Adenomyoepithelioma of the breast: a cytologic dilemma. Report of a case and review of the literature.

Adenomyoepithelioma of the breast is a rare benign tumor made up of epithelial and myoepithelial cells. The cytologic features of this lesion are not well defined. This report describes the cytologic features of a case of adenomyoepthelioma characterized by hypercellularity and the presence of many atypical epithelial cells, leading to the erroneous diagnosis of adenocarcinoma. Review of the cytology literature shows that this condition frequently mimics the cytologic features of a number of benign and malignant breast lesions, thus representing not only an important potential pitfall in the diagnosis of carcinoma but also a differential diagnosis to consider in a variety of breast lesions. Copyright 2002 Wiley-Liss, Inc.