[Adenoid cystic carcinoma of the breast--a case report].

We report a rare case of adenoid cystic carcinoma (ACC) of the breast. The patient was a 60-year-old female with a lump of the left breast which had present for 20 years. Macroscopically, the resected left breast tumor was well defined, 7.5 X 7 X 5 cm in size, oval shaped, yellowish gray-white and solid, parts of the tumor showed cystic appearance. Microscopic study revealed a cribriform pattern and alveolar proliferation of uniform, small cells forming cysts, and duct-like spaces which contained mucous content. Each tumor nest was surrounded by hyaline stroma. Alcian blue-PAS staining showed that the cysts were alcian blue-positive; the ducts were PAS-positive. The tumor was diagnosed as ACC of the breast.