RESUMO
Inflammatory mammary carcinoma (IMC) is a unique form of mammary cancer that affects women and female dogs. Hallmarks of IMC include clinical signs of inflammed affected glands and invasion of dermal lymphatics by tumor cells. Due to locally aggressive behavior and high metastatic rate, prognosis is considered poor. No satisfactory treatment has been suggested in veterinary medicine. The goal of this study was to evaluate the immunoreactivity for estrogen and progesterone receptors and cell proliferative indexes in nine cases of canine IMC. Estrogen and progesterone receptors were negative in all cases. For cell proliferative indexes, the mean number of neoplastic cells staining positive for Ki-67 and PCNA were 4.47% and 20.81%, respectively. Lack of estrogen and progesterone receptor expression, suggesting an undifferentiated phenotype, in conjunction with a relatively high proliferative capacity reflected by Ki-67 and PCNA staining are features typical of many clinically aggressive neoplasms, including canine IMC.