CLINICOPATHOLOGICAL ANALYSIS OF INVASIVE MICROPAPILLARY CARCINOMA OF THE BREAST

Abstract

Invasive micropapillary carcinoma (IMC) is a rare variant of invasive ductal carcinoma having a high frequency of lymphnode metastasis and a poor prognosis. We treated 7 such cases surgically in the last 2 years. We compared clinocopathological features in these cases, and evaluated the expression of ER, PgR, c-erbB2, E-cadherin and β-catenin immunohistochemically. A high incidence of axillar lymphnode metastasis was found. Aspiration biopsy cytology was done and in most cases Papanicolaoustained smears showed papillary structured cell clusters without a fibrovascular core. This may be a helpful feature for preoperatively diagnosing of IMC. The positive rates of ER and PgR were 71% and 57%, and 71% of cases were judged c-erbB2 positive (++/+++). All cases were E-cadherin and β-catenin positive, but these molecules were not expressed outside micropapillary clusters.