Metástases de carcinomas mamários em linfonodos de cadelas : variáveis clínico-patológicas e estudo imunohistoquímico

Abstract

Canine mammary tumors (CMT) are the most common type of neoplasia in bitches. The presence of metastasis in regional lymph node is an important prognostic fator in bitches with mammary carcinomas. However, the clinical significance of isolated tumor cells (ITC) is still undefined. The efficacy of the Immunohistochemistry (IHC) in the identification of CTI and occult micrometastases in comparison to the conventional Hematoxylin Eosin (HE) technique was evaluated, as well the relation between tumor size, histological type, histological grade and presence of metastasis. Survival of bitches with occult CTIs was also evaluated. Fragments of mammary carcinoma and regional lymph nodes of 59 bitches were evaluated. Histological sections of the samples were evaluated for tumor diagnosis and tumor deposits and submitted to the IHC test using the pan-cytokeratin antibody AE1 / AE3. 35.2% of occult CTIs and 2.8% of occult micrometastases were detected by the IHC technique. There was a correlation between the size of the tumor and the presence of metastasis to the lymph node (p = 0.77). CTI were more frequently observed in the medullary region (60.7%) and metastases in the cortical region (44.4%). There was no statistically significant difference for overall survival curve Kaplan-Meier (Log rank (p = 0.466), Breslow (p = 0.171) and Tarone-Ware (p = 0.253) among bitches with occult CTIs and bitches with free lymph nodes. The IHC is able of detecting occult tumor cells. Bitchs with mammary carcinomas with ITC in the lymph node do not present lower survival.