Fine needle aspiration cytology of mammary carcinoma with choriocarcinomatous features: a report of 2 cases.

Background: Neoplasms of the breast containing multinucleated giant cells (MGCs) include both benign and malignant entities, such as benign soft tissue giant cell tumors, atypical fibrous histiocytoma, sarcomas, metaplastic carcinomas and the uncommon carcinomas containing osteoclast-like giant cells (OGC). Breast carcinoma with choriocarcinomatous features (BCCF) is a distinct variant of breast cancer.

Cases: We report the cytologic features, pathologic findings and immunohistochemical profile in 2 cases of this unusual variant of breast carcinoma. Two women aged 53 and 50 years women presented with a history of left and right breast lump but no local lymphadenopathy, respectively. Fine needle aspiration cytology (FNAC) of both cases revealed abundant MGC with highly pleomorphic tumor cells in the hemorrhagic necrotic background. Both of the cases were histopathologically diagnosed as BCCF.

Conclusion: Choriocarcinomatous differentiation with multinucleated syncytiotrophoblast-like giant cells is extremely rare in breast tumors. Although rare, FNAC of breast cancer with pleomorphic MGC requires careful search for differential diagnosis; breast carcinoma with giant cell features (choriocarcinomatous features, OGC features) must be differentiated from metastatic tumors and other breast lesions containing giant cells.