Incidence of skin tumors in dogs in Salvador, Bahia state, Brazil (2007-2016)

English. ABSTRACT: 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.

Portuguese. RESUMO: 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.