Tumores melanocíticos em equinos: estudo clínico, histopatológico e imunohistoquímico
Ficheiros
Data
2014-03-06
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
A pele é o local mais comum de neoplasias em equinos. Supõe-se que a prevalência destas condições esteja a aumentar e estima-se que cerca de 2/3 (66%) dos tumores melanocíticos em equinos possam progredir para malignidade. A classificação destas lesões em equinos é complexa e dificulta o trabalho do patologista. A evolução ao nível das técnicas de imunohistoquímica tem sido importante no diagnóstico, prognóstico e terapêutica desta doença.
Foi realizada a excisão cirúrgica de nódulos cutâneos de 43 equinos acompanhada de inquérito. A avaliação clínica baseou-se na idade (valor mínimo de 2,5 anos e máximo de 26 anos com média de 14,9 anos), género (51,2% ocorreram em machos e 48,8% em fêmeas), raça (sobretudo Puro-Sangue Lusitano - 60,5% e Cruzado Lusitano - 27,9%), pelagem (ruça em 90,7%, isabel em 4,7%, baia em 2,3% e castanha em 2,3%), quantidade (melanoma dérmico em 11,6% e melanomatose dérmica em 88,4%), tamanho (90,7 % pequeno, 44,2% médio e 25,6% grande), localização (zona perineal em 93%, outras localizações em 27,9% e padrão difuso em 4,7%) e duração das lesões (entre 6 meses e 20 anos). As amostras foram processadas e submetidas a análise histopatológica e imunohistoquímica. As variáveis histopatológicas avaliadas foram: localização (65,1 % na derme e 34,9% na derme e epiderme), tipo celular (7,0% fusiforme, 53,5% redondo e misto em 39,5%), ulceração (presente em 23,3%), quantidade de pigmento (escassa em 11,6%, moderada em 37,2% e abundante em 51,2%), quantidade de estroma (escassa em 44,2%, moderado em 37,2% e abundante em 18,6%), êmbolos vasculares/linfáticos (presentes em 9,3% das amostras). Obteve-se uma marcação positiva para o c-Kit em 62,8% das amostras.
A quantidade, tamanho e localização das lesões são factores importantes na decisão terapêutica e no prognóstico das lesões. As variáveis histopatológicas podem ajudar a prever o comportamento dos tumores pelo que se deverá prosseguir com os estudos no sentido de estabelecer critérios direccionados para a espécie.
A expressão desta proteína c-Kit não se encontrava avaliada em tumores melanocícitos de equinos. Obteve-se imunorreactividade em todos os tumores com características de malignidade evidente, dados que poderão ter implicações no diagnóstico e terapêutica dos mesmos.
The skin is the most common site of neoplasia in the horse. It is assumed that the prevalence of this condition is increasing and it is estimated that about 2/3 (66%) of melanocytic tumors in horses can progress to malignancy. The classification of this disease in horses is complex and hinders the work of the pathologist. The development of immunohistochemistry techniques has been important in diagnosis, prognosis and therapy of this disease. Was performed the surgical excision of cutaneous nodules of 43 horses accompanied by inquiry. The clinical evaluation based on age (minimum 2.5 years old and a maximum of 26 years old with an average of 14.9 years old), gender (51.2% in males and 48.8% in females), breed (especially Lusitano - 60.5% and Lusitano Crossed Breed - 27.9%), coat color (gray in 90.7%, pearl in 4.7%, buckskin in 2.3% and bay in 2.3%), amount (dermal melanomas in 11.6% and dermal melanomatosis in 88.4%), size (90.7% small, 44.2% medium and 25.6% large), location (perineal area in 93%, other locations in 27.9% and diffuse in 4.7%) and duration of lesions (between 6 months and 20 years). The samples were processed and subjected to histopathological and immunohistochemical analysis. The histopathological variables evaluated were: location (65.1% in dermis and 34.9% in dermis and epidermis), cell type (7.0% spindle, 53.5% round and 39.5% mixed), ulceration (present in 23.3%), amount of pigment (poor in 11.6%, moderated in 37.2% and abundant in 51.2%), amount of stroma (poor in 44.2%, moderated in 37.2% and abundant in 18.6%) and vascular/lymphatic invasion (present in 9.3% of the samples). We obtained immunoreactivity for the c-Kit in 62.8% of the samples. The amount, size and location of the lesions are important factors in therapeutic decision and prognosis of the lesions. The histopathological variables can help predict the behavior of tumors, so we should continue with studies to establish criteria directed to the species. The expression of this protein c-Kit was evaluated for the first time, as far as we know, in equine melanocytic tumors. The fact that immunoreactivity was present in all tumors with features of evident malignancy may have implications on diagnosis and therapy of these tumors.
The skin is the most common site of neoplasia in the horse. It is assumed that the prevalence of this condition is increasing and it is estimated that about 2/3 (66%) of melanocytic tumors in horses can progress to malignancy. The classification of this disease in horses is complex and hinders the work of the pathologist. The development of immunohistochemistry techniques has been important in diagnosis, prognosis and therapy of this disease. Was performed the surgical excision of cutaneous nodules of 43 horses accompanied by inquiry. The clinical evaluation based on age (minimum 2.5 years old and a maximum of 26 years old with an average of 14.9 years old), gender (51.2% in males and 48.8% in females), breed (especially Lusitano - 60.5% and Lusitano Crossed Breed - 27.9%), coat color (gray in 90.7%, pearl in 4.7%, buckskin in 2.3% and bay in 2.3%), amount (dermal melanomas in 11.6% and dermal melanomatosis in 88.4%), size (90.7% small, 44.2% medium and 25.6% large), location (perineal area in 93%, other locations in 27.9% and diffuse in 4.7%) and duration of lesions (between 6 months and 20 years). The samples were processed and subjected to histopathological and immunohistochemical analysis. The histopathological variables evaluated were: location (65.1% in dermis and 34.9% in dermis and epidermis), cell type (7.0% spindle, 53.5% round and 39.5% mixed), ulceration (present in 23.3%), amount of pigment (poor in 11.6%, moderated in 37.2% and abundant in 51.2%), amount of stroma (poor in 44.2%, moderated in 37.2% and abundant in 18.6%) and vascular/lymphatic invasion (present in 9.3% of the samples). We obtained immunoreactivity for the c-Kit in 62.8% of the samples. The amount, size and location of the lesions are important factors in therapeutic decision and prognosis of the lesions. The histopathological variables can help predict the behavior of tumors, so we should continue with studies to establish criteria directed to the species. The expression of this protein c-Kit was evaluated for the first time, as far as we know, in equine melanocytic tumors. The fact that immunoreactivity was present in all tumors with features of evident malignancy may have implications on diagnosis and therapy of these tumors.
Descrição
Dissertação de Mestrado Integrado em Medicina Veterinária, Ciências Veterinárias
Palavras-chave
Equidae , Melanoma , Neoplasias cutâneas , Imunohistoquímica