Primary mammary mucinous cystadenocarcinoma: cytological and histological findings.

Mucinous cystadenocarcinoma (MCA), commonly encountered in the ovary or pancreas, is rare in the breast and was only recently described as a distinct variant of invasive ductal carcinoma of the breast. Only 11 cases of primary mammary MCA have been reported. In this article, we report a case of primary mammary MCA with focus on cytological and histological findings.