Mammary carcinoma with osteoclast-like giant cells: a study of four cases and a review of literature.

Mammary carcinoma with osteoclast-like giant cells (OGCs) is an extremely rare tumor. To the best of our knowledge, only 45 cases have been reported in the literature. Here we report four additional cases of this tumor. The fine-needle aspiration cytology was performed in all four cases, showing an abundance of giant cells and mononucleated stromal cells in intimate association with low- or medium-grade malignant epithelial clusters. Histologically, cribriform patterns predominated in three cases. In one case, OGCs were more pronounced in the vicinity of ductal carcinoma in situ accompanied by marked stromal angiogenesis. This study, as well as review of the literature, underlines the characteristic features of this rare histologic type of carcinoma. Copyright 2005 Wiley-Liss, Inc