DIAGNÓSTICO CITOPATOLÓGICO EM NEOPLASIAS MAMÁRIAS DE CADELAS: REVISÃO DE LITERATURA

A neoplasia da glândula mamária é o segundo tumor mais frequente em cães, embora, nas cadelas seja o mais comumente encontrado. Estima-se que a incidência de malignidade de neoplasias mamárias no Brasil seja de 68,4% a 73,4%. Nesse sentido, todo o aumento de volume do tecido mamário deve ser avaliado para possível diagnóstico de neoplasias, observando-se a coloração da pele, a presença de lesões, secreções e o tamanho das mamas. A citologia por aspiração com agulha fina (CAAF) pode indicar se a formação é ou não neoplásica, porém nem sempre é fácil a interpretação. Contudo, salienta-se sua importância na distinção entre processos inflamatórios, hiperplásicos e neoplásicos, o estabelecimento do prognóstico do tumor e a identificação de locais de metástase, com vista à rápida ação no tratamento e monitorização de possíveis recidivas locais. Na literatura veterinária, quando se avaliam as duas técnicas, os resultados demonstram que a histopatologia permite um diagnóstico mais definitivo por proporcionar uma visão de conjunto, onde a arquitetura tecidual está completa

Primary Corneal Hemangiosarcoma in a Tapir (Tapirus terrestris)

Background: Hemangiosarcoma is a malignant vascular tumor commonly described in veterinary ophthalmology as emerging at the margin of the third eyelid and bulbar conjunctiva. The primary corneal attachment of the tumor is considered rare, as the cornea is an avascular structure, but there are sparse reports of primary occurrences in the cornea of dogs, cats, and horses. No reports were found in wild animals. The Tapirus terrestris, commonly known as Tapir, is a perissodactyl mammal that inhabits South America regions, being considered the largest terrestrial mammal of Brazil and one of the most popular animals in zoos in various countries. This paper aims to report the first case of primary corneal hemangiosarcoma in a 25-year-old female Tapir (Tapirus terrestris) held in captivity. Case: A 25-year-old Tapirus terrestris female presented an irregular mass in the right cornea, mucopurulent secretion, and inconclusive previous cytological evaluation. It also had a history of a milky cornea for many years, and in the last 12 months, a tissue growth was observed, as well as the occurrence of mucopurulent secretion. The menace response in the right eye was negative. In the ophthalmologic examination, a red-colored, lobed, hemorrhagic, and ulcerated mass occupying approximately 90% of the cornea was observed, and in the peripheral cornea, there was an intense discoloration. Due to the extension of the mass and visual loss, the transpalpebral enucleation was performed under general inhalation anesthesia. The histopathological analysis evidenced a vascular tumor restricted to the central peripheral cornea, composed of blood vessels of small and large caliber, showing polygonal endothelial cells with moderate atypia, anisocytosis, and anisocariasis, in addition to dense stroma and inflammatory cells. The mass occupied the anterior corneal stroma, and there was no involvement of bulbar conjunctiva, sclera, or intraocular structures. The immunohistochemical study revealed the positivity of neoplastic cells for CD31, and the proliferative index of the lesion was evaluated by the Ki-67 as inferior to 10%. Discussion: The histopathologic and immunohistochemical examinations evidenced a hypercellular lesion, and the diagnosis of primary corneal hemangiosarcoma (HSA) was possible due to the significant cellular atypia identified in the lesion. To the authors' knowledge, this is the first case of corneal hemangiosarcoma described in Tapir terrestris. The HAS is a malignant neoplasm originating in the vascular endothelial cells. There is a significant correlation between the HSA and prolonged exposure to solar radiation. The tapir of this report lived in a high-altitude region with exposure to ultraviolet rays; therefore, it might be an important predisposing factor for the HSA emergence. The chosen treatment for vascular tumors according to the visual prognostic is the lamellar keratectomy; however, the transpalpebral enucleation was the elected treatment since the eye was not visual, the neoplasm had a great extension, the animal was in advanced age and lived in captivity, and it was difficult to handle the animal without sedation to perform adjuvant therapies. Since the mass corresponded to 90% of the cornea, total removal with free edges would not be possible as described in the literature, and, therefore, there was an increased risk of relapse. In the follow-up after 3 years of surgical excision, the animal remained free of metastasis, reinforcing the diagnosis of primary corneal hemangiosarcoma. Keywords: immunohistochemistry, vascular tumors, histopathology, veterinary ophthalmology

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 two centimeters 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 one or two 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. Keywords: tumoral, neoplasm, carcinoma, metastases, histopathology, immunohistochemistry.Introdução: Na literatura existem poucas descrições de neoplasias do epidídimo em animais domésticos, principalmente considerando os tumores primários. Nos poucos relatos encontrados na literatura, as lesões foram decorrentes da invasão de neoplasia testicular ou paratesticular, como carcinoma papilar em epidídimo de um cão e de um touro e tumores mesenquimais - fibroma/fibrossarcoma, leiomioma/leiossarcoma. Em contrapartida, os mastocitomas são a segunda neoplasia mais prevalente em cães no Brasil, acometendo principalmente a pele. O objetivo desse relato é descrever pela primeira vez um mastocitoma de baixa malignidade no epidídimo de um cão sem raça definida, sem metástase ou recidiva em um período de acompanhamento de 2 anos. Caso: Um cão sem raça definida, macho, de 10 anos de idade, foi encaminhado para avaliação pré-cirúrgica para orquiectomia eletiva. Ao exame físico foi identificado aumento de volume de aproximadamente dois centímetros com aspecto irregular à palpação no pólo cranial do testículo esquerdo. No período transcirúrgico, observou-se aumento do volume testicular (4 cm de comprimento x 2 cm de largura), com consistência firme na região do vaso deferente com alterações macroscópicas na região. O testículo foi seccionado e os fragmentos encaminhados para avaliação histopatológica em formaldeído tamponado a 10%. Havia infiltrado neoplásico altamente celular circunscrito, distribuído em leçol e separado por estroma fibrovascular, e células neoplásicas arredondadas com moderada quantidade de granulação citoplasmática basofílica, e discreta anisocitose e anisocariose. Os núcleos eram arredondados com cromatina vesicular com um ou dois nucléolos distintos. Não foram observadas figuras de mitose em dez campos de alta amplificação (400x). Poucos eosinófilos foram distribuídos por toda a população de células neoplásicas. A imunohistoquímica mostrou imunocoloração para proteína KIT com coloração perimembranosa em 95% dos mastócitos neoplásicos, fornecendo um padrão KIT 1. Não houve coloração nuclear positiva para Ki67 em nenhuma célula dos cortes histológicos examinados. Foi diagnosticado um mastocitoma grau II (baixo grau de malignidade). Após o diagnóstico, o animal foi submetido a avaliação radiográfica de ultrassonografia de tórax e abdome, e nova inspeção física em busca de nódulos, placas, lesões de pele ou massas subcutâneas. Não houve metástases em tórax e cavidade abdominal, nem alterações físicas, podendo-se inferir que o epidídimo foi o sítio primário do mastocitoma. Após dois anos de orquiectomia, não houve recidiva e nenhum tratamento quimioterápico foi realizado. Discussão: Os mastocitomas extracutâneos são incomuns em animais, mas têm sido relatados em mucosa oral e nasal, nasofaringe, laringe, traqueia, intestino, linfonodos viscerais, baço, fígado, medula espinhal, intestino, ureter, conjuntiva, pulmão e mais recentemente na glândula lacrimal da terceira pálpebra. No entanto, na avaliação dos autores, essa é a primeira descrição de mastocitoma no epidídimo em cães. O diagnóstico foi estabelecido pelo exame histopatológico, que revelou mastocitoma epididimal grau II e avaliação imunohistoquímica (KIT e Ki-67) como sendo de baixa agressividade. O diagnóstico de tumor primário foi confirmado pois o estadiamento foi estabelecido após o diagnóstico histopatológico, envolvendo radiografia de tórax, ultrassonografia abdominal, avaliação cutânea em busca de nódulos, placas, lesões cutâneas e subcutâneas, e não revelou outras anormalidades ou metástases não identificadas em a avaliação pré-operatória. Além disso, a imunocoloração com KIT e Ki-67 reafirmou o baixo grau de malignidade e o potencial de metástases, o que pode ser observado pelo acompanhamento assintomático do paciente dois anos após a excisão cirúrgica

Ovarian dysgerminoma causing multifocal metastases in young bitch

The ovarian neoplasias are unusual in canine species, mainly originated from germinative cells. Among these, dysgerminoma is a rare neoplasm in bitches, predominantly affecting senile and small and medium breeds. They are large, rounded, smooth surface, painless and firm in consistency. The clinical signs commonly demonstrated by patients with this neoplasia are abdominal distension and secondary signs of hyperestrogenism. The diagnosis should be based on the association of history, clinical signs, radiographic, ultrasonographic, cytological, histopathological and immunohistochemical exams. The treatment is the surgical castration and metastases are uncommon. Due to the rarity in bitches, specifically the young animals, this study aimed to describe a case of left ovarian dysgerminoma, of considerable size and adherence in adjacent organs, in a Brazilian Fila, whose showed considerable increase in abdominal volume and progressive weight loss. The diagnosis was confirmed by means of complementary x-ray, ultrasound, histopathological and immunohistochemical tests. Even with the recommended surgical treatment (castration), the patient demonstrated severe respiratory symptoms and increased abdominal volume after two months, and the complementary exams suggested pulmonary and multifocal metastases and the tutor chose euthanasia. As presented by the results, although rare in bitches, dysgerminoma should be included in the differential of ovarian neoplasias, including the young ones

Leptospirosis in slaughtered cows in the Triangulo Mineiro, Minas Gerais: prevalence, serological profile and renal lesions

Leptospirosis is a zoonosis that affects several species of domestic and wild animals and is an important cause of economic losses in cattle in Brazil. In this study, we determined the prevalence of bovine leptospirosis in the Triângulo Mineiro region, Minas Gerais, Brazil, identified the most frequent serovars of Leptospira interrogans, and examine the renal pathological changes associated with the disease. Samples of blood serum and kidney fragments from 100 bovine females were collected in cattle abattoir. In the serological investigation 48% of the cows were positive. The serovars for which there were more reactive animals were Wolffi (24%), Hardjo (21%) and Hebdomadis (18%). Among the positive samples, 14/48 showed antibody titers greater than 1:100, and 70.83% of the seropositive animals responded to more than one Leptospira interrogans serovar. Only one farm did not have seropositive cows and in nine farms studied, six (66.66%) presented seropositive animals to the Hebdomadis serovar. At the histopathological examination, the most frequent microscopic lesions in positive animals were hyalinization (81.25%), congestion (81.25%) and hydropic degeneration (70.83%). However, these histopathological alterations were also found in kidneys of animals negative to serology, such as hyalinization (80.77%), congestion (48.07%) and hydropic degeneration (55.77%) and these findings are unrelated to positivity. Histopathological examination of the kidneys is not indicated to replace the serological diagnosis of leptospirosis, and may be used only as a complementary examination. Despite the low frequency of seropositive animals in the Triângulo Mineiro region, the disease is present in a large number of farms. Noteworthy is the high frequency of serovar Hebdomadis and it can be considered an emerging serovar in the region. The evaluation of the frequency of this serovar in other regions becomes important, and once verified should result in the recommendation of the inclusion of this serovar in the leptospirosis control

Multilobular Tumor of Bone in a Dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called of many names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobular chondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could be correlated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomatic arc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signs depending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth of MTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumor has low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describe anatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. The patient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull, which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firm consistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas. The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolated mesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleoli that was involved by eosinophilic extracellular matrix. The proposed diagnostic was bone sarcoma. Histopathological assessment showed mesenchymal neoplastic proliferation, and multilobular characteristic, the lobules had different sizes and was well organized, and they were separated by thin conjunctive septs. In the center of lobules, there was an “island” with mineralized or chondroitin bone matrix, in some of these islands there were osteoclast. The cells had moderated pleomorphism and low mitotic activity (three mitotic cells in ten high-power field). At least, it showed big necrosis areas and invasion of near tissue. In lung was observed metastatic areas, which had same histopathologic way of primary neoplasm in skull. That way, the histopathologic exam was similar to Multilobular tumor of bone grade II.Discussion: The MTB is an uncommon neoplasm, which assaults mostly skull bone in large breeds dogs and middle age of eight years old. This case accord to literature about breed size, age and local of tumor.  The clinical signs in this dog was related to region what it was growing and near structure compression. Besides that, the patient had lung metastasis, that is the principal metastatic sites according to literature. The Histopathologic exam showed the same characters of MTB, which was considered grade II according to literature. Despite MTB is an uncommon neoplasm in clinic of dogs and cats, the epidemiological knowns as age, breed and localization, anatomopathological changes, and histopathological exam allows to have a diagnosis, showing the importance of including this neoplasm in differential diagnosis of bone tumor in dogs.

Imunomarcação de micrometástases de neoplasias mamárias espontâneas em linfonodos de cadelas por meio do receptor CD44

As neoplasias mamárias caninas são as mais frequentes nessa espécie e também são comuns em mulheres. Um dos principais fatores prognósticos dessa enfermidade é a presença ou ausência de metástase em linfonodos. A metástase é um mecanismo complexo que envolve vários fatores. Em mulheres sabe-se que a molécula de adesão CD44 está relacionada com invasão e metástase. Este trabalho teve como objetivos: avaliar a imunomarcação de CD44 nas neoplasias mamárias malignas da cadela, com e sem metástase em linfonodos regionais; associá-la como fator prognóstico; na detecção precoce de metástase; relacioná-la com a imunomarcação de MMP-9, E-caderina e VEGF e associar com a sobrevida das cadelas. Compuseram os grupos experimentais, cadelas com tumor mamário, com (Grupo M) ou sem metástase (Grupo N) detectável em linfonodos e um grupo controle composto por tecido mamário normal. Não houve predileção por localização mamária, mas utilizou-se mais as mamas inguinais e linfonodos inguinais. As neoplasias mamárias foram classificadas de acordo com a Organização Mundial de Saúde. Para isso utilizou-se a técnica de imuno-histoquímica, em amostras incluídas em parafina. Para a determinação da porcentagem de imunomarcação considerou-se somente as células epiteliais neoplásicas. Para o anticorpo CD44 contou-se as marcações em linfócitos T nos linfonodos dos dois grupos Observou-se aumento significativo na marcação do CD44 do sítio primário do tumor para a metástase, assim como nas marcações de MMP-9 e E-caderina. As marcações em linfócitos T foram maiores no grupo N e menores no grupo M. O tipo histopatológico mais comum foi o carcinoma simples túbulo papilífero. A raça predominante no grupo das metástases foi Teckel, com idade média de 9,4 anos, e com tempo de sobrevida de sete meses. Concluiu-se...Mammary neoplasia are the most frequently type of cancer in bitches and also in women. One of the main prognostic factors of this desease is the presence or absent of lymphonodes metastasis. Metastasis is a complex mechanism which involve multiple factors. At women, researchs have shown that the CD44, a adhesion molecule, is related with invasion and metastasis. This research looked for as objectives: Evaluation of CD44 in malignant mammary neoplasia at bitches with and without lymphonodes metastasis; link CD44 and prognosis; CD44 and early detection of metastasis; link CD44 with MMP-9; E-cadherin and VEGF; and associate with the survival of bitches. Experimental groups were arranged with bitches suffering from mammary neoplasia and divided into three groups: Group one(M) were compounded by bitches with visible metastasis in the lymphonodes; Group two(N) were compounded by bitches without visible metastasis in the lymphonodes;Group three or control compounded by bitches with normal mammary tissue. During the research did not have predilection about the mammary localization, despite inguinal breast and lymphonodes were more collected. Mammary neoplasias were classified according to the OMS norms. For this we used the technique of immunohistochemistry in paraffin sections and counted only epithelial cancer cells by method of percentage of labeled cells. Only antibody to CD44 told that the markings on T lymphocytes in lymph nodes of the two groups observed a significant increase in CD44 marking the site of the primary tumor to metastasis, as well as the markings of MMP-9 and E-cadherin. The markings on T lymphocytes were higher in group N and lower in group M. The most common pathological type was the simple tubular papillary carcinoma. The xiii predominant race in the group of metastasis was Daschshund, mean age 9,4 years, and survival... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Imunodetecção de células-tronco tumorais em neoplasias mamárias caninas

Neoplasias mamárias são muito frequentes em cadelas. Entre 50 e 70% são malignas. Estudos recentes sobre carcinogênese têm abordado a detecção de células-tronco tumorais (CTTs) em neoplasias mamárias. A CTT é uma célula capaz de se autorrenovar e se diferenciar em células maduras no tecido a qual está inserida. Estudos em cães demonstraram marcações de CTTs por citometria de fluxo em culturas de neoplasias mamárias. Nesse estudo objetivou-se detectar as CTTs por meio de reações imuno-histoquímicas e relacioná-las com graus e tipos histológicos de neoplasias mamárias caninas. Para isso, 136 neoplasias mamárias classificadas de acordo com Cassali et al. (2011) foram selecionadas. Utilizou-se os anticorpos CD44, CD24, Oct-4 e ALDH-1. Quarenta apresentaram o fenótipo CD44+/CD24-, sendo a maioria em graus mais avançados e nas metástases. Para o marcador Oct-4 foi observado aumento significativo de células marcadas nos carcinomas sólidos, do grau II para o grau III. A marcação para o ALDH-1 quando positiva, associou-se com as neoplasias de maior grau de malignidade (II e III). Nos carcinossarcomas não houve diferença significativa entre a marcação dos componentes epiteliais e mesenquimais para os marcadores estudados. No grupo dos adenomas foram observadas poucas células marcadas para CD44 com aumento significativo de células marcadas para os anticorpos CD24 e Oct-4. Nesse grupo não foram observadas marcações para o ALDH-1. O inverso ocorreu nas metástases, sendo a marcação significativamente maior para o anticorpo CD44 e pouco ou ausente nos demais. Em estudos realizados em cães por citometria de fluxo foram encontradas porcentagens de marcações para o fenótipo CD44/CD24 semelhantes aos encontrados nesse trabalho. As marcações para o anticorpo Oct-4 nos carcinomas sólidos condiz...Canine mammary neoplasias are very common in dogs and most of them are considered malignant. Strategies to new ways to treat these cancers have been proposed as the detection of cancer stem cells (CSC). A CSC is a cell able to self-renew and have abilities to form metastases. In canine mammary tumors these CSCs were isolated by flow cytometry by means of the surface markers CD44+/CD24-. The aims of this study was detect these CSCs by immunohistochemical reactions and relate them with grades and histological types of canine mammary neoplasias. Thus a sample of 136 breast neoplasias classified according by Cassali et al. (2011) were selected and performed immunohistochemical study for antibodies CD44, CD24, Oct-4 and ALDH-1. From 130 samples, 40 showed the phenotype CD44+/CD24-, mostly in the metastases. Grades III normally exhibited more CD44 than CD24. For the marker Oct-4 was significantly increased only in solid carcinomas. The ALDH-1 when present, is associated with a worse prognosis. In carcinosarcomas no significant difference between epithelial and mesenchymal components for markers of CSCs. Benign tumors scored low CD44, high to CD24 and Oct-4 and failed to score ALDH-1. In studies in dogs by flow cytometry were found percentages of CSCs markings similar to those found... (Complete abstract click electronic access below)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Imunomarcação da transição epitélio-mesenquima na neoplasia mamária primária de cadelas e sua metástaseem linfonodo

RESUMO: Os carcinomas mamários em cães apresentam alta capacidade metastática o que confere menor sobrevida para os pacientes com este tipo de neoplasia. O fenótipo transição epitélio-mesênquima, caracterizado pela troca dos filamentos intermediários de citoqueratina por vimentina, além da perda da proteína de adesão entre células (E-caderina) está relacionado com a maior ocorrência de metástase. Diante disto, objetivou-se avaliar, por meio de imunomarcações, a expressão de vimentina, citoqueratina e E-caderina nos tumores mamários caninos e suas metástases em linfonodo, a fim de avaliar o comportamento celular frente a esta neoplasia. Foram analisados cinco casos de neoplasias mamárias primárias caninas e suas respectivas metástases em linfonodos. Foram comparadas as médias de imunomarcações do grupo de neoplasias primárias com as médias do grupo metástase. Não houve diferença estatística nas imunomarcações da citoqueratina (p=0,1407) e E-caderina (p= 0,312) entre os grupos, apesar da média de expressão da E-caderina ter sido maior no grupo de metástases. A expressão da vimentina foi maior nos sítios das metástases (p=0,0462). Conclui-se que a expressão de vimentina aumenta no foco da metástase em relação aos seus respectivos tumores primários mamários caninos, caracterizando alteração estrutural celular, conferindo um fenótipo transição epitélio-mesênquima. Além da E-caderina apresentar fortes indícios de aumento no foco da metástase caracterizando maior adesão