obliterado por agregados de melanócitos neoplásicos carregados de melanina. Essas células neoplásicas também ocorreram nos capilares do fígado, baço, linfonodos, bexiga urinária, pulmões e rins. A imunohistoquímica de melanócitos neoplásicos foi positiva para os marcadores Melan A e PNL2. Pigmento marrom a preto abundante foi encontrado em melanófagos nos pulmões, confirmado por imunohistoquímica com IBA1.(AU)

Vitiligo in equine: a four-year case study of a roan horse - case report / [Vitiligo em equinos: um estudo de caso de quatro anos de um cavalo roan - relato de caso]

Vitiligo is a dermatological disease affecting both animals and humans. It is characterized by depigmented macules of varying shape and size, originated from melanocyte destruction. Even though there are some theories tackling causation, disease etiopathology is not yet certain. Moreover, lesion areas can either increase or diminish over time, and therefore, available treatment alternatives tend to prove inconsistencies. No epidemiological data or registered cases were found for equines in Brazil. The horse in this case description displayed depigmentation areas in facial regions, including upper lip, nose and lips. However, the individual did not happen to develop any systemic alteration. Through clinical evaluation, backed by a histopathological exam, a definitive vitiligo diagnosis was obtained. However, no therapeutic plan was stipulated. The animal was accompanied for four years, during which period some affected areas diminished while others increased in size. In addition, emergence of new skin lesions was also observed during the time the animal was studied. Overall, this disease does not display alterations to organism functionality, only aesthetic changes. Therefore, treatment plans may vary from case to case, occasionally being even ruled out.(AU)

O vitiligo é uma doença dermatológica que pode afetar animais e humanos. Caracteriza-se por áreas despigmentadas, de formas e tamanhos variáveis, que surgem devido a destruição dos melanócitos. Existem algumas teorias que tentam explicar a etiopatogenia da doença, entretanto ainda não é totalmente esclarecida. As lesões podem aumentar ou diminuir com o tempo, por isso os tratamentos disponíveis são inconsistentes. Não foram encontrados dados epidemiológicos ou relatos de vitiligo em cavalos no Brasil. O equino deste relato apresentava lesões despigmentadas na região da face, incluindo pálpebras, narina e lábios, sem alterações sistêmicas. Por meio da avaliação clínica em conjunto com o exame histopatológico obteve-se o diagnóstico definitivo de vitiligo. Não foi instituído nenhuma terapia, e o equino foi acompanhado durante quatro anos. Durante esse período algumas lesões diminuíram e outras aumentaram de tamanho sendo também observado o aparecimento de novas lesões. O vitiligo não traz alterações sistêmicas, apenas mudanças estéticas, por isso a escolha pelo tratamento dependerá de cada caso.(AU)

Ultrastructural and morphometric description of the ear skin and cartilage of two South American wild histricognate rodents (Dasyprocta leporina and Galea spixii) / Descrição ultraestrutural e morfométrica da pele e cartilagem auricular de dois roedores histricognatos silvestres da América do Sul (Dasyprocta leporina e Galea spixii)

Skin and cartilage have been the main source for the recovery of somatic cells to be used in conservation strategies in wild mammals. In this sense, an important step for the cryopreservation of these samples is to recognize the properties of the skin and cartilage. Thus, knowing that the skin may differ among species and aiming to contribute to the establishment of cryobanks, the study examined the differences in the ear skin and cartilage of wild rodents from South America, agouti (Dasyprocta leporina) and spix's yellow-toothed cavy (Galea spixii). Ultrastructural and quantitative methods were used to measure skin and cartilage thickness, density of collagen and elastic fibers, cell type number and distribution, and proliferative activity. Although ultrastructural analysis revealed a similar pattern between species, morphometric analysis of the skin and cartilage showed differences between agoutis and cavies regarding thickness of epidermis layers (corneum: 5.3±2.5μm vs. 3.9±0.6μm; intermediate: 16.4±6.2μm vs. 23.4±8.1μm; basal: 9.9±2.1μm vs. 4.8±0.5μm), dermis (183.1±44.0μm vs. 258.2±22.9μm), total skin (211.8±46.0μm vs. 290.3±23.7μm) and perichondrium (27.6±6.1μm vs. 10.5±1.8μm). A greater number of epidermal cells (61.7±15.2 vs. 24.8±7.6) and chondrocytes (32.7±9.0 vs. 27.5±4.7) were observed in agouti, while the cavy presented a greater number of melanocytes (12.6±4.7 vs. 29.9±6.2), keratinocytes (14.7±4.2 vs. 29.8±7.6), and fibroblasts (103.6±24.7 vs. 112.2±11.3). Moreover, a higher percentage of collagen fibers and proliferative activity was observed in the skin of cavies, when compared to the skin of agoutis. Therefore, there are differences between agouti and cavy for ear skin and cartilage, requiring the establishment of species-specific cryopreservation protocols.(AU)

A pele e cartilagem têm sido uma importante fonte de recuperação de células somáticas a serem utilizadas em estratégias de conservação em mamíferos silvestres. Nesse contexto, uma importante etapa para criopreservação é conhecer, inicialmente, as propriedades que compõem a pele e cartilagem. Sabendo, então, que a pele pode diferir-se entre espécies e com o objetivo de contribuir para o estabelecimento de criobancos, o estudo evidenciou as diferenças da pele e da cartilagem do pavilhão auricular apical de cutias (Dasyprocta leporina) e preás (Galea spixii) que são roedores silvestres presentes na América do Sul. Para tanto, métodos ultraestruturais e quantitativos foram utilizados para mensurar a espessura da pele e da cartilagem, densidade de fibras colágenas e elásticas, número e distribuição dos tipos celulares e atividade proliferativa. Embora as propriedades ultraestruturais em cutias e preás tenham se mostrado semelhantes, avaliações acerca da morfometria da pele e da cartilagem demonstrou diferenças, especialmente nas camadas epidérmicas (córnea: 5,3±2,5μm vs. 3,9±0,6μm; espinhosa: 16,4±6,2μm vs. 23,4±8,1μm; basal: 9,9±2,1μm vs. 4,8±0,5μm), derme (183,1±44,0μm vs. 258,2±22,9μm), pele total (211,8±46,0μm vs. 290,3±23,7μm) e pericôndrio (27,6±6,1μm vs. 10,5±1,8μm). Além disso, um número maior de células epidérmicas (61,7±15,2 vs. 24,8±7,6) e condrócitos (32,7±9,0 vs. 27,5±4,7) foram observados em cutias, enquanto em preás um maior número de melanócitos (12,6±4,7 vs. 29,9±6,2), queratinócitos (14,7±4,2 vs. 29,8±7,6) e fibroblastos (103,6±24,7 vs. 112,2±11,3) foram evidenciados. Ainda, em preás, uma maior porcentagem de fibras colágenas e da atividade proliferativa foram observadas quando comparadas a pele de cutias. Portanto, existem diferenças entre cutias e preás para pele e cartilagem do pavilhão auricular, exigindo desta forma um estabelecimento de protocolos de criopreservação específica para cada uma destas espécies.(AU)

Ultrastructural and morphometric description of the ear skin and cartilage of two South American wild histricognate rodents (Dasyprocta leporina and Galea spixii) / Descrição ultraestrutural e morfométrica da pele e cartilagem auricular de dois roedores histricognatos silvestres da América do Sul (Dasyprocta leporina e Galea spixii)

Skin and cartilage have been the main source for the recovery of somatic cells to be used in conservation strategies in wild mammals. In this sense, an important step for the cryopreservation of these samples is to recognize the properties of the skin and cartilage. Thus, knowing that the skin may differ among species and aiming to contribute to the establishment of cryobanks, the study examined the differences in the ear skin and cartilage of wild rodents from South America, agouti (Dasyprocta leporina) and spix's yellow-toothed cavy (Galea spixii). Ultrastructural and quantitative methods were used to measure skin and cartilage thickness, density of collagen and elastic fibers, cell type number and distribution, and proliferative activity. Although ultrastructural analysis revealed a similar pattern between species, morphometric analysis of the skin and cartilage showed differences between agoutis and cavies regarding thickness of epidermis layers (corneum: 5.3±2.5μm vs. 3.9±0.6μm; intermediate: 16.4±6.2μm vs. 23.4±8.1μm; basal: 9.9±2.1μm vs. 4.8±0.5μm), dermis (183.1±44.0μm vs. 258.2±22.9μm), total skin (211.8±46.0μm vs. 290.3±23.7μm) and perichondrium (27.6±6.1μm vs. 10.5±1.8μm). A greater number of epidermal cells (61.7±15.2 vs. 24.8±7.6) and chondrocytes (32.7±9.0 vs. 27.5±4.7) were observed in agouti, while the cavy presented a greater number of melanocytes (12.6±4.7 vs. 29.9±6.2), keratinocytes (14.7±4.2 vs. 29.8±7.6), and fibroblasts (103.6±24.7 vs. 112.2±11.3). Moreover, a higher percentage of collagen fibers and proliferative activity was observed in the skin of cavies, when compared to the skin of agoutis. Therefore, there are differences between agouti and cavy for ear skin and cartilage, requiring the establishment of species-specific cryopreservation protocols.(AU)

A pele e cartilagem têm sido uma importante fonte de recuperação de células somáticas a serem utilizadas em estratégias de conservação em mamíferos silvestres. Nesse contexto, uma importante etapa para criopreservação é conhecer, inicialmente, as propriedades que compõem a pele e cartilagem. Sabendo, então, que a pele pode diferir-se entre espécies e com o objetivo de contribuir para o estabelecimento de criobancos, o estudo evidenciou as diferenças da pele e da cartilagem do pavilhão auricular apical de cutias (Dasyprocta leporina) e preás (Galea spixii) que são roedores silvestres presentes na América do Sul. Para tanto, métodos ultraestruturais e quantitativos foram utilizados para mensurar a espessura da pele e da cartilagem, densidade de fibras colágenas e elásticas, número e distribuição dos tipos celulares e atividade proliferativa. Embora as propriedades ultraestruturais em cutias e preás tenham se mostrado semelhantes, avaliações acerca da morfometria da pele e da cartilagem demonstrou diferenças, especialmente nas camadas epidérmicas (córnea: 5,3±2,5μm vs. 3,9±0,6μm; espinhosa: 16,4±6,2μm vs. 23,4±8,1μm; basal: 9,9±2,1μm vs. 4,8±0,5μm), derme (183,1±44,0μm vs. 258,2±22,9μm), pele total (211,8±46,0μm vs. 290,3±23,7μm) e pericôndrio (27,6±6,1μm vs. 10,5±1,8μm). Além disso, um número maior de células epidérmicas (61,7±15,2 vs. 24,8±7,6) e condrócitos (32,7±9,0 vs. 27,5±4,7) foram observados em cutias, enquanto em preás um maior número de melanócitos (12,6±4,7 vs. 29,9±6,2), queratinócitos (14,7±4,2 vs. 29,8±7,6) e fibroblastos (103,6±24,7 vs. 112,2±11,3) foram evidenciados. Ainda, em preás, uma maior porcentagem de fibras colágenas e da atividade proliferativa foram observadas quando comparadas a pele de cutias. Portanto, existem diferenças entre cutias e preás para pele e cartilagem do pavilhão auricular, exigindo desta forma um estabelecimento de protocolos de criopreservação específica para cada uma destas espécies.(AU)

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)

Melanin bleaching with potassium permanganate for melanocytic lesions diagnosis in veterinary medicine / Despigmentação de melanócitos com permanganato de potássio para diagnóstico de lesões melanocíticas na medicina veterinária

The aim of this study was to microscopically re-evaluate the melanocytic lesions diagnoses established by the Animal Pathology Laboratory of the Federal University of Uberlândia, in the state of Minas Gerais, Brazil, over a period of eleven years; in addition, to perform a comparative analysis between the conventional histopathological (CH) method and the use of the melanin bleaching (MB) technique with potassium permanganate, sulfuric acid, and oxalic acid solutions. The results of the MB method presented a disagreement in 24.32% of the diagnosis previously by CH, with low agreement (61.0%) and low Kappa coefficient (0.2267). Melanoma was the most frequent lesion, more frequent in elderly and non-breed female dogs. The most frequent melanoma location was in the cutaneous tissue. The presence or absence of a pagetoid spread in cutaneous samples, distribution of melanin, pattern of cell layout, cell morphology, degree of cellular atypia, and the number of mitoses verified after MB were the most important criteria to confirm the diagnosis of malignancy or benignity of the lesions. Evaluating pathologists considered MB to be essential for the majority of diagnoses and an efficient complementary method for the diagnosis of melanocytic lesions, even in cases with a moderate degree of pigmentation.(AU)

Este estudo objetivou reavaliar microscopicamente os diagnósticos de lesões melanocíticas estabelecidos pelo setor de Patologia Animal da Universidade Federal de Uberlândia, em um período de 11 anos, e, com base nesse levantamento, realizar uma análise comparativa entre o método histopatológico convencional (HC) e o método de despigmentação de melanócitos (DM) com permanganato de potássio, ácido sulfúrico e ácido oxálico. A DM revelou discordância em 24,32% dos diagnósticos previamente estabelecidos por HC, apresentando baixa concordância (61,0%) e baixo valor de coeficiente Kappa (0,2267). A alteração mais frequente foi o melanoma, com maior ocorrência em cadelas idosas sem raça definida (SRD). A localização mais frequente dos melanomas foi cutânea. A presença ou ausência de disseminação pagetoide nos casos cutâneos, a forma de distribuição da melanina, o padrão de disposição das células, a morfologia celular, o grau de atipia celular e a quantidade de mitoses verificada após a despigmentação foram critérios de elevada importância para firmar o diagnóstico quanto à malignidade ou benignidade da lesão. A despigmentação foi considerada pelos patologistas avaliadores como essencial para o diagnóstico na maioria dos casos, o que leva a concluir que ela constitui um método complementar eficiente no diagnóstico das lesões melanocíticas, mesmo em casos com grau moderado de pigmentação.(AU)

Melanin bleaching with potassium permanganate for melanocytic lesions diagnosis in veterinary medicine / Despigmentação de melanócitos com permanganato de potássio para diagnóstico de lesões melanocíticas na medicina veterinária

The aim of this study was to microscopically re-evaluate the melanocytic lesions diagnoses established by the Animal Pathology Laboratory of the Federal University of Uberlândia, in the state of Minas Gerais, Brazil, over a period of eleven years; in addition, to perform a comparative analysis between the conventional histopathological (CH) method and the use of the melanin bleaching (MB) technique with potassium permanganate, sulfuric acid, and oxalic acid solutions. The results of the MB method presented a disagreement in 24.32% of the diagnosis previously by CH, with low agreement (61.0%) and low Kappa coefficient (0.2267). Melanoma was the most frequent lesion, more frequent in elderly and non-breed female dogs. The most frequent melanoma location was in the cutaneous tissue. The presence or absence of a pagetoid spread in cutaneous samples, distribution of melanin, pattern of cell layout, cell morphology, degree of cellular atypia, and the number of mitoses verified after MB were the most important criteria to confirm the diagnosis of malignancy or benignity of the lesions. Evaluating pathologists considered MB to be essential for the majority of diagnoses and an efficient complementary method for the diagnosis of melanocytic lesions, even in cases with a moderate degree of pigmentation.(AU)

Este estudo objetivou reavaliar microscopicamente os diagnósticos de lesões melanocíticas estabelecidos pelo setor de Patologia Animal da Universidade Federal de Uberlândia, em um período de 11 anos, e, com base nesse levantamento, realizar uma análise comparativa entre o método histopatológico convencional (HC) e o método de despigmentação de melanócitos (DM) com permanganato de potássio, ácido sulfúrico e ácido oxálico. A DM revelou discordância em 24,32% dos diagnósticos previamente estabelecidos por HC, apresentando baixa concordância (61,0%) e baixo valor de coeficiente Kappa (0,2267). A alteração mais frequente foi o melanoma, com maior ocorrência em cadelas idosas sem raça definida (SRD). A localização mais frequente dos melanomas foi cutânea. A presença ou ausência de disseminação pagetoide nos casos cutâneos, a forma de distribuição da melanina, o padrão de disposição das células, a morfologia celular, o grau de atipia celular e a quantidade de mitoses verificada após a despigmentação foram critérios de elevada importância para firmar o diagnóstico quanto à malignidade ou benignidade da lesão. A despigmentação foi considerada pelos patologistas avaliadores como essencial para o diagnóstico na maioria dos casos, o que leva a concluir que ela constitui um método complementar eficiente no diagnóstico das lesões melanocíticas, mesmo em casos com grau moderado de pigmentação.(AU)

Recurrent laryngeal neuropathy secondary to nerve compression by melanomas - case report / Neuropatia laríngea recorrente secundária à compressão por melanomas - relato de caso

Recurrent laryngeal neuropathy (RLN) etiology can be acquired, iatrogenic or idiopathic. There are no previous reports of RLN caused by recurrent laryngeal nerve compression by melanomas. This report describes a horse presenting severe dyspnea and progressive weight loss. Physical exam demonstrated tachycardia, tachypnea, inspiratory dyspnea at rest, neck extension and mydriasis. Temporary tracheotomy was performed and videoendoscopic examination diagnosed grade IV laryngeal paralysis. The animal came suddenly to death by suppurative bacterial pneumonia. At necropsy, it was possible to observe multiple melanotic epithelioid melanoma nodules compressing the recurrent laryngeal nerve, alongside with lung and parotid metastasis. This finding emphasizes the importance of establishing a differential diagnosis for tumor mass compression in the etiology of RLN, especially melanomas in gray horses, with or without cutaneous manifestations of masses.(AU)

A neuropatia laríngea recorrente (NLR) pode apresentar etiologia adquirida, iatrogênica ou idiopática. Não há relatos prévios da ocorrência da NLR causada pela compressão do nervo laríngeo recorrente por melanomas. Este relato descreve um equino apresentando dispneia grave e perda de peso progressiva. O exame físico demonstrou taquicardia, taquipneia, dispneia inspiratória em repouso, extensão do pescoço e midríase. Foi realizada traqueotomia temporária e exame videoendoscópico, mediante o qual se diagnosticou paralisia laríngea grau IV. O animal veio a óbito por pneumonia bacteriana supurativa. Na necropsia, foi possível observar múltiplos nódulos de melanoma epitelioide amelanótico comprimindo o nervo laríngeo recorrente, juntamente com metástases pulmonares e parotídeas. Este achado enfatiza a importância de estabelecer um diagnóstico diferencial nos casos de NLR, pensando-se na compressão nervosa por massas tumorais, especialmente melanomas em cavalos tordilhos, com ou sem manifestações cutâneas de massas.(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)

Recurrent laryngeal neuropathy secondary to nerve compression by melanomas - case report / Neuropatia laríngea recorrente secundária à compressão por melanomas - relato de caso

Recurrent laryngeal neuropathy (RLN) etiology can be acquired, iatrogenic or idiopathic. There are no previous reports of RLN caused by recurrent laryngeal nerve compression by melanomas. This report describes a horse presenting severe dyspnea and progressive weight loss. Physical exam demonstrated tachycardia, tachypnea, inspiratory dyspnea at rest, neck extension and mydriasis. Temporary tracheotomy was performed and videoendoscopic examination diagnosed grade IV laryngeal paralysis. The animal came suddenly to death by suppurative bacterial pneumonia. At necropsy, it was possible to observe multiple melanotic epithelioid melanoma nodules compressing the recurrent laryngeal nerve, alongside with lung and parotid metastasis. This finding emphasizes the importance of establishing a differential diagnosis for tumor mass compression in the etiology of RLN, especially melanomas in gray horses, with or without cutaneous manifestations of masses.(AU)

A neuropatia laríngea recorrente (NLR) pode apresentar etiologia adquirida, iatrogênica ou idiopática. Não há relatos prévios da ocorrência da NLR causada pela compressão do nervo laríngeo recorrente por melanomas. Este relato descreve um equino apresentando dispneia grave e perda de peso progressiva. O exame físico demonstrou taquicardia, taquipneia, dispneia inspiratória em repouso, extensão do pescoço e midríase. Foi realizada traqueotomia temporária e exame videoendoscópico, mediante o qual se diagnosticou paralisia laríngea grau IV. O animal veio a óbito por pneumonia bacteriana supurativa. Na necropsia, foi possível observar múltiplos nódulos de melanoma epitelioide amelanótico comprimindo o nervo laríngeo recorrente, juntamente com metástases pulmonares e parotídeas. Este achado enfatiza a importância de estabelecer um diagnóstico diferencial nos casos de NLR, pensando-se na compressão nervosa por massas tumorais, especialmente melanomas em cavalos tordilhos, com ou sem manifestações cutâneas de massas.(AU)

Melanoma anaplásico em equino de pelagem tordilha com metástase em osso e músculo / Anaplasic melanoma in equine of hair tissue with metastase in bone and muscle

Melanomas são neoplasias cutâneas, com origem em melanócitos. Estes neoplasmas são denominados como lesões melanocíticas e são classificados como nevo melanocítico, melanoma anaplásico e melanoma dérmico. Em equinos são mais frequentes em animais de pelagem tordilha. O objetivo deste trabalho foi relatar um caso de melanoma anaplásico, em um equino de pelagem tordilha encaminhado ao Laboratório Regional de Diagnóstico (LRD), da Faculdade de Veterinária da Universidade Federal de Pelotas (UFPel). No exame externo do cadáver foram observadas massas enegrecidas, sólidas, multilobuladas na região ventral da cauda, períneo e lábio superior. Na necropsia, foram observadas massas com as mesmas características nos linfonodos, músculos dos membros posteriores e no côndilo do osso occipital. Na avaliação histopatológica, de todos os tecidos, observou-se a proliferação de células com núcleos arredondados e abundante citoplasma, contendo grande quantidade de grânulos de melanina. Mitoses eram frequentes e havia acentuado pleomorfismo celular. Com base nos achados macroscópicos e microscópicos foi diagnosticado melanoma anaplásico.

Melanomas are cutaneous neoplasms, originating in melanocytes. These neoplasms are referred to as melanocytic lesions, and are classified as melanocytic nevus, anaplastic melanoma and dermal melanoma. In equines, they are more frequent in animals of tordilha coat. The objective of this study was to report a case of anaplastic melanoma in a tordilha fur horse referred to the Regional Diagnostic Laboratory of the Veterinary School of the Federal University of Pelotas. In the external examination of the cadaver, blackened, solid masses, multilobulated in the ventral region of the tail, perineum and upper lip were observed. At necropsy, there were masses with the same characteristics in lymph nodes, muscles of the hind limbs and in the condyle of the occipital bone. Histologically it was observed in all tissues, proliferation of cells with rounded nuclei, and abundant cytoplasm, containing large amount of melanin granules. Mitoses were frequent and there was marked cellular pleomorphism. Based on macroscopic and microscopic findings, anaplastic melanoma was diagnosed.

Melanoma anaplásico em equino de pelagem tordilha com metástase em osso e músculo / Anaplasic melanoma in equine of hair tissue with metastase in bone and muscle

Melanomas são neoplasias cutâneas, com origem em melanócitos. Estes neoplasmas são denominados como lesões melanocíticas e são classificados como nevo melanocítico, melanoma anaplásico e melanoma dérmico. Em equinos são mais frequentes em animais de pelagem tordilha. O objetivo deste trabalho foi relatar um caso de melanoma anaplásico, em um equino de pelagem tordilha encaminhado ao Laboratório Regional de Diagnóstico (LRD), da Faculdade de Veterinária da Universidade Federal de Pelotas (UFPel). No exame externo do cadáver foram observadas massas enegrecidas, sólidas, multilobuladas na região ventral da cauda, períneo e lábio superior. Na necropsia, foram observadas massas com as mesmas características nos linfonodos, músculos dos membros posteriores e no côndilo do osso occipital. Na avaliação histopatológica, de todos os tecidos, observou-se a proliferação de células com núcleos arredondados e abundante citoplasma, contendo grande quantidade de grânulos de melanina. Mitoses eram frequentes e havia acentuado pleomorfismo celular. Com base nos achados macroscópicos e microscópicos foi diagnosticado melanoma anaplásico.(AU)

Melanomas are cutaneous neoplasms, originating in melanocytes. These neoplasms are referred to as melanocytic lesions, and are classified as melanocytic nevus, anaplastic melanoma and dermal melanoma. In equines, they are more frequent in animals of tordilha coat. The objective of this study was to report a case of anaplastic melanoma in a tordilha fur horse referred to the Regional Diagnostic Laboratory of the Veterinary School of the Federal University of Pelotas. In the external examination of the cadaver, blackened, solid masses, multilobulated in the ventral region of the tail, perineum and upper lip were observed. At necropsy, there were masses with the same characteristics in lymph nodes, muscles of the hind limbs and in the condyle of the occipital bone. Histologically it was observed in all tissues, proliferation of cells with rounded nuclei, and abundant cytoplasm, containing large amount of melanin granules. Mitoses were frequent and there was marked cellular pleomorphism. Based on macroscopic and microscopic findings, anaplastic melanoma was diagnosed.(AU)

Remoção cirúrgica de melanoma de terceira pálpebra em equino / Surgical removal of melanoma in the third eyelid in equine

O melanoma é uma neoplasia maligna de melanócitos, os quais produzem a melanina responsável pela pigmentação da pele, descrito em várias espécies animais e em seres humanos. Em equinos, esse tipo tumoral representa grande parte dos comprometimentos cutâneos, principalmente em animais de pelagem tordilha; porém não se observa predileção racial e sexual, sendo a idade considerada um agravante na malignidade. Esta afecção acomete principalmente as regiões de cauda, períneo, orelhas e olhos, e ocasionalmente se desenvolvem em órgãos genitais; sendo que o curso clínico varia desde a invasão de órgãos até a disseminação metastática. Caracterizam-se por lesões firmes, nodulares, únicas ou múltiplas, de tamanhos e coloração variados, infiltrativas, podendo ocorrer ulcerações. Os sinais clínicos demonstrados pelos pacientes acometidos são variáveis, dependendo da localização tumoral. Em animais, o diagnóstico de melanoma está relacionado a um prognóstico desfavorável, pois, em geral, o tumor é detectado tardiamente, quando já houve infiltração local ou formação de metástases. Este trabalho tem como objetivo relatar um caso relacionado a melanoma de terceira pálpebra em um equino macho, com 13 anos de idade, raça Puro Sangue Lusitano (PSL), pelagem tordilha. O animal apresentava nódulos de tamanhos consideráveis na terceira pálpebra do olho direito, de coloração enegrecida, sendo submetido a procedimento cirúrgico para a remoção total do mesmo. O animal foi submetido a um protocolo pós-cirúrgico com antibioticoterapia local na forma de colírio (Ciprofloxacina 0,3mg ou 02 gotas), quatro vezes ao dia, durante dez dias e também sistêmica (Benzilpenicilina G Procaína 4000UI/Kg/PV) por via intramuscular, uma vez ao dia, durante cinco dias...

Melanoma is a malignant neoplasm of melanocytes which produce melanin, responsible for skin pigmentation, described in various animal species and in humans. In equines, this tumor type represents a large part of the mainly in fur animals; but there is no racial and sexual predilection, and age is considered an aggravating factor in malignancy. This condition mainly affects the tail, perineum, auricular and ocular regions and occasionally develops in the genital organs; and the clinical course varies from invasion of organs to metastatic dissemination. It is characterized by firm, nodular, single or multiple lesions of varying infiltrative sizes and staining, and ulcerations may occur. The clinical signs demonstrated by the affected patients are variable, depending on the tumor location. In animals, the diagnosis of melanoma is related to an unfavorable prognosis, since, in general, the tumor is detected late, when there has been local infiltration or formation of metastases. The aim of this study is to report a case related to third eyelid melanoma in a 13 year - old male Purebred Lusitano (PSL) equine breed. The animal presented nodules of considerable size in the third eyelid of the right eye, of blackened color, being submitted to surgical procedure for the total removal of the same one. The animal was submitted to a post-surgical protocol with local antibiotic therapy in the form of eye drops (Ciprofloxacin 0.3mg or 2 drops), four times a day for ten days and also systemic (Benzylpenicillin G Procaine 4000UI/Kg/PV) intramuscularly once daily for five days. As an anti-inflammatory protocol, it was used topically, eye drops (Flurbiprofen Sodium 0.03mg or 2 drops), four times a day for ten days and intravenously (Fenilbutazone 4.0mg/Kg/PV), once a day during five days, responding satisfactorily to the treatment.

Remoção cirúrgica de melanoma de terceira pálpebra em equino / Surgical removal of melanoma in the third eyelid in equine

O melanoma é uma neoplasia maligna de melanócitos, os quais produzem a melanina responsável pela pigmentação da pele, descrito em várias espécies animais e em seres humanos. Em equinos, esse tipo tumoral representa grande parte dos comprometimentos cutâneos, principalmente em animais de pelagem tordilha; porém não se observa predileção racial e sexual, sendo a idade considerada um agravante na malignidade. Esta afecção acomete principalmente as regiões de cauda, períneo, orelhas e olhos, e ocasionalmente se desenvolvem em órgãos genitais; sendo que o curso clínico varia desde a invasão de órgãos até a disseminação metastática. Caracterizam-se por lesões firmes, nodulares, únicas ou múltiplas, de tamanhos e coloração variados, infiltrativas, podendo ocorrer ulcerações. Os sinais clínicos demonstrados pelos pacientes acometidos são variáveis, dependendo da localização tumoral. Em animais, o diagnóstico de melanoma está relacionado a um prognóstico desfavorável, pois, em geral, o tumor é detectado tardiamente, quando já houve infiltração local ou formação de metástases. Este trabalho tem como objetivo relatar um caso relacionado a melanoma de terceira pálpebra em um equino macho, com 13 anos de idade, raça Puro Sangue Lusitano (PSL), pelagem tordilha. O animal apresentava nódulos de tamanhos consideráveis na terceira pálpebra do olho direito, de coloração enegrecida, sendo submetido a procedimento cirúrgico para a remoção total do mesmo. O animal foi submetido a um protocolo pós-cirúrgico com antibioticoterapia local na forma de colírio (Ciprofloxacina 0,3mg ou 02 gotas), quatro vezes ao dia, durante dez dias e também sistêmica (Benzilpenicilina G Procaína 4000UI/Kg/PV) por via intramuscular, uma vez ao dia, durante cinco dias...(AU)

Melanoma is a malignant neoplasm of melanocytes which produce melanin, responsible for skin pigmentation, described in various animal species and in humans. In equines, this tumor type represents a large part of the mainly in fur animals; but there is no racial and sexual predilection, and age is considered an aggravating factor in malignancy. This condition mainly affects the tail, perineum, auricular and ocular regions and occasionally develops in the genital organs; and the clinical course varies from invasion of organs to metastatic dissemination. It is characterized by firm, nodular, single or multiple lesions of varying infiltrative sizes and staining, and ulcerations may occur. The clinical signs demonstrated by the affected patients are variable, depending on the tumor location. In animals, the diagnosis of melanoma is related to an unfavorable prognosis, since, in general, the tumor is detected late, when there has been local infiltration or formation of metastases. The aim of this study is to report a case related to third eyelid melanoma in a 13 year - old male Purebred Lusitano (PSL) equine breed. The animal presented nodules of considerable size in the third eyelid of the right eye, of blackened color, being submitted to surgical procedure for the total removal of the same one. The animal was submitted to a post-surgical protocol with local antibiotic therapy in the form of eye drops (Ciprofloxacin 0.3mg or 2 drops), four times a day for ten days and also systemic (Benzylpenicillin G Procaine 4000UI/Kg/PV) intramuscularly once daily for five days. As an anti-inflammatory protocol, it was used topically, eye drops (Flurbiprofen Sodium 0.03mg or 2 drops), four times a day for ten days and intravenously (Fenilbutazone 4.0mg/Kg/PV), once a day during five days, responding satisfactorily to the treatment.(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)