Fine-needle aspiration biopsy of a case of breast carcinoma with choriocarcinomatous features.

Breast disease is of great concern to patients and health care providers alike. Malignancies of the breast and their various presentations can pose tremendous challenges with respect to early diagnosis and effective treatment. Carcinoma of the breast may appear in several forms and produce one or more ectopic substances. Breast carcinomas that display choriocarcinomatous differentiation and produce human chorionic gonadotropin are very rare. Less than a dozen such cases have been described in the medical literature to date. We report a case of breast carcinoma with choriocarcinomatous features, which is the first to show immunohistochemical evidence of the expression of both estrogen receptor and progesterone receptor. We also discuss the cytopathologic aspects observed and conduct a literature review.