Cytological grading of canine mast cell tumors: correlation with histologic grading and survival time / Graduação citológica de mastocitomas caninos: correlação com graduação histológica e sobrevida

ABSTRACT: Mast cell tumors are one of the most common neoplasia in dogs and cytopathology and/or histopathology examinations are used for diagnosis. Histologic grading is considered the gold standard test to predict the prognosis of this neoplasia. However, studies have been conducted using the cytological grading system to provide similar information in a faster, less invasive, and more accessible way. This study aimed to investigate cytological graduation and correlate it with histological grading and the survival time of dogs diagnosed with cutaneous mast cell tumors at the Veterinary Hospital of "Universidade Federal de Uberlândia" over five years. For that, cytological and histological slides from 72 animals were reviewed. The statistical methods used were the kappa test for agreement between grading systems, the Kaplan-Meier for survival time, Cox regression for comparison of cytological and histological grades and survival time. The cytological grading when compared to the two-tier histologic grading, high and low grades, had a moderate agreement (kappa 0.566). When the correlation between survival time and the cytological grade was evaluated, there was a higher death rate in the group with high-grade mast cell tumors compared to low grade, pointing to a correlation between survival time and cytological grade (p=0.009). In conclusion, the cytological grade is useful to treatment planning and providing prognostic information that precedes tumor removal, showing a good correlation with the two-tier histologic grading and with the survival time of the animals.

RESUMO: O mastocitoma é uma das neoplasias cutâneas mais comum nos cães e os exames citopatológicos e/ou histopatológicos são utilizados para diagnóstico. A graduação histológica é considerada padrão ouro para prever o prognóstico dessa neoplasia. Contudo, estudos têm sido realizados visando utilizar graduação citológica para fornecer informações semelhantes de maneira rápida, menos invasiva e mais acessível. Esse trabalho objetivou realizar graduação citológica e correlacionar com as graduações histológicas e com a sobrevida de cães diagnosticados com mastocitoma cutâneo no Hospital Veterinário da Universidade Federal de Uberlândia durante 5 anos. Para isso, lâminas de citologia e histologia de mastocitomas de 72 animais foram revisadas. Os métodos estatísticos utilizados foram teste kappa para concordância entre os sistemas de graduação, método Kaplan-Meier para tempo de sobrevida dos animais, e análise pela regressão de Cox para comparação do grau citológico e grau histológico e o tempo de sobrevida global. A graduação citológica quando comparada com a histológica de dois níveis, alto grau e baixo grau, obteve uma concordância moderada (kappa 0,566). Na avaliação da correlação entre sobrevida e grau citológico, houve maior taxa de óbito no grupo de cães com mastocitoma de alto grau, comparado aos de baixo grau, sendo observada correlação entre a sobrevida e o grau citológico (p=0,009). Esse estudo concluiu que o grau citológico é útil para o planejamento do tratamento e para fornecer informações prognósticas que antecedem a exérese do tumor, tendo boa correlação com a graduação histológica de dois níveis e com a sobrevida dos animais.

Epididymal primary mast cell tumor in a dog

Background: In the literature, there are a few descriptions of epididymis neoplasia in domestic animals, especially considering primary tumors. In the few reports found in literature, the lesions were a consequence of the invasion of testicular or paratesticular neoplasia, as a papillar carcinoma in a dog's and a bull's epididymis, and mesenchymal tumors - fibrome/ fibrosarcoma, leiomyoma/leiosarcome. On the other hand, mast cell tumors are the second most prevalent neoplasia in dogs in Brazil, affecting especially the skin. The aim of this report is to describe for the first time a low malignancy mast cell tumor in a mixed-breed dog's epididymis, without metastasis or recurrence in a 2-year follow-up period. Case: A 10-year-old male mixed-breed dog was presented for pre-surgical evaluation for elective orchiectomy. In the physical examination, an increase in the volume of approximately 2 cm with an irregular appearance was identified on palpation in the cranial pole of the left testis. In the trans surgical period, an increase in testicular volume (4 cm long x 2 cm wide) was observed, with a firm consistency in the region of the vas deferens with macroscopic changes in the region. The testis was sectioned, and the fragments were sent for histopathological evaluation in 10% buffered formaldehyde. There was a fairly cellular circumscribed neoplastic infiltrate, distributed in a sheet and separated by fibrovascular stroma, and rounded neoplastic cells with a moderate amount of basophilic cytoplasmic granulation, and discrete anisocytosis and anisokaryosis. The nuclei were rounded with vesicular chromatin with 1 or 2 distinct nucleoli. No mitosis figures were observed in 10 high power fields (400x). Few eosinophils were distributed throughout the neoplastic cell population. Immunohistochemistry demonstrated immunostaining for KIT protein with perimembranous staining in 95% of neoplastic mast cells, giving a KIT 1 pattern. There was no positive nuclear staining for Ki67 in any cell of the histological sections examined. A grade II mast cell tumor (low grade of malignancy) was diagnosed. After diagnosis, the animal underwent radiographic evaluation of the chest and abdominal ultrasound, and a new physical inspection in search of nodules, plaques, skin lesions, or subcutaneous masses. There were no metastases in the thorax and abdominal cavity, nor physical alterations, and it can be inferred that the epididymis was the primary site of the mast cell tumor. After 2 years of orchiectomy, there were no recurrences, and no chemotherapy treatment was performed. Discussion: Extracutaneous mast cell tumors are uncommon in animals, but have been reported in oral and nasal mucosa, nasopharynx, larynx, trachea, intestine, visceral lymph nodes, spleen, liver, spinal cord, intestine, ureter, conjunctiva, lung and more recently in tear gland of the third eyelid. However, in the authors' assessment, this is the first description of mast cell tumor in the epididymis in dogs. The diagnosis was established by histopathological examination, which revealed a grade II epididymal mast cell tumor and immunohistochemical evaluation (KIT and Ki-67) as being of low aggressiveness. The diagnosis of a primary tumor was confirmed since the staging was established after the histopathological diagnosis, involving chest radiography, abdominal ultrasound, cutaneous evaluation in search of nodules, plaques, cutaneous and subcutaneous lesions, and did not reveal other abnormalities or metastases not identified in the preoperative evaluation. In addition, immunostaining with KIT and Ki-67 reaffirmed the low degree of malignancy and the potential for metastases, which can be observed by the asymptomatic follow-up of the patient 2 years after the surgical excision.

Mutations of the c-KIT gene in canine mast cell tumors and respective nodal metastases classified according to mast cell infiltration / Mutações no gene c-KIT em mastocitomas caninos e respectivas metástases nodais classificados segundo a infiltração de mastócitos

The molecular background of canine mast cell tumors (MCT) has been extensively investigated; however, the dynamic molecular changes that occur during carcinogenesis and metastasis are not fully understood. This study aimed to evaluate the incidence of mutations in the c-KIT proto-oncogene in canine MCTs and relative draining regional lymph nodes. Suspected or confirmed lymph node metastasis was classified accordingly to the HN Weishaar classification. The study included 34 dogs diagnosed with MCT; 19 patients were enrolled prospectively. These dogs had the primary MCT and regional lymph node resected and analyzed simultaneously. The second group was evaluated retrospectively and included fifteen patients resectioning the primary MCT without evaluation of regional lymph node. Analyzes of c-KIT mutation were performed for all primary MCTs and, in the first group, compared between primary MCT and HN-classified metastasis. Internal tandem duplications (ITD) in exon 11 of the c-KIT gene were detected in 20% of patients. Ten of the nineteen patients (52%) in the first group presented mast cell infiltration in the regional lymph node, and ITD in exon 11 of the c-KIT gene was detected in five and two dogs from Groups 1 and 2, respectively. ITD c-KIT mutations are common in canine MCT and may be found in the draining lymph node metastases/mast cell infiltrates in the absence of mutation of the primary tumor. Evaluation of c-KIT mutation in the primary tumor and metastases may be informative for defining both prognosis and therapeutic options in MCT cases.

O perfil molecular do mastocitoma (MCT) tem sido bastante investigado, no entanto as dinâmicas moleculares que ocorrem durante a carcinogênese e metástase desta neoplasia não estão bem esclarecidas. O objetivo desse estudo foi avaliar a incidência de mutações no proto-oncogene c-KIT em MCTs caninos e respectivos linfonodos regionais. Os casos suspeitos ou confirmados de metástase para os linfonodos, foram classificados de acordo com a classificação HN de Weishaar. O estudo incluiu 34 cães diagnosticados com MCT e, desses, 19 pacientes foram avaliados de maneira prospectiva, em que o tumor primário e o linfonodo regional foram ressecados e analisados simultaneamente. O segundo grupo foi avaliado retrospectivamente e incluiu quinze pacientes que tiveram ressecção do MCT primário sem avaliação de linfonodo regional. A análise da mutação c-KIT foi realizada para todos os MCTs primários e, no primeiro grupo, comparados entre MCT primário e metástase classificada pelo sistema HN. Duplicações internas em tandem (DIT), no exon 11 do gene c-KIT, foram detectadas em um total de 20% dos pacientes. Dez dos dezenove pacientes (52%) do primeiro grupo apresentavam infiltração de mastócitos no linfonodo regional, e DIT no exon 11 do gene c-KIT foram identificadas em cinco e dois cães dos Grupos 1 e 2, respectivamente. Mutações do tipo DIT no gene c-KIT são comuns no MCT canino e podem estar presentes nas metástases/infiltrados de mastócitos na ausência de mutação do tumor primário. A avaliação da mutação no gene c-KIT no tumor primário e metástases pode ser informativa para definir tanto o prognóstico quanto as opções terapêuticas em casos de MCT.

Mastocitoma cutâneo canino após mastocitose acidental induzida por opioide: Relato de caso / Canine cutaneous mastocytoma after accidental opioid-induced mastocytosis: Case report

A aproximação entre petse tutores está cada vez mais presente na rotina atual das residências familiares. Essa aproximação aumenta a observação de quaisquer alterações físicas ou comportamentais dos animais levando-o a buscar um médico veterinário quando necessário. O papel do clínico, oncologista e do patologista veterinário vem a ser de extrema importância para detecção das neoplasias em suas fases iniciais. A utilização dos meios de diagnósticos complementares para os casos de neoplasias é de fundamental importância para ter ciência do prognóstico do animal e de qual tratamento será o melhor tratamento para os casos abordados. O mastocitoma é a neoplasia cutânea mais frequente do cão, é uma neoplasia maligna e sua etiologia é pouco compreendida. Independente do sexo, atingem machos e fêmeas, porém se apresentam de forma mais agressiva em machos. O diagnóstico, geralmente é estabelecido por meio de exames complementares, associados aos sinaisclínicos, devendo sempre prezar pelo diagnóstico precoce para que haja maior êxito no tratamento.O exame citológico para o diagnóstico de mastocitoma é um dos métodos mais eficientes e de baixo custo, sendo complementado pelo exame histopatológico para agraduação de malignidade e estadiamento da doença. Preconiza-se a associação da cirurgia com o tratamento quimioterápico com terapia antiblástica e eletroquimioterapia para um melhor prognóstico. O objetivo deste trabalho foi relatar um caso de mastocitoma cutâneo após um erro primário de manejo clinico, em um canino, macho, nove anos, da raça American Pitbull Terrier, trazendo sua complexidade e bases dos meios de diagnóstico(AU)

The approximation between pets and tutors is increasingly present in the current routine of family homes. This approach increases the observation of physical or behavioral changes in animals, leading them to seek a veterinarian when necessary. The role of the clinician, oncologist and veterinary pathologist is extremely important for the detection of neoplasms in their early stages. The use of complementary diagnostic means for cases of neoplasms is of fundamental importance to be aware of the animal's prognosis and which treatment will be the best treatment for the cases examined. Mastocytoma is the most frequent skin neoplasm in dogs, it is a malignant neoplasm and its etiology is poorly understood. Regardless of gender, they affect males and females, but are more aggressive in males. The diagnosis is usually established through complementary exams, associated with clinical signs. Cytological examination for the diagnosis of mast cell tumor is an inexpensive method and one of the most efficient methods, being complemented by histopathological examination for its evolution of malignancy and disease staging, recommended the association of surgery with chemotherapy treatment with antiblastic therapy and electrochemotherapy for better prognoses. The aim of this study was to report a case of cutaneous mastocytoma after a primary error in clinical management, in a canine, male, nine years old, of the American Pitbull Terrier breed, bringing its complexity and bases of the means of diagnosis(AU)

Canine mammary neoplasms - evaluation of tumor microenvironment

Background: The tumor microenvironment is an important target of studies in different types of neoplasms. Understanding the role of general components such as immune, vascular and fibroblastic cells has the objective of contributing to prognosis and treatment. The aim of this study was to evaluate the relationship between mast cells and angiogenesis in benign and malignant mammary neoplasms by investigating the role of degranulation and microlocation of mast cells and neoformed vessels in canine mammary neoplasms. Materials, Methods & Results: Mammary glands (n = 122) from 50 female dogs submitted to mastectomy without chemotherapy were evaluated and categorized into 3 groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. To evaluate the MCD (mast cell density) and angiogenesis, Toluidine Blue (0.1%) and Gomori’s Trichrome techniques were performed and adapted from previous studies. Photomicrographs of 10 hotspot areas on a 40x objective lens of the mammary glands and lymph nodes were captured to assess MCD and angiogenesis. In the absence of these areas, random fields were captured. For the mammary glands of the malignant and benign groups, 20 fields were analyzed, as the analysis considered the microlocation (peritumoral and intratumoral). Counting was performed manually using ImageJ software version 1.42q by 2 observers. The statistical analysis were performed using SPSS software version 19.0. The most frequent histological type in the malignant group was carcinoma in mixed tumor (68.42%; 39/57) and in the benign group was benign mixed tumor (57.89%; 11/19). Female dogs without breed pattern were more frequently affected represented 70% of the animals and the mean age was 9 years and 8 months ± 3 years and 1 month...

Canine mammary neoplasms - evaluation of tumor microenvironment

Background: The tumor microenvironment is an important target of studies in different types of neoplasms. Understanding the role of general components such as immune, vascular and fibroblastic cells has the objective of contributing to prognosis and treatment. The aim of this study was to evaluate the relationship between mast cells and angiogenesis in benign and malignant mammary neoplasms by investigating the role of degranulation and microlocation of mast cells and neoformed vessels in canine mammary neoplasms. Materials, Methods & Results: Mammary glands (n = 122) from 50 female dogs submitted to mastectomy without chemotherapy were evaluated and categorized into 3 groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. To evaluate the MCD (mast cell density) and angiogenesis, Toluidine Blue (0.1%) and Gomoris Trichrome techniques were performed and adapted from previous studies. Photomicrographs of 10 hotspot areas on a 40x objective lens of the mammary glands and lymph nodes were captured to assess MCD and angiogenesis. In the absence of these areas, random fields were captured. For the mammary glands of the malignant and benign groups, 20 fields were analyzed, as the analysis considered the microlocation (peritumoral and intratumoral). Counting was performed manually using ImageJ software version 1.42q by 2 observers. The statistical analysis were performed using SPSS software version 19.0. The most frequent histological type in the malignant group was carcinoma in mixed tumor (68.42%; 39/57) and in the benign group was benign mixed tumor (57.89%; 11/19). Female dogs without breed pattern were more frequently affected represented 70% of the animals and the mean age was 9 years and 8 months ± 3 years and 1 month...(AU)

Abordagem diagnóstica de mastocitoma cutâneo metastático em canino / Diagnostic approach of metastatic cutaneous mastocytoma in dog

O mastocitoma é uma das neoplasias cutâneas mais comuns que acometem cães. O diagnóstico da doença é baseado em aspectos clínicos e laboratoriais, sendo a citologia e a histopatologia os métodos de eleição. Diante disso, o objetivo deste estudo é relatar a importância da ampla abordagem diagnóstica de mastocitoma cutâneo metastático em uma fêmea canina castrada, atendida no Hospital Veterinário da Universidade Estadual do Ceará, com uma neoformação em membro compatível com mastocitoma. O estadiamento da paciente foi feito através de exames laboratoriais de hemograma completo, e citologia aspirativa de linfonodo regional e medula óssea, que evidenciaram a presença de focos de metástase; bem como do exame de ultrassom abdominal, que evidenciou alterações no parênquima hepático e linfoadenomegalia ilíaco medial direita. Diante das suspeitas, optou-se pela eutanásia da paciente, cujo corpo foi enviado para os exames de necropsia e histopatologia, os quais confirmaram o diagnóstico de mastocitoma cutâneo de alto grau, com metástase em fígado, pulmão, medula e linfonodos. Desta forma pode-se concluir que o mastocitoma cutâneo metastático é uma neoplasia de diagnóstico multifatorial, em que a realização de exames hematológicos associados às análises citológicas, histopatológicas e de imagem são indispensáveis para estabelecer o diagnóstico definitivo para que seja determinada uma melhor conduta terapêutica e prognóstico de pacientes caninos.

Mast cell tumors are one of the most common skin neoplasms that affect dogs. The diagnosis is based on clinical and laboratory aspects, with cytology and histopathology being the preferred methods. Therefore, this study aims to report the importance of the broad diagnostic approach of metastatic cutaneous mastocytoma in a castrated a female dog attended at the Veterinary Hospital of the State University of Ceará, with a neoformation in a member compatible with mast cell tumor. The patient's staging was performed through laboratory tests of complete blood count, aspiration cytology of regional lymph nodes and bone marrow, which showed the presence of focus of metastasis, as well as the abdominal ultrasound examination, which showed changes in the liver parenchymas and right medial iliac lymphadenopathy. Given the suspicions, the patient was euthanized and the body was sent for necropsy and histopathological examination, which confirmed the diagnosis of high-grade cutaneous mast cell tumor, with metastasis in the liver, lung, bone marrow, and lymph nodes. Thus, it can be is concluded that mast cell tumor is a neoplasm of multifactorial diagnosis, where hematological tests associated with cytology, histopathological, and imaging analyses are essential to establish the definitive diagnosis to determine a better therapeutic behavior and prognosis of canine patients.

Mastocitoma cutâneo em uma cadela / Cutaneous mast cell tumor in a bitch

Background: The diagnostic of neoplasia in dogs has risen significantly in the last years and this fact is mostly attributed to the longer life expectancy of these animals, which contributes to a greater chance of exposure to carcinogenic agents. In between the diverse tumors that could compromise skin, the mastocytoma is the third most commonly diagnosed neoplasia. It is characterized by being a form of neoplasia with round cells, these being the mast cells. The objective of the present study consisted in relating a case of cutaneous mastocytoma in a 7-year-old bitch mixed-breed treated at the Veterinary Medical Teaching Hospital of the University of Uberaba (UNIUBE) - Uberaba, MG, Brazil. Case: The bitch initially presented a localized nodule external to the right ear pinna with cytology test suggesting a mastocytoma. The nodule was surgically removed and, posteriorly, an histopatholgy was not requested. After 5 months since the emergence of the nodule and a month after its surgical resection, the tutor noticed the presence of a new growth in the ipsilateral cervical region to the previous nodule. At this moment, the responsible veterinarian decided to refer the animal to an oncologist. During the appointment with the oncologist, alterations such as hyporexia and anemia were related, and the presence of a nodule in the right cervical region measuring 4.5 to 4 cm of diameter was verified. Material for cytologic evaluation of the neoplasia was collected and again the result suggested a mastocytoma. The new tumor was also surgically removed but was then referred to histopathological evaluation for diagnostic confirmation, grading and evaluation of surgical margins. The tumor was classified as an infiltrative subcutaneous mastocytoma presenting, additionally, compromised surgical margins. After its excision, the association with a chemotherapy treatment using a protocol of Vimblastina 2 mg/m², i.v. in unique dosage per section, associated with Predinisona 1 mg/kg, v.o, SID was indicated. Each section was realized with an interval of 7 days in between. Only 2 chemotherapy sessions took place. Because of the worsening of the clinical condition associated with a very weakened animal the veterinarian opted for the euthanasia of the animal. Discussion: The diagnostic of mastocytoma must be realized through the association of cytology and histopathology, in case histopathological evaluation is needed to confirm the obtained cytology result, to grade the tumor and to evaluate the compromising of surgical margins. In this sense, it was observed that the bitch was submitted only to cytology diagnostic when it presented the nodule in the ear pavilion. Yet, at the second approach realized by the oncologist, it was possible to realize adequate diagnose methods. However, the animal was not submitted to clinical staging of the mastocytoma due to the non-authorization of the exam by the tutor. Such measure is very important, as it reflects directly in the treatment and prognostic of the animal. Thus, image exams such as abdominal ultrasonography and chest X-ray should have been realized, as well as cytological and histopathological evaluation of the regional lymph nodes, in order to search for metastasis points in these places. As the data suggests, the importance of clinical staging of animals affected by this neoplasia and the importance of cytological evaluation associated with histopathology for a correct diagnosis, prognosis and mastocytoma treatment is noted. It is emphasized that many times veterinarians face impediment related to requesting all necessary exams coming from tutors, which compromises treatment success.

Association between vitamin D and malignant mammary tumors in obese female dogs

Overweight and obesity are known risk factors that are involved in the development and aggressiveness of breast tumors in women. In situations of obesity, local and systemic inflammation may worsen the prognosis of oncological patients. Moreover, hypovitaminosis D increases the risk of breast tumors in women. In female dogs, low vitamin D levels have been found in cases of lymphoma, osteosarcoma and mast cell tumor. The present study aimed to make correlations between body fat composition and serum 25(OH)D concentration in female dogs with mammary tumors. Two experimental groups were formed: healthy female dogs (n = 12; control group) and female dogs with mammary tumors (n = 11). An analysis on body composition was performed using dual-energy X-ray absorptiometry (DXA) equipment. In the tumor group, multicentric nodules were most prevalent (63,6%), with diameters of up to 8.2 cm. The most frequent histopathological diagnosis was tubular carcinoma (45.5%), and 9.1% presented metastases in axillary lymph nodes. The mean 25(OH)D concentration in the female dogs with mammary tumors (37.6 ng mL-1) was lower than the level in the control group (65.4 ng mL-1). Multivariate statistical analysis showed that elderly female dogs with malignant mammary tumors and high body fat levels presented lower 25(OH)D concentrations than those of the control group. It was concluded that female dogs with higher body adiposity presented mammary tumors of higher aggressivity, and that the higher the fat percentage was in the female dogs with malignant mammary tumors, the lower their vitamin D concentration was.(AU)

Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report / Mastocitoma cutâneo em um cachorro-do-mato vinagre (Speothos venaticus) de cativeiro: aspectos patológicos e imunofenotípicos - relato de caso

A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.(AU)

Um cachorro-vinagre (Speothos venaticus) apresentou um nódulo cutâneo pequeno na região perianal. Histologicamente havia neoplasia cutânea de células redondas e ulcerada, constituída por mastócitos bem diferenciados, com abundantes grânulos citoplasmáticos metacromáticos na coloração de Giemsa e infiltrado eosinofílico difuso. A imuno-histoquímica demonstrou que 30% das células neoplásicas eram positivas para a proteína Kit no citoplasma e na membrana celular. As células foram negativas para MAC e CD3. Menos de 10% das células neoplásicas foram positivas para Ki67. Durante a necropsia, foram identificados outros tumores primários, como adenoma intestinal, adenoma cortical da adrenal e tumor de células intersticiais do testículo.(AU)

Epidemiology of Canine Mast Cell Tumors in Uruguay

We examined in the present study main epidemiological features of canine mast cell tumors in Uruguay, principal breeds of occurrence, age, gender, anatomical distributions, and associated differences of pathological grading. During a three-year period, eighty four out of 405 skin specimens of dogs mainly received at the Veterinary Faculty of Montevideo from private clinics were mast cell tumors. Mix-breed dogs were mostly affected, followed by Labrador Retrievers, Boxers, Pit bulls and Golden Retrievers. Age of patients ranged from 3 to 15 years (median 7.9), and the incidence in females was slightly higher than in males. Tumors were more frequent in the trunk, followed by extremities, scrotum and neck. The majority of specimens were of high malignancy.(AU)

Epidemiology of Canine Mast Cell Tumors in Uruguay

We examined in the present study main epidemiological features of canine mast cell tumors in Uruguay, principal breeds of occurrence, age, gender, anatomical distributions, and associated differences of pathological grading. During a three-year period, eighty four out of 405 skin specimens of dogs mainly received at the Veterinary Faculty of Montevideo from private clinics were mast cell tumors. Mix-breed dogs were mostly affected, followed by Labrador Retrievers, Boxers, Pit bulls and Golden Retrievers. Age of patients ranged from 3 to 15 years (median 7.9), and the incidence in females was slightly higher than in males. Tumors were more frequent in the trunk, followed by extremities, scrotum and neck. The majority of specimens were of high malignancy.

Mastocitoma de alto grau em bolsa testitular em cão / Mast cell tumor high grade in testicular bag in dog

Mast cell tumor is the most common skin tumor in dogs. Due to mast cell proliferation, the affected animals present clinical symptoms compatible with the release of excess histamine granules present inside these cells leading to changes in the gastrointestinal and vascular tracts with the possibility of causing anaphylactic shock. The diagnosis is made by cytopathological analysis and classified by means of histopathology. Treatment is based on staging, surgical exeresis with antineoplastic chemotherapy and drug treatment to inhibit the effects of histamine release. A dog of 14 years old of Boxer breed was attend complaining of nodulation in the testicular bag with a two month evolution. Animal was diagnosed with mast cell tumor. Treatment was instituted by surgical excision and due to the metastatic possibility in regional lymph node, antineoplastic and drug therapy was indicated, which was not successful due of the person responsible non-adherence to the treatment. Mast cell tumor classified as high grade after histopathological analysis. Animal survived for two months after diagnosis of the disease. Due to the high grade of neoplastic presentation and difficulty in treatment, the animal had low survival, corroborating with data described in the literature regarding the poor prognosis of this tumor type.

Mastocitoma de alto grau em bolsa testitular em cão / Mast cell tumor high grade in testicular bag in dog

Mast cell tumor is the most common skin tumor in dogs. Due to mast cell proliferation, the affected animals present clinical symptoms compatible with the release of excess histamine granules present inside these cells leading to changes in the gastrointestinal and vascular tracts with the possibility of causing anaphylactic shock. The diagnosis is made by cytopathological analysis and classified by means of histopathology. Treatment is based on staging, surgical exeresis with antineoplastic chemotherapy and drug treatment to inhibit the effects of histamine release. A dog of 14 years old of Boxer breed was attend complaining of nodulation in the testicular bag with a two month evolution. Animal was diagnosed with mast cell tumor. Treatment was instituted by surgical excision and due to the metastatic possibility in regional lymph node, antineoplastic and drug therapy was indicated, which was not successful due of the person responsible non-adherence to the treatment. Mast cell tumor classified as high grade after histopathological analysis. Animal survived for two months after diagnosis of the disease. Due to the high grade of neoplastic presentation and difficulty in treatment, the animal had low survival, corroborating with data described in the literature regarding the poor prognosis of this tumor type.(AU)

Ampliação de margens em cão com mastocitoma cutâneo: relato de caso / Margins enlargement in dog for cutaneous mastocytoma: case report

Objetiva-se relatar a reintervenção cirúrgica para ampliação de margens em um paciente diagnosticado com mastocitoma cutâneo. Um canino, macho, Bulldog Francês, com 7 anos foi atendido com histórico de retirada de nódulo cutâneo em região abdominal há 15 dias, com diagnóstico histopatológico compatível com mastocitoma grau I e margens cirúrgicas comprometidas. Optou-se então pela realização de um segundo procedimento cirúrgico para ampliação das margens de segurança, o qual foi precedido por planejamento de 5 cm de margens cutâneas e uma camada de fáscia e um plano muscular como margem profunda, juntamente com a linfadenectomia inguinal. Durante o procedimento, foi possível a síntese sem a necessidade do uso de técnicas reconstrutivas, a partir da divulsão do subcutâneo e da utilização do padrão Walking Suture. Não houve intercorrências transoperatórias, e a formação de hematoma foi a única complicação pósoperatória observada. O material foi enviado para análise histopatológica, confirmando mastocitoma cutâneo baixo grau/grau I com margens livres, sem evidências de metástase em linfonodo. Dessa forma, não foram instituídas terapias adjuvantes, e após 320 dias pós-operatórios, o paciente apresentava-se em ótimo estado geral, sem evidências de recidiva ou metástases à distância na radiografia torácica e ultrassonografia abdominal. Conclui-se que a reintervenção cirúrgica pode ser uma alternativa para o tratamento do mastocitoma baixo grau/grau I com margens comprometidas, sendo o diagnóstico histopatológico e o planejamento cirúrgico essenciais para redução de complicações trans e pósoperatórias, aumentando as chances de sucesso e cura do paciente.

The objective is to report the surgical reintervention for enlarging margins in a patient diagnosed with cutaneous mast cell tumor. A canine, male, French Bulldog, 7 years old, was seen with a history of skin nodule removal in the abdominal region 15 days ago, with a histopathological diagnosis compatible with grade I mastocytoma and compromised surgical margins. Then, it was decided to perform a second surgical procedure to expand the safety margins, which was preceded by planning 5 cm of cutaneous margins and a layer of fascia and a muscular plane as a deep margin, in addition to inguinal lymphadenectomy. During the procedure, synthesis was possible without the use of reconstructive techniques, from the subcutaneous divulsion and the use of the Walking Suture pattern. There were no transoperative complications, and hematoma formation was the only postoperative complication observed. The material was sent for histopathological analysis, confirming low-grade cutaneous mastocytoma with free margins and no evidence of lymph node metastasis. Thus, adjuvant therapies were not instituted, and after 320 postoperative days, the patient was in excellent general condition, with no evidence of recurrence or distant metastases on chest radiography and abdominal ultrasound. It is concluded that surgical reintervention can be an alternative for the treatment of low-grade mastocytoma with compromised margins, and that histopathological diagnosis and surgical planning are essential to reduce trans and postoperative complications, increasing the chances of success and cure of the patient.

Ampliação de margens em cão com mastocitoma cutâneo: relato de caso / Margins enlargement in dog for cutaneous mastocytoma: case report

Objetiva-se relatar a reintervenção cirúrgica para ampliação de margens em um paciente diagnosticado com mastocitoma cutâneo. Um canino, macho, Bulldog Francês, com 7 anos foi atendido com histórico de retirada de nódulo cutâneo em região abdominal há 15 dias, com diagnóstico histopatológico compatível com mastocitoma grau I e margens cirúrgicas comprometidas. Optou-se então pela realização de um segundo procedimento cirúrgico para ampliação das margens de segurança, o qual foi precedido por planejamento de 5 cm de margens cutâneas e uma camada de fáscia e um plano muscular como margem profunda, juntamente com a linfadenectomia inguinal. Durante o procedimento, foi possível a síntese sem a necessidade do uso de técnicas reconstrutivas, a partir da divulsão do subcutâneo e da utilização do padrão Walking Suture. Não houve intercorrências transoperatórias, e a formação de hematoma foi a única complicação pósoperatória observada. O material foi enviado para análise histopatológica, confirmando mastocitoma cutâneo baixo grau/grau I com margens livres, sem evidências de metástase em linfonodo. Dessa forma, não foram instituídas terapias adjuvantes, e após 320 dias pós-operatórios, o paciente apresentava-se em ótimo estado geral, sem evidências de recidiva ou metástases à distância na radiografia torácica e ultrassonografia abdominal. Conclui-se que a reintervenção cirúrgica pode ser uma alternativa para o tratamento do mastocitoma baixo grau/grau I com margens comprometidas, sendo o diagnóstico histopatológico e o planejamento cirúrgico essenciais para redução de complicações trans e pósoperatórias, aumentando as chances de sucesso e cura do paciente.(AU)

The objective is to report the surgical reintervention for enlarging margins in a patient diagnosed with cutaneous mast cell tumor. A canine, male, French Bulldog, 7 years old, was seen with a history of skin nodule removal in the abdominal region 15 days ago, with a histopathological diagnosis compatible with grade I mastocytoma and compromised surgical margins. Then, it was decided to perform a second surgical procedure to expand the safety margins, which was preceded by planning 5 cm of cutaneous margins and a layer of fascia and a muscular plane as a deep margin, in addition to inguinal lymphadenectomy. During the procedure, synthesis was possible without the use of reconstructive techniques, from the subcutaneous divulsion and the use of the Walking Suture pattern. There were no transoperative complications, and hematoma formation was the only postoperative complication observed. The material was sent for histopathological analysis, confirming low-grade cutaneous mastocytoma with free margins and no evidence of lymph node metastasis. Thus, adjuvant therapies were not instituted, and after 320 postoperative days, the patient was in excellent general condition, with no evidence of recurrence or distant metastases on chest radiography and abdominal ultrasound. It is concluded that surgical reintervention can be an alternative for the treatment of low-grade mastocytoma with compromised margins, and that histopathological diagnosis and surgical planning are essential to reduce trans and postoperative complications, increasing the chances of success and cure of the patient.(AU)

Comparison of two different vinblastine dosages for treatment of cutaneous mast cell tumor in dogs

Background: Mast cell tumors (MCT) are among the most common malignant cutaneous neoplasm in dogs with variable biologic behavior and remain a therapeutic challenge in high-grade cases. Surgery remains the primary treatment for canine MCT; however, chemotherapy and radiation therapy are commonly used to treat aggressive cases. The combination of vinblastine (VBL) at a dose of 2 mg/m² and prednisone is the classically described protocol for MCT treatment. Studies have shown the safety of higher VBL doses for dogs with MCT, but there is a lack of information regarding dose intensity and outcome as a goal after chemotherapy. This study aimed to evaluate the impact of a higher dose of VBL on MCT treatment outcome. Materials, Methods & Results: This was an observational and comparative study conducted in two different Veterinary Teaching Hospitals. Client-owned dogs with histopathological diagnosis of grade II or III MCT were selected and underwent at least four chemotherapy sessions with VBL and prednisone. The experimental group (EG) consisted of 18 dogs that received a dose of 3 mg/m² VBL treated in one institution. The control group (CG) included 31 dogs that received a dose of 2 mg/m² VBL treated at the other institution. All dogs treated in both groups had a clinical and complete blood count (CBC) evaluation performed previous the start of chemotherapy (T0) and before each weekly treatment (T1, T2, T3, and T4). After treatment, dogs in both groups were followed-up for the recurrence rate and overall survival time after diagnosis. There was no significant difference in clinical variables between EG and CG. During treatment, dogs of EG showed a significant reduction in erythrocyte, hemoglobin, and hematocrit values between T0 and T1, T2, T3, and T4 (P < 0.001). Comparatively, the CG showed significant reduction in hemoglobin (P = 0.02) and total leucocytes (P = 0.001) values in the same period. Despite these findings, these hematological...

Canine cutaneous neoplasms in the metropolitan region of Goiânia, Goiás state, Brazil / Neoplasias cutâneas caninas na região metropolitana de Goiânia, Goiás, Brasil

ABSTRACT: The present study aimed to describe the occurrence and epidemiological features of skin neoplasms diagnosed in dogs in the metropolitan region of Goiânia, Goiás state, Brazil. Diagnoses from dog biopsies from 2011 to 2016 provided by a private veterinary pathology laboratory were analyzed. The main diagnoses were mast cell tumor, hemangiosarcoma, squamous cell carcinoma, malignant melanoma, and hemangioma. Highest frequency of neoplasms was found in female dogs, dogs aged > 8 years, and purebred dogs, particularly the American Pit Bull Terriers and the Poodles. Most common sites affected by the neoplasms were the limb and the head. Using multiple correspondence analysis, groups of neoplasms were found to be associated with different epidemiological features and the size of the neoplasms was associated with the biological behavior. The results of this study described predispositions and verified the importance of different types of skin neoplasms in dogs in the region being studied.(AU)

O objetivo deste estudo foi determinar a prevalência e as características epidemiológicas das neoplasias cutâneas em cães na região metropolitana de Goiânia, Goiás. Foram analisados os diagnósticos de um laboratório do setor privado de 2011 a 2016. Mastocitoma, hemangiossarcoma, carcinoma de células escamosas, melanoma maligno e hemangioma representaram os principais diagnósticos. A maioria dos casos ocorreram em cães de raças definidas, fêmeas e com idade >8 anos. American Pit Bull Terrier e Poodle foram as raças mais encontradas. As neoplasias acometeram principalmente regiões de membros e cabeça. Pela análise de correspondência múltipla, associou-se os grupos de neoplasias com diferentes características epidemiológicas e o tamanho da neoplasia com o comportamento biológico. A comparação dos resultados com pesquisas prévias possibilitou confirmar predisposições previamente descritas e verificar a importância dos diferentes tipos de neoplasias cutâneas em cães na região estudada.(AU)

Canine cutaneous neoplasms in the metropolitan region of Goiânia, Goiás state, Brazil / Neoplasias cutâneas caninas na região metropolitana de Goiânia, Goiás, Brasil

The present study aimed to describe the occurrence and epidemiological features of skin neoplasms diagnosed in dogs in the metropolitan region of Goiânia, Goiás state, Brazil. Diagnoses from dog biopsies from 2011 to 2016 provided by a private veterinary pathology laboratory were analyzed. The main diagnoses were mast cell tumor, hemangiosarcoma, squamous cell carcinoma, malignant melanoma, and hemangioma. Highest frequency of neoplasms was found in female dogs, dogs aged > 8 years, and purebred dogs, particularly the American Pit Bull Terriers and the Poodles. Most common sites affected by the neoplasms were the limb and the head. Using multiple correspondence analysis, groups of neoplasms were found to be associated with different epidemiological features and the size of the neoplasms was associated with the biological behavior. The results of this study described predispositions and verified the importance of different types of skin neoplasms in dogs in the region being studied.(AU)

O objetivo deste estudo foi determinar a prevalência e as características epidemiológicas das neoplasias cutâneas em cães na região metropolitana de Goiânia, Goiás. Foram analisados os diagnósticos de um laboratório do setor privado de 2011 a 2016. Mastocitoma, hemangiossarcoma, carcinoma de células escamosas, melanoma maligno e hemangioma representaram os principais diagnósticos. A maioria dos casos ocorreram em cães de raças definidas, fêmeas e com idade >8 anos. American Pit Bull Terrier e Poodle foram as raças mais encontradas. As neoplasias acometeram principalmente regiões de membros e cabeça. Pela análise de correspondência múltipla, associou-se os grupos de neoplasias com diferentes características epidemiológicas e o tamanho da neoplasia com o comportamento biológico. A comparação dos resultados com pesquisas prévias possibilitou confirmar predisposições previamente descritas e verificar a importância dos diferentes tipos de neoplasias cutâneas em cães na região estudada.(AU)

Ocorrência simultânea de hemangiossarcoma e mastocitoma de grau II em cão da raça Pitbull / Simultaneous occurrence of hemangiosarcoma and grade II mast cell tumor in a Pit Bull Terrier

Background: The incidence of cutaneous neoplasms in dogs is high and quite variable. Hemangiosarcoma (HSA) and mast celltumor (MCT) are commonly diagnosed neoplasms in isolation; however, reports of concomitant occurrence in a single patientare rare. HSA is a malignant mesenchymal neoplasm of endothelial origin; the spleen is the most commonly affected organ.MCT is a common neoplasm that may affect any region of the body, without predilection for sex, although some breeds haveshown higher incidence. This report describes a case of HSA and MCT in a Pit bull terrier.Case: A 5-year-old white male Pit bull was presented to the Small Animal Clinic of the Federal Rural University of Pernambucowith nodules in preputial region measuring 5.4 x 3.7 cm and an ulcerated nodule in the right lateral thoracic region measuring23.0 x 19.0 x 5.5 cm. The owner reported surgical excision of two previous nodules one year before the consultation, but neitherwere submitted for cytopathological or post-surgical histopathological examination. Two months after the procedure, the nodulesrecurred. Cytopathological examinations of preputial and lateral thoracic nodules were performed, with a suggestive diagnosisfor HSA and MCT, respectively. Due to the unfavorable prognosis and the weakness of the animal, euthanasia was elected.Necroscopic examination revealed an ideal body condition score (4/9), hypertrophy of right pre-scapular and axillary lymphnodes, red hepatization in the apical lobe of the right lung, with multiple, soft and pigmented nodules in the spleen, liver, pancreas and testis. Several tissue samples were collected, conditioned in 10% buffered formaldehyde solution, routinely processedfor histology, and stained with hematoxylin-eosin and toluidine blue. Microscopically, the lateral thoracic nodule consisted ofround cells in cordonal arrangement, with sparse basophilic and discretely granular cytoplasm...