Carcinoma lobular pleomórfico da glândula mamária em humanos e caninos: abordagem clínico-patológica e imunofenotípica

Abstract

Mammary cancer is a disease that affects women worldwide, being the main cause of death in women in Brazil and in female dogs it is the most frequent neoplasm. Invasive lobular carcinoma are the second most common type of carcinoma in women, with pleomorphic lobular carcinomas representing 1% of the sample. In bitches, it was first described in 2002, showing morphological and immunophenotypic similarities with human CLP. Given the similarities of this neoplasm in female dogs with those described in women, its characterization is important for a better understanding of its behavior, seeking to enable the use of female dogs as a comparative model. For this purpose, 26 canine samples and 26 human samples were analyzed for clinical pathological data, and histopathological analysis together with immunohistochemical analyzes for HER2, RE, RP, E-cadherin and Ki-67 markers. The mean age found in canines was 9 years, while women had a mean age of 56 years, size T2 was the most frequent in both species, and in canines and women the most frequent histological grade was grade II. All canine CLPs were positive for RP and 96.1% were negative for RE and all cases were negative for HER-2 and E-cadherin. Women were positive for ER in all cases and 96.1% were positive for RP and 92.3% were negative for HER-2. The Luminal B subtype in canine was the most frequent molecular subtype, and in humans, the Luminal A and Luminal B subtypes had the same frequency.