Adenoid cystic carcinoma of the breast: utility of immunocytochemical study with collagen IV on fine-needle aspiration.

A case of adenoid cystic carcinoma (ACC) of the breast in a 71-year-old woman is reported. This neoplasm accounts for about 0.1% of all breast cancers. The mammography showed a well-delineated mass without calcifications. Cytologic examination of percutaneous fine-needle aspiration (FNA) material gave the diagnostic of ACC, which was confirmed by histologic examination. This report emphasizes the utility of immunocytochemical study with collagen IV antibody on FNA material of this uncommon tumor.