Estudo da proliferação celular em tumores melanocíticos caninos
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2015-06-17
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Em cães, os tumores melanocíticos apresentam uma biologia extremamente
diversificada e o comportamento altamente agressivos. Com o objectivo de estudar o
índice proliferativo nos tumores melanocíticos caninos e comparar esses índices com a
localização e os critérios histopatológicos classicamente associados à agressividade,
foram analisados 48 tumores melanocíticos sendo 9 melanocitomas e 39 melanomas. De
cada animal foram registados os dados referentes ao animal (idade, sexo e raça) e os
dados referentes ao tumor (localização e tamanho) tendo sido feita, posteriormente, uma
avaliação das lesões na coloração de rotina com hematoxilina-eosina (HE),
relativamente aos parâmetros histopatológicos definidos, nomeadamente o tipo de
células, actividade juncional, atipia nuclear, Infiltrado linfoplasmocitário necrose,
células gigantes, proliferação intraepitelial, ulceração, estroma e as células tumorais
intravasculares.
O índice de proliferação marcada pelo Ki-67 foi avaliado por meio da
imunohistoquímica enquanto o índice mitótico foi avaliada pela coloração de HE com
branqueamento da melanina.
Com esse estudo pudemos verificar que o índice proliferativo, determinado pela
contagem de mitoses e pela marcação imunohistoquímica pelo Ki-67 variou
significativamente entre tumores melanocíticos localizados na cavidade oral e cutânea,
sendo que nos melanocitomas o índice proliferativo foi menor quando comparado com
os melanomas. Também o índice proliferativo mostrou uma correlação significativa
com a atipia nuclear e a Infiltrado linfoplasmocitário. O Ki-67 e o índice mitótico
mostraram ser estatisticamente significativos tanto nos melanomas assim como nos
tumores melanocíticos no geral, com o nível de significância de P=0,026 e P=0,001
respectivamente. Sendo assim, o estudo dos índices proliferativos pode ser bastante útil para o diagnóstico dos melanomas caninos, auxiliando o médico na escolha do melhor tratamento.
The melanocytic tumors in dogs present a biology extremely diversified and a highly aggressive behavior. With the aim of studying the proliferative melanocytic index tumors in canines and comparing these rates with the location and histopathological criteria classically associated with aggressiveness 48 melanocytic tumors were analyzed; 9 melanocytomas and 39 melanomas. Each one of the animals was recorded with the appropriate data regarding it (age, gender, and race) and the data regarding the tumor (location and size). These records having been previously made, an evaluation of the lesions in routine staining with hematoxylin-eosin, in relation to histopathological parameters defined, and in particular the type of cells, junctional activity, nuclear atypia, necrosis, inflammation, cell proliferation, large intraepithelial, ulceration, stroma and the intravascular tumor cells followed. The proliferation index marked by Ki-67 was evaluated by means of immunohistochemistry while the mitotic index was assessed by staining with HE bleaching of melanin. With this study we can check that the proliferative index determined by counting mitoses and the immunohistochemical staining for the Ki-67 varied significantly between melanocytic tumors located in the oral cavity and skin, being that in the melanocytomas the proliferative index was much lower when compared with the melanomas. Also, the proliferative index showed a significant correlation with the nuclear atypia and the inflammation. The Ki-67 and the mitotic index showed to be statistically significant in both melanomas as well as in the melanocytic tumors in general, with the significant level of P=0.026 and P=0.001 respectively. Thus, the study of proliferative indices can be very useful for the diagnosis of canine melanomas and assisting the physician in choosing the best treatment.
The melanocytic tumors in dogs present a biology extremely diversified and a highly aggressive behavior. With the aim of studying the proliferative melanocytic index tumors in canines and comparing these rates with the location and histopathological criteria classically associated with aggressiveness 48 melanocytic tumors were analyzed; 9 melanocytomas and 39 melanomas. Each one of the animals was recorded with the appropriate data regarding it (age, gender, and race) and the data regarding the tumor (location and size). These records having been previously made, an evaluation of the lesions in routine staining with hematoxylin-eosin, in relation to histopathological parameters defined, and in particular the type of cells, junctional activity, nuclear atypia, necrosis, inflammation, cell proliferation, large intraepithelial, ulceration, stroma and the intravascular tumor cells followed. The proliferation index marked by Ki-67 was evaluated by means of immunohistochemistry while the mitotic index was assessed by staining with HE bleaching of melanin. With this study we can check that the proliferative index determined by counting mitoses and the immunohistochemical staining for the Ki-67 varied significantly between melanocytic tumors located in the oral cavity and skin, being that in the melanocytomas the proliferative index was much lower when compared with the melanomas. Also, the proliferative index showed a significant correlation with the nuclear atypia and the inflammation. The Ki-67 and the mitotic index showed to be statistically significant in both melanomas as well as in the melanocytic tumors in general, with the significant level of P=0.026 and P=0.001 respectively. Thus, the study of proliferative indices can be very useful for the diagnosis of canine melanomas and assisting the physician in choosing the best treatment.
Descrição
Dissertação de Mestrado em Biologia Clínica Laboratorial
Palavras-chave
Melanoma , Cão , Imunohistoquimica