Cutaneous epitheliotropic lymphoma in a Lhasa Apso

Background: Lymphoma neoplasms originate from the lymphocytes. Anatomically, these tumors can be classified into multicentric, digestive, mediastinal, and cutaneous forms. The etiology of cutaneous lymphoma remains unclear; however, it has been associated with chronic skin inflammation. The definitive diagnosis is based on histological analysis and immunohistochemistry, although fine-needle aspiration cytology has shown good results. The aim of this paper is to describe the clinicopathological aspects of a case of cutaneous epitheliotropic T cell lymphoma, classified as mycosis fungoides, in a Lhasa Apso dog. Case: A 8-year-old bitch Lhasa Apso with multiple non-pruritic skin nodules and history of 10-day evolution was referred to the Veterinary Hospital of the Centro Universitário do Espírito Santo (UNESC), Colatina, ES, Brazil. The nodules were erythematous, exophytic, firm, circumscribed, and measured 0.2-4 cm in diameter in locations throughout the animal's body. An incisional biopsy was performed with an 8-mm punch and sent for histopathological examination. An infiltrative, poorly demarcated, non-encapsulated, densely cellular neoplasm, which was replacing the dermal collagen and displacing the adnexa, was observed in the dermis. The tumor was composed of a population of round cells, with generally distinct cell borders and a small-to-moderate amount of eosinophilic cytoplasm. The nuclei were irregularly rounded and occasionally edentulous, with vesicular chromatin, a visible nucleus, and 11 mitotic figures in an area of 2.37 mm2 . The immunohistochemical test, which was positive for the CD3 marker, confirmed the diagnosis of T cell lymphoma. On an ultrasound to identify metastasis, the liver showed heterogeneous parenchyma, heterogeneous expansive formation, areas of cavitary appearance, and cytology compatible with lymphoma. Antineoplastic chemotherapy was administered using the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone). However, the animal died after 45 days. Discussion: A diagnosis of the mycosis fungoides type of cutaneous epitheliotropic T cell lymphoma was established based on clinical, laboratory, anatomopathological, and immunohistochemical findings. Pruritus is a common clinical condition in animals with mycosis fungoides, particularly in those with the erythrodermic form of the disease. Epitheliotropic lymphomas have no sexual or racial predilections and usually affect dogs over 9 years of age. The Cocker Spaniel, English Bulldog, Boxer, Golden Retriever, Scottish Terrier, Briard, English Springer Spaniel, Beagle, German Shepherd, and English Cocker Spaniel breeds are frequently affected by these lymphomas. These neoplasms can have a primary skin origin, or they can be secondary and associated with lymphoma found elsewhere in the body. Chemotherapy is the treatment of choice, especially in cases with multifocal distribution. Protocol preference varies with disease stage, patient clinical and laboratory conditions, and the degree of toxicity. Commonly used chemotherapy regimens include L-CHOP (vincristine, cyclophosphamide, doxorubicin, L-asparaginase, and prednisolone), CHOP, COP (cyclophosphamide, vincristine, and prednisone), LAP (lomustine, L-asparaginase, and prednisolone), LOPP (lomustine, vincristine, procarbazine, prednisolone), chlorambucil, and prednisolone. The prognosis of canine epitheliotropic cutaneous lymphoma is unfavorable, with a survival time ranging from a few months to 2 years. The animal in this study survived for 105 days. In addition, epitheliotropic cutaneous T cell lymphoma is aggressive, which may result in a shorter survival time in animals affected by this type of tumor.

Multilobular tumor of bone in bitches: clinical, histopathological, immunohistochemical and overall survival aspects

Background: Multilobular tumor of bone (MTB) is an unusual neoplasm with variable biologic behavior which originates primarily in bone tissues. Radiographs computed tomography (CT), and magnetic resonance imaging (MRI) are useful in diagnoses and surgical planning. Tumor removal with wide surgical margins is the treatment of choice. Immunohistochemistry has been shown as an important tool in veterinary oncology to define therapeutic and prognostic decisions. The goal of this study was to report 2 distinct cases of multilobular tumor of bone, their Cox-2 and Mib-1 immunohistochemical profile and its impact on overall survival. Case: Two bitches were presented at the Oncology Department of the Veterinary Hospital in the Veterinary School of Universidade Federal de Minas Gerais (UFMG). Both had a history of a progressive, painless, circumscribed, and firm facial mass. The 1st patient was a 8-year-old intact bitch mixed breed, weighing 50 kg, that presented a fast growing right infraorbital 3-cm mass, causing eye displacement. The 2nd patient was a 7-year-old spayed bitch Labrador retriever, weighing 28 kg, that presented a left temporal 8-cm mass. Neurologic examination of both bitches was normal. Skin over the nodules was strained, but with no ulceration. Radiographic exams of the head revealed lytic and proliferative bone reaction, with loss of cortical definition in both cases. These alterations were seen on the left zygomatic arch of the retrobulbar region, involving part of the mandible and of the nasal sinus lateral frontal bone in 1st patient, and on the right temporal process of the zygomatic bone in 2nd patient. The last one, also showed a granular solid mass with little contact with skull bones. Complete blood count, biochemistry profile, electrocardiogram, and 3-view thoracic radiographs were performed. Results were within normal ranges for the species and no signs of metastasis was seen on the radiographs. Location, size, and density of the mass, adjacent tissue compression, absence of cranial invasion, and lymph node size were rigorously evaluated with CT, allowing an individualized surgical planning to achieve complete mass removal and maintenance of the function of adjacent structures. Both animals were submitted to surgery. Both tumors were fixed on 10% neutral buffered formalin and sent to the Animal Pathology Department of UFMG for histopathological examination and margin assessment. Both tumors were diagnosed as grade I MTB. Tumor immunohistochemistry was performed to identify prognostic factors that could be used to better define therapeutic treatments and to try to clarify the discrepancy in disease progression between both tumors. The 1st patient expressed 20% of Mib-1 and was considered score 2 of Cox-2. The 2nd one expressed 5% of Mib-1 and was considered score 1 of Cox-2. Considering the diagnoses and histological characteristics of the tumors, it was decided for clinical follow-up of patients without additional therapeutic complementation. Even considering incomplete surgical margins in 2nd patient, adjuvant chemotherapy was not performed, due to low mitotic index and low histological grade. The 1st patient had an overall survival of 240 days, and death was due to recurrence and disease progression; and the 2nd did not show recurrence nor metastasis after 1200 days. Discussion: Proper and individualized surgical planning and histopathological evaluation are extremely important to guide treatment decisions. However, immunohistochemistry can be important in MTB cases, to help define which patients should be submitted to surgery alone and which patients could be benefited from adjuvant chemotherapy.

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.

Cutaneous squamous cell carcinoma with mucinous metaplasia in dogs

Background: Squamous cell carcinoma (SCC) is one of the most common malignant skin tumors in domestic animals. Histologically, they are characterized by a proliferation of neoplastic keratinocytes with varied keratin production. Some SCCs have peculiar histological characteristics that permit them to be classified into uncommon to rare histological subtypes, reported in animals and humans. However, according to the authors' knowledge, the mucin-producing subtype described in humans has not yet been reported in animals. In this study, we report the occurrence of two mucin-producing SCCs in dogs, a histological presentation similar to that seen in cutaneous SCCs with mucinous metaplasia in humans. Cases: Two dogs, a 5-year-old Yorkshire female and a 17-year-old Dachshund male, had a skin nodule near the tail and on the right eyelid. The nodules varied from 1 to 5 cm in diameter, were firm and covered with skin and hair. The cut surface was firm and white. Histological findings were compatible with squamous cell carcinoma, characterized by a neoplastic proliferation of keratinocytes originating in the epidermis and infiltrating the dermis. The keratinocytes were arranged in islands and occasional anastomosed cords, supported by a fibrous stroma. The formation of pearls varied from moderate to sparse. The nuclear and cellular pleomorphism was accentuated in case two and moderate in case one. Mitosis figures ranged from two to five in a high magnification field. Within the neoplasm, there were large vacuolated neoplastic cells with slightly fibrillar intracytoplasmic basophilic content. This content has been rarely observed in an extracellular medium. The presence of mucin was confirmed by positive Alcian Blue (AB) staining. In immunohistochemistry (IHC), tumor cells showed strong immunostaining for pancitokeratin, and in areas with marked mucin deposition, immunostaining was predominantly moderate to weak. No tumor cells were immunostained for CD34 and Bcl-2 antibodies. Compared to AB and Harris' hematoxylin, it was possible to demonstrate the presence of mucin in the cytoplasm of neoplastic keratinocytes using IHC. No vascular or lymphatic invasion by neoplastic cells was observed. The average cell proliferation index assessed by counting the nucleolar argyrophilic organizing regions (AgNOR) was 3.4 in case 1 and 4.5 in case 2. Discussion: Although the SCC routinely does not present a diagnostic challenge in veterinary practice, the histological presentation of the reported cases does not fit the current classification available in veterinary medicine. The histological presentation observed in these two dogs is similar to that described for cutaneous SCCs with mucinous metaplasia in humans, and so far not described in animals. The observation of intracytoplasmic mucin in humans is an essential finding for the diagnosis of SCC with mucin metaplasia. In the present cases, we observed a slightly basophilic amorphous substance in the cytoplasm of proliferated neoplastic keratinocytes, which stained strongly in blue when applied the Alcian Blue (AB) histochemical technique. This observation became more evident when using IHC counterstained with AB and Harris hematoxylin. In the histological analysis, the absence of an adenoid growth pattern or glandular formation amid neoplastic proliferation ruled out the possibility of a mucinous adenocarcinoma or a mucoepidermoid carcinoma. In addition, we could rule out a follicular neoplasia, including keratinizing infundibular acanthoma due to the absence of a central pore and the absence of immunostaining for CD34 and Bcl-2. These immunohistochemical findings, together with histological findings, reinforce the diagnosis of SCC with mucinous metaplasia in our dogs.(AU)

Primary ocular transmissible venereal tumor in a prepubescent female dog

Background: Canine transmissible venereal tumor (CTVT) is a peculiar neoplasm resulting from the transmission of hostcancerous cells to another canid by implantation. Transmission occurs among reproductive age dogs, especially thosewith unrestricted sexual activity. It usually occurs on the external genitalia of dogs and other areas are unusual. However,implants have been described in injured mucosa, as well as metastases in lymph nodes, spleen, skin, anus and perianalspace, oral mucosa, nasal mucosa, eyeball and brain. The purpose of this report is to describe the first case of exclusivelyextragenital ocular CTVT in a prepubescent female dog.Case: A 6-month-old mixed-breed, non-spayed and prepubescent female dog, showing a fast-growing reddish-coloredmass in the right eye (RE), was examined. Blepharospasm, mild serosanguineous secretion, chemosis and a smooth surfacereddish mass with 2.5 cm in length occupying the orbital area were observed during physical examination, impairing thevisualization of the right eyeball. For ocular ultrasonography examination of the affected eye, acepromazine was used (0.03mg/kg) associated with methadone (0.3 mg/kg) intramuscularly, and propofol (4 mg/kg) for induction and 0.2 mg/kg formaintenance, intravenously. Ultrasonography examination evidenced an amorphous hyperechogenic structure, medial tothe RE, with homogeneous echotexture, punctiform vascularization to amplitude Doppler (Power Doppler), measuring 2.8cm in length and 1.4 cm in diameter, causing eyeball distortion and rejection. Based on ultrasonography results and withthe patient still anesthetized, an incisional biopsy of the peribulbar mass was performed with a 5 mm disposable punch.The final CTVT diagnosis was possible after histopathological analysis. No more CTVT nodules were found, especiallyin the vulva, which had a prepubescent appearance, consistent with age. Treatment...

Primary ocular transmissible venereal tumor in a prepubescent female dog

Background: Canine transmissible venereal tumor (CTVT) is a peculiar neoplasm resulting from the transmission of hostcancerous cells to another canid by implantation. Transmission occurs among reproductive age dogs, especially thosewith unrestricted sexual activity. It usually occurs on the external genitalia of dogs and other areas are unusual. However,implants have been described in injured mucosa, as well as metastases in lymph nodes, spleen, skin, anus and perianalspace, oral mucosa, nasal mucosa, eyeball and brain. The purpose of this report is to describe the first case of exclusivelyextragenital ocular CTVT in a prepubescent female dog.Case: A 6-month-old mixed-breed, non-spayed and prepubescent female dog, showing a fast-growing reddish-coloredmass in the right eye (RE), was examined. Blepharospasm, mild serosanguineous secretion, chemosis and a smooth surfacereddish mass with 2.5 cm in length occupying the orbital area were observed during physical examination, impairing thevisualization of the right eyeball. For ocular ultrasonography examination of the affected eye, acepromazine was used (0.03mg/kg) associated with methadone (0.3 mg/kg) intramuscularly, and propofol (4 mg/kg) for induction and 0.2 mg/kg formaintenance, intravenously. Ultrasonography examination evidenced an amorphous hyperechogenic structure, medial tothe RE, with homogeneous echotexture, punctiform vascularization to amplitude Doppler (Power Doppler), measuring 2.8cm in length and 1.4 cm in diameter, causing eyeball distortion and rejection. Based on ultrasonography results and withthe patient still anesthetized, an incisional biopsy of the peribulbar mass was performed with a 5 mm disposable punch.The final CTVT diagnosis was possible after histopathological analysis. No more CTVT nodules were found, especiallyin the vulva, which had a prepubescent appearance, consistent with age. Treatment...(AU)

Tricoblastoma em cão: uma análise clínica, diagnóstica e terapêutica / Trichoblastoma in a dog: a clinical, diagnostic and therapeutic analysis

Background: Trichoblastoma is a rare skin neoplasm derived from the primitive hair follicle, having epithelial and mesenchymal components. Despite being commonly described as a benign tumor, there are reports in the literature of tumors with characteristics of malignant neoplasia. It affects adult dogs and cats, with no predilection for sex. Although rare, in studies in Brazil the pathology shows variable rates of occurrence. This work describes a case of tricoblastoma in a 4-year-old mixed breed dog, submitted to care at the Veterinary Hospital of the Federal University of Western Bahia (HVU-UFOB). Case: A 4-year-old male mixed breed dog with 7 kg of body weight, was referred to the HVU-UFOB. The main complaint reported by the canine’s tutor was an increase in volume in the region of the animal’s face, which evolved slowly, associated with itching, bleeding and sensitivity to touch. During the physical examination, a round, elevated mass was observed in the subcutaneous tissue of the left face, in the mandible region, with local alopecia. On palpation, the neoformation showed a firm consistency, well-defined and fluctuating, with no solutions for continuity or discomfort to touch. The animal’s physiological parameters were within the normal for the species. CBC, chest X-rays, abdominal ultrasound and aspiration cytology of the mass were requested. The blood count and image tests did not reveal any changes. On cytological examination, small, grouped basal epithelial cells were observed, characterized by a high nucleus-cytoplasm ratio, monomorphic nuclei and intensely basophilic and pigmented cytoplasm, a suggestive diagnosis of basal cell tumor. Due to the findings, an excisional biopsy of the mass was performed, with margins of 2 cm. The mass with its margins was sent for histopathological examination at the Animal Pathology Laboratory of the HVU...

Intradural extramedullary plasmacytoma in a dog

Background: Plasmacytoma is a neoplasm originating in plasma cells, derived from B lymphocytes. Extramedullary presentation is the most common form of plasmacytoma, mainly in the skin and rarely in other tissues, including the vertebral canal. Extramedullary plasmacytoma (EMP) occurs more frequently in senile dogs and rarely in cats and some dog breeds have predisposition for this type of neoplasm. The aim of this study was to report plasmacytoma in a dog located adjacent to the thoracic vertebrae. Case: An approximately 5-year-old mongrel male with sudden paraplegia resulting from upper motor neuron injury was admitted to a University Hospital. The dog presented a six-centimeter diameter mass in the dorsal region, adjacent to the thoracic vertebrae. The leucogram presented mild leukopenia by eosinopenia and lymphopenia. Myelogram associated with epidurography showed a fill failure in the contrast column between the seventh and ninth thoracic vertebrae, and there were no osteolysis points in the thoracic vertebrae, adjacent to the neoplastic mass. The evaluation of the intervertebral spaces between the fourth to ninth thoracic vertebrae presented no increase in radiopacity, nor alterations in the size of intervertebral spaces, indicating intervertebral disc extrusion. The laterolateral radiographs showed an alignment of the vertebrae and vertebral canal, without presence of bone neoformations on the ventral face of the vertebral bodies. The animal was euthanized and fragments of mass were collected for histological analysis. Macroscopic findings presented a non-encapsulated well-delimited mass, with color ranging from white to reddish. Microscopically, there was proliferation of moderately differentiated round cells in bone and muscle tissues, arranged in mantle

Intradural extramedullary plasmacytoma in a dog

Background: Plasmacytoma is a neoplasm originating in plasma cells, derived from B lymphocytes. Extramedullary presentation is the most common form of plasmacytoma, mainly in the skin and rarely in other tissues, including the vertebral canal. Extramedullary plasmacytoma (EMP) occurs more frequently in senile dogs and rarely in cats and some dog breeds have predisposition for this type of neoplasm. The aim of this study was to report plasmacytoma in a dog located adjacent to the thoracic vertebrae. Case: An approximately 5-year-old mongrel male with sudden paraplegia resulting from upper motor neuron injury was admitted to a University Hospital. The dog presented a six-centimeter diameter mass in the dorsal region, adjacent to the thoracic vertebrae. The leucogram presented mild leukopenia by eosinopenia and lymphopenia. Myelogram associated with epidurography showed a fill failure in the contrast column between the seventh and ninth thoracic vertebrae, and there were no osteolysis points in the thoracic vertebrae, adjacent to the neoplastic mass. The evaluation of the intervertebral spaces between the fourth to ninth thoracic vertebrae presented no increase in radiopacity, nor alterations in the size of intervertebral spaces, indicating intervertebral disc extrusion. The laterolateral radiographs showed an alignment of the vertebrae and vertebral canal, without presence of bone neoformations on the ventral face of the vertebral bodies. The animal was euthanized and fragments of mass were collected for histological analysis. Macroscopic findings presented a non-encapsulated well-delimited mass, with color ranging from white to reddish. Microscopically, there was proliferation of moderately differentiated round cells in bone and muscle tissues, arranged in mantle…(AU)

Histopathological study of canine sebaceous tumors and their association with PCNA expression by immunohistochemistry / Estudo histopatológico de tumores sebáceos caninos e sua associação com a expressão de PCNA por imuno-histoquímica

Sebaceous tumors are common in dogs. These tumors include both benign and malignant lesions. Immunohistochemical evaluation of these tumors can aggregate information regarding the origin and degree of malignancy of the lesions. Focusing on this matter, sixty-one samples including normal skin and sebaceous tumors were selected from dogs of various breeds and ages, with no predilection for sex, from the archive of Veterinary Pathology Service of Federal Fluminense University, Niterói/RJ, Brazil. The samples underwent to histological processing, routine staining and immunohistochemistry with anti-PCNA (proliferating cell nuclear antigen). Descriptive statistical analysis was performed, the Wilcoxon-Mann-Whitney test was used to compare the distribution of anti-PCNA labelling in different groups of variables. In case there were more than two groups, the Analysis of Variance (ANOVA) test was performed. The mean age of the affected animals was 10.56 years. The most affected breeds were Caniches and Cocker Spaniels, as well as mixed breed animals. There was immunostaining of PCNA in both benign and malignant tumors, as well as in hyperplasic lesions with varying intensity. Most of the tumors were neoplasms which represented 67.27% of the total sample; within these, 75.00% were benign. The most frequent neoplasm was sebaceous adenoma (37.74%). Results indicated no statistical difference in the distribution of anti-PCNA labelling between the groups of sex, age, reproductive status, localization, size of tumor, and histopathological diagnosis. Although there are not many studies analyzing anti-PCNA labelling in sebaceous tumors, several of them pointed out to the predictive value in other neoplasms. With this matter in mind, we intended to evaluate the expression of anti-PCNA in canine sebaceous tumor and a possible association with the malignancy of the lesions.

Tumores sebáceos são comuns em cães. Tais tumores incluem lesões benignas e malignas. A avaliação imunohistoquímica desses tumores pode agregar informações sobre a origem e o grau de malignidade das lesões. Para este fim, sessenta e uma amostras, incluindo pele normal e tumores sebáceos foram selecionadas de cães de várias raças e idades, sem predileção por sexo, do arquivo do Serviço de Patologia Veterinária da Universidade Federal Fluminense, Niterói/RJ, Brasil. As amostras passaram por processamento histológico, coloração de rotina e imuno-histoquímica com anti-PCNA (proliferating cell nuclear antigen). Foram realizadas análises estatísticas descritivas além dos testes de Wilcoxon-Mann-Whitney para comparar a distribuição da marcação de anti-PCNA entre grupos de variáveis. Para variáveis com mais de dois grupos, aplicou-se a Análise de Variância (ANOVA). A idade média dos animais afetados foi de 10.56 anos. As raças mais afetadas foram Caniches e Cocker Spaniel, e ainda animais sem raça definida. Houve imunomarcação de PCNA em tumores benignos, malignos, e ainda em lesões hiperplásicas com intensidade variada. A maioria dos tumores eram neoplásicos representando 67.92% do total; destes, 75.00% eram benignos. O adenoma sebáceo foi a neoplasia mais frequente (37.74%). Não foram encontradas diferenças significativas nas distribuições de anti-PCNA entre os grupos das variáveis sexo, idade, status reprodutivo, localização e tamanho do tumor e diagnóstico histopatológico. Embora não haja estudos com anti-PCNA em tumores sebáceos caninos, numerosas publicações apontam seu valor preditivo em outras neoplasias. Com isso, a finalidade deste estudo foi avaliar a expressão de anti-PCNA em tumores sebáceos caninos e sua possível associação com a malignidade das lesões.

Histopathological study of canine sebaceous tumors and their association with PCNA expression by immunohistochemistry / Estudo histopatológico de tumores sebáceos caninos e sua associação com a expressão de PCNA por imuno-histoquímica

Sebaceous tumors are common in dogs and include benign and malignant lesions. The increase in immunohistochemical evaluation of sebaceous tumors aggregates information regarding the origin and degree of malignancy of the lesions. The objective of this study was to evaluate PCNA immunohistochemical expression of  sebaceous tumors in dogs. Sixty-one samples include normal skin and sebaceous tumors were selected from dogs of various breeds and ages, no gender predilection, sent to the Veterinary Pathology Service of Universidade Federal Fluminense, Niterói/RJ, Brazil. Samples passed through histological processing, routine staining and immunostaining from PCNA. Descriptive statistical analysis, Wilcoxon-Mann-Whitney and Fishers exact test were performed. The mean age of the affected animals was 10.56 years. There was no sexual predilection. Breeds more frequently affected were: Poodles, mixed-breed dogs and Cocker Spaniels. Most of the tumors were neoplasms (67.27%), and 75.67% of those were benign. Sebaceous adenoma was the most frequent neoplasm (56.75%). PCNA immunoexpression was present in hyperplasia, benign and malignant tumors. No previous studies were found using PCNA antibody in sebaceous tumors of dogs. Thus, more studies are needed to provide greater clarity regarding the role of these markers on normal skin and sebaceous tumors of dogs, as well as their use as prognos(AU)

Tumores sebáceos são comuns em cães. Tais tumores incluem lesões benignas e malignas. A avaliação imunohistoquímica desses tumores pode agregar informações sobre a origem e o grau de malignidade das lesões. Para este fim, sessenta e uma amostras, incluindo pele normal e tumores sebáceos foram selecionadas de cães de várias raças e idades, sem predileção por sexo, do arquivo do Serviço de Patologia Veterinária da Universidade Federal Fluminense, Niterói/RJ, Brasil. As amostras passaram por processamento histológico, coloração de rotina e imuno-histoquímica com anti-PCNA (proliferating cell nuclear antigen). Foram realizadas análises estatísticas descritivas além dos testes de Wilcoxon-Mann-Whitney para comparar a distribuição da marcação de anti-PCNA entre grupos de variáveis. Para variáveis com mais de dois grupos, aplicou-se a Análise de Variância (ANOVA). A idade média dos animais afetados foi de 10.56 anos. As raças mais afetadas foram Caniches e Cocker Spaniel, e ainda animais sem raça definida. Houve imunomarcação de PCNA em tumores benignos, malignos, e ainda em lesões hiperplásicas com intensidade variada. A maioria dos tumores eram neoplásicos representando 67.92% do total; destes, 75.00% eram benignos. O adenoma sebáceo foi a neoplasia mais frequente (37.74%). Não foram encontradas diferenças significativas nas distribuições de anti-PCNA entre os grupos das variáveis sexo, idade, status reprodutivo, localização e tamanho do tumor e diagnóstico histopatológico. Embora não haja estudos com anti-PCNA em tumores sebáceos caninos, numerosas publicações apontam seu valor preditivo em outras neoplasias. Com isso, a finalidade deste estudo foi avaliar a expressão de anti-PCNA em tumores sebáceos caninos e sua possível associação com a malignidade das lesões.(AU)

Histopathological study of canine sebaceous tumors and their association with PCNA expression by immunohistochemistry / Estudo histopatológico de tumores sebáceos caninos e sua associação com a expressão de PCNA por imuno-histoquímica

Sebaceous tumors are common in dogs and include benign and malignant lesions. The increase in immunohistochemical evaluation of sebaceous tumors aggregates information regarding the origin and degree of malignancy of the lesions. The objective of this study was to evaluate PCNA immunohistochemical expression of  sebaceous tumors in dogs. Sixty-one samples include normal skin and sebaceous tumors were selected from dogs of various breeds and ages, no gender predilection, sent to the Veterinary Pathology Service of Universidade Federal Fluminense, Niterói/RJ, Brazil. Samples passed through histological processing, routine staining and immunostaining from PCNA. Descriptive statistical analysis, Wilcoxon-Mann-Whitney and Fishers exact test were performed. The mean age of the affected animals was 10.56 years. There was no sexual predilection. Breeds more frequently affected were: Poodles, mixed-breed dogs and Cocker Spaniels. Most of the tumors were neoplasms (67.27%), and 75.67% of those were benign. Sebaceous adenoma was the most frequent neoplasm (56.75%). PCNA immunoexpression was present in hyperplasia, benign and malignant tumors. No previous studies were found using PCNA antibody in sebaceous tumors of dogs. Thus, more studies are needed to provide greater clarity regarding the role of these markers on normal skin and sebaceous tumors of dogs, as well as their use as prognos

Tumores sebáceos são comuns em cães. Tais tumores incluem lesões benignas e malignas. A avaliação imunohistoquímica desses tumores pode agregar informações sobre a origem e o grau de malignidade das lesões. Para este fim, sessenta e uma amostras, incluindo pele normal e tumores sebáceos foram selecionadas de cães de várias raças e idades, sem predileção por sexo, do arquivo do Serviço de Patologia Veterinária da Universidade Federal Fluminense, Niterói/RJ, Brasil. As amostras passaram por processamento histológico, coloração de rotina e imuno-histoquímica com anti-PCNA (proliferating cell nuclear antigen). Foram realizadas análises estatísticas descritivas além dos testes de Wilcoxon-Mann-Whitney para comparar a distribuição da marcação de anti-PCNA entre grupos de variáveis. Para variáveis com mais de dois grupos, aplicou-se a Análise de Variância (ANOVA). A idade média dos animais afetados foi de 10.56 anos. As raças mais afetadas foram Caniches e Cocker Spaniel, e ainda animais sem raça definida. Houve imunomarcação de PCNA em tumores benignos, malignos, e ainda em lesões hiperplásicas com intensidade variada. A maioria dos tumores eram neoplásicos representando 67.92% do total; destes, 75.00% eram benignos. O adenoma sebáceo foi a neoplasia mais frequente (37.74%). Não foram encontradas diferenças significativas nas distribuições de anti-PCNA entre os grupos das variáveis sexo, idade, status reprodutivo, localização e tamanho do tumor e diagnóstico histopatológico. Embora não haja estudos com anti-PCNA em tumores sebáceos caninos, numerosas publicações apontam seu valor preditivo em outras neoplasias. Com isso, a finalidade deste estudo foi avaliar a expressão de anti-PCNA em tumores sebáceos caninos e sua possível associação com a malignidade das lesões.

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)

Caracterização anatomopatológica e imuno-histoquímica dos tumores das glândulas cutâneas em cães / Anatomopathological and immunohistochemical characterization of skin gland tumors in dogs

O presente estudo objetivou caracterizar os aspectos anatomopatológicos e imuno-histoquímicos dos tumores das glândulas cutâneas em cães. A caracterização morfológica seguiu a classificação atualizada da Organização Mundial de Saúde. Para a caracterização imuno-histoquímica, utilizaram-se anticorpos monoclonais primários anti-citoqueratina 14 (CK14), vimentina, p63, calponina, EGFR e Ki-67. Dos animais examinados, 66,67% (18/27) eram machos e 33,33% (9/27) fêmeas, 21 tinham raça definida e seis eram sem raça definida (SRD), com idade variando entre sete e 15 anos. Dos tumores caracterizados, 40,74% eram hepatoides (11/27), 29,63% sebáceos (8/27), 25,92% apócrinos (7/27) e 3,70% meibômio (1/27). Os tumores malignos representaram 55,56%, e os benignos 44,44%. Com esses resultados, foi possível demonstrar que os tumores das glândulas cutâneas em cães são frequentes, sem predileção por raça, sexo e com idade superior ou igual a sete anos. Os anticorpos CK 14, p63, vimentina e EGFR foram imunoexpressos nas células basais, células de diferenciação sebácea dos tumores hepatoides e de meibômio e células mioepiteliais. Entretanto, a vimentina e o EGFR não demonstraram imunomarcação para os tumores sebáceos. A calponina foi um bom marcador para as células mioepiteliais. O índice de Ki-67 foi mais acentuado nos tumores malignos em relação aos benignos. No entanto, estudos futuros utilizando maior número de casos se fazem necessários.(AU)

The present study aimed to characterize the anatomopathological and immunohistochemical aspects of cutaneous glandular tumors in dogs. Tumours were diagnosed according to the WHO criteria for canine skin neoplasms. For the immunohistochemical characterization, the primary monoclonal antibodies anti-cytokeratin 14 (CK14), vimentin, p63, calponin, EGFR and Ki-67 were used. Males were 66.67% (18/27) and females 33.33% (9/27), 21 had a defined race and 6 were mixed breed, with ages varying from 7 to 15 years. The tumors characterized were 40.74% hepatoid (11/27), 29.63% sebaceous (8/27), 25.92% apocrine (7/27) and 3.70% Meibômio (1/27). Malignant tumors accounted for 55.56% and benign tumors 44.44%. With these results it was possible to demonstrate that tumors of cutaneous glands in dogs are frequent, with no predilection for race, sex and with an age ≥ seven years. The CK 14 antibodies, p63, vimentin, and EGFR were imunoexpressed in the basal cells of the sebaceous cell differentiation and Meibomian hepatoides tumors and myoepithelial to cells. However, vimentin and EGFR did not demonstrate immunostaining for sebaceous tumors. Calponin was a good marker for myoepithelial cells. The Ki-67 index was more pronounced in malignant tumors compared to benign tumors. However, more studies are needed mainly using a higher number of tumors.(AU)

Caracterização anatomopatológica e imuno-histoquímica dos tumores das glândulas cutâneas em cães / Anatomopathological and immunohistochemical characterization of skin gland tumors in dogs

O presente estudo objetivou caracterizar os aspectos anatomopatológicos e imuno-histoquímicos dos tumores das glândulas cutâneas em cães. A caracterização morfológica seguiu a classificação atualizada da Organização Mundial de Saúde. Para a caracterização imuno-histoquímica, utilizaram-se anticorpos monoclonais primários anti-citoqueratina 14 (CK14), vimentina, p63, calponina, EGFR e Ki-67. Dos animais examinados, 66,67% (18/27) eram machos e 33,33% (9/27) fêmeas, 21 tinham raça definida e seis eram sem raça definida (SRD), com idade variando entre sete e 15 anos. Dos tumores caracterizados, 40,74% eram hepatoides (11/27), 29,63% sebáceos (8/27), 25,92% apócrinos (7/27) e 3,70% meibômio (1/27). Os tumores malignos representaram 55,56%, e os benignos 44,44%. Com esses resultados, foi possível demonstrar que os tumores das glândulas cutâneas em cães são frequentes, sem predileção por raça, sexo e com idade superior ou igual a sete anos. Os anticorpos CK 14, p63, vimentina e EGFR foram imunoexpressos nas células basais, células de diferenciação sebácea dos tumores hepatoides e de meibômio e células mioepiteliais. Entretanto, a vimentina e o EGFR não demonstraram imunomarcação para os tumores sebáceos. A calponina foi um bom marcador para as células mioepiteliais. O índice de Ki-67 foi mais acentuado nos tumores malignos em relação aos benignos. No entanto, estudos futuros utilizando maior número de casos se fazem necessários.(AU)

The present study aimed to characterize the anatomopathological and immunohistochemical aspects of cutaneous glandular tumors in dogs. Tumours were diagnosed according to the WHO criteria for canine skin neoplasms. For the immunohistochemical characterization, the primary monoclonal antibodies anti-cytokeratin 14 (CK14), vimentin, p63, calponin, EGFR and Ki-67 were used. Males were 66.67% (18/27) and females 33.33% (9/27), 21 had a defined race and 6 were mixed breed, with ages varying from 7 to 15 years. The tumors characterized were 40.74% hepatoid (11/27), 29.63% sebaceous (8/27), 25.92% apocrine (7/27) and 3.70% Meibômio (1/27). Malignant tumors accounted for 55.56% and benign tumors 44.44%. With these results it was possible to demonstrate that tumors of cutaneous glands in dogs are frequent, with no predilection for race, sex and with an age ≥ seven years. The CK 14 antibodies, p63, vimentin, and EGFR were imunoexpressed in the basal cells of the sebaceous cell differentiation and Meibomian hepatoides tumors and myoepithelial to cells. However, vimentin and EGFR did not demonstrate immunostaining for sebaceous tumors. Calponin was a good marker for myoepithelial cells. The Ki-67 index was more pronounced in malignant tumors compared to benign tumors. However, more studies are needed mainly using a higher number of tumors.(AU)

A review of neoplastic and non-neoplastic canine skin tumours in Trinidad from 2010-2015

This retrospective study was performed on samples submitted to the Pathology Unit of the School of Veterinary Medicine, Faculty of Medical Sciences, St. Augustine, Trinidad, during the period 2010 to 2015. A total of 471 non-inflammatory cutaneous masses were analyzed, of which 225 (47.8%) were malignant, 202 (42.9%) were benign and 44 (9.3%) were non-neoplastic. The most common malignant tumors were haemangiosarcoma, 50 (22.2%); mast cell tumour, 49 (21.8%); soft tissue sarcoma 35 (15.6%), lymphoma, 20 (8.9%) and melanoma 20 (8.9%). The most common benign tumors were haemangioma, 39 (19.3%); lipoma, 27 (13.4%), trichoblastoma, 26 (12.9%), histiocytoma 25 (12.4%), plasma cell tumor, 23 (11.4%) and papilloma 9 (4.5%). Common non-neoplastic skin lesions included collagen naevi, 26 (59.1%) and follicular cysts, 11 (25.0%). Mixed breed dogs 241 (51.2%), was most frequently represented with neoplasms followed by Rottweilers 50 (10.6%) and Pit bulls 48 (10.1%).

A review of neoplastic and non-neoplastic canine skin tumours in Trinidad from 2010-2015

This retrospective study was performed on samples submitted to the Pathology Unit of the School of Veterinary Medicine, Faculty of Medical Sciences, St. Augustine, Trinidad, during the period 2010 to 2015. A total of 471 non-inflammatory cutaneous masses were analyzed, of which 225 (47.8%) were malignant, 202 (42.9%) were benign and 44 (9.3%) were non-neoplastic. The most common malignant tumors were haemangiosarcoma, 50 (22.2%); mast cell tumour, 49 (21.8%); soft tissue sarcoma 35 (15.6%), lymphoma, 20 (8.9%) and melanoma 20 (8.9%). The most common benign tumors were haemangioma, 39 (19.3%); lipoma, 27 (13.4%), trichoblastoma, 26 (12.9%), histiocytoma 25 (12.4%), plasma cell tumor, 23 (11.4%) and papilloma 9 (4.5%). Common non-neoplastic skin lesions included collagen naevi, 26 (59.1%) and follicular cysts, 11 (25.0%). Mixed breed dogs 241 (51.2%), was most frequently represented with neoplasms followed by Rottweilers 50 (10.6%) and Pit bulls 48 (10.1%).(AU)

Incidence of skin tumors in dogs in Salvador, Bahia state, Brazil (2007-2016) / Frequência de dermatopatias tumorais em cães da cidade de Salvador, Bahia (2007-2016)

This study aimed to establish the incidence of skin tumors (cutaneous proliferative lesions of neoplastic or non-neoplastic nature) in dogs diagnosed by histopathological evaluation at the Veterinary Pathology Laboratory (LPV) of the Federal University of Bahia (UFBA) in a 10-year (2007-2016) historical series. Of the 1945 histopathological diagnoses made in this period, 503 were skin biopsies, and 617 dermatological problems (87 dogs, 17.3%, presented more than one positive diagnosis) were found. Of the 617 diagnoses of dermatopathy, 546 (88.49%) were tumors and 71 (11.51%) were non-tumorous alterations. The 546 conditions more profoundly studied were from 453 dogs, 468 (85.7%) neoplastic and 78 (14.3%) non-neoplastic tumors. The 468 neoplasms were classified as follows: 230 benign (49.14%), 215 malignant (45.94%), 23 borderline (epitheliomas) (4.91%), 51.92% (243/468) mesenchymal, 42.74% (200/468) epithelial, 4.91% (23/468) melanocytic, and 0.43% (2/468) metastatic (mammary gland). The most commonly diagnosed neoplastic dermatopathies were mastocytoma (14.7%) and lipoma (7.48%). Among the 78 non-neoplastic conditions (14.3%), epidermal inclusion cyst (39.74%) and trichogranuloma (15.38%) were the most frequent. Canine dermatopathies accounted for 26% of the biopsy files of the LPV-UFBA. Distinct simultaneous dermatological problems were frequently found in the dogs assessed (one in six). Considering that these conditions can present with different cellular origin and biological behavior, it is crucial that histopathological evaluation be performed in fragments from the different cutaneous lesions.(AU)

Objetivou-se com esse estudo determinar a frequência de dermatopatias tumorais (lesões proliferativas cutâneas que cursam com aumento de volume de natureza neoplásicas ou não neoplásicas) em cães, diagnosticadas por exame histopatológico no Laboratório de Patologia Veterinária (LPV) da Universidade Federal da Bahia (UFBA) na série histórica de 10 anos (2007-2016). Dos 1.945 exames histopatológicos realizados no período, 503 tratava-se de biópsias cutâneas, dentre os quais, foram diagnosticados 617 dermatopatias (87 cães, 17,3%, apresentavam mais de um diagnóstico). Dos 617 diagnósticos de dermatopatias 546 (88,49%) foram tumorais e 71 (11,51%) não tumorais. As 546 dermatopatias tumorais, estudadas com mais ênfase, foram diagnosticadas em 453 cães, 468 (85,7%) eram neoplásicas e 78 (14,3%) não neoplásicas. Das 468 dermatopatias tumorais neoplásicas encontradas 230 foram benignas (49,14%), 215 malignas (45,94%), 23 borderline/epiteliomas (4,91%), 51,92% (243/468) de origem mesenquimal, 42,74% (200/468) epiteliais, 4,91% (23/468) melanocíticas e 0,43% (2/468) metastáticas para a pele (primárias de glândula mamária). As dermatopatias neoplásicas mais diagnosticadas foram o mastocitoma (14,7%) e o lipoma (7,48%). Dentre as 78 dermatopatias tumorais não neoplásicas (14,3%), os cistos de inclusão epidermal (39,74%) e o tricogranuloma (15,38%) foram os mais frequentes. As dermatopatias caninas representaram 26% da casuística no LPV/UFBA. A ocorrência de dermatopatias tumorais simultâneas distintas foi comum nos cães desse estudo (um a cada seis); como podem ter origens celulares e comportamentos biológicos diferentes, enfatiza-se a importância da coleta e envio para exame histopatológico de fragmentos das diferentes lesões cutâneas.(AU)

Incidence of skin tumors in dogs in Salvador, Bahia state, Brazil (2007-2016) / Frequência de dermatopatias tumorais em cães da cidade de Salvador, Bahia (2007-2016)

This study aimed to establish the incidence of skin tumors (cutaneous proliferative lesions of neoplastic or non-neoplastic nature) in dogs diagnosed by histopathological evaluation at the Veterinary Pathology Laboratory (LPV) of the Federal University of Bahia (UFBA) in a 10-year (2007-2016) historical series. Of the 1945 histopathological diagnoses made in this period, 503 were skin biopsies, and 617 dermatological problems (87 dogs, 17.3%, presented more than one positive diagnosis) were found. Of the 617 diagnoses of dermatopathy, 546 (88.49%) were tumors and 71 (11.51%) were non-tumorous alterations. The 546 conditions more profoundly studied were from 453 dogs, 468 (85.7%) neoplastic and 78 (14.3%) non-neoplastic tumors. The 468 neoplasms were classified as follows: 230 benign (49.14%), 215 malignant (45.94%), 23 borderline (epitheliomas) (4.91%), 51.92% (243/468) mesenchymal, 42.74% (200/468) epithelial, 4.91% (23/468) melanocytic, and 0.43% (2/468) metastatic (mammary gland). The most commonly diagnosed neoplastic dermatopathies were mastocytoma (14.7%) and lipoma (7.48%). Among the 78 non-neoplastic conditions (14.3%), epidermal inclusion cyst (39.74%) and trichogranuloma (15.38%) were the most frequent. Canine dermatopathies accounted for 26% of the biopsy files of the LPV-UFBA. Distinct simultaneous dermatological problems were frequently found in the dogs assessed (one in six). Considering that these conditions can present with different cellular origin and biological behavior, it is crucial that histopathological evaluation be performed in fragments from the different cutaneous lesions.(AU)

Objetivou-se com esse estudo determinar a frequência de dermatopatias tumorais (lesões proliferativas cutâneas que cursam com aumento de volume de natureza neoplásicas ou não neoplásicas) em cães, diagnosticadas por exame histopatológico no Laboratório de Patologia Veterinária (LPV) da Universidade Federal da Bahia (UFBA) na série histórica de 10 anos (2007-2016). Dos 1.945 exames histopatológicos realizados no período, 503 tratava-se de biópsias cutâneas, dentre os quais, foram diagnosticados 617 dermatopatias (87 cães, 17,3%, apresentavam mais de um diagnóstico). Dos 617 diagnósticos de dermatopatias 546 (88,49%) foram tumorais e 71 (11,51%) não tumorais. As 546 dermatopatias tumorais, estudadas com mais ênfase, foram diagnosticadas em 453 cães, 468 (85,7%) eram neoplásicas e 78 (14,3%) não neoplásicas. Das 468 dermatopatias tumorais neoplásicas encontradas 230 foram benignas (49,14%), 215 malignas (45,94%), 23 borderline/epiteliomas (4,91%), 51,92% (243/468) de origem mesenquimal, 42,74% (200/468) epiteliais, 4,91% (23/468) melanocíticas e 0,43% (2/468) metastáticas para a pele (primárias de glândula mamária). As dermatopatias neoplásicas mais diagnosticadas foram o mastocitoma (14,7%) e o lipoma (7,48%). Dentre as 78 dermatopatias tumorais não neoplásicas (14,3%), os cistos de inclusão epidermal (39,74%) e o tricogranuloma (15,38%) foram os mais frequentes. As dermatopatias caninas representaram 26% da casuística no LPV/UFBA. A ocorrência de dermatopatias tumorais simultâneas distintas foi comum nos cães desse estudo (um a cada seis); como podem ter origens celulares e comportamentos biológicos diferentes, enfatiza-se a importância da coleta e envio para exame histopatológico de fragmentos das diferentes lesões cutâneas.(AU)