Intraductal lipid-rich carcinoma of the breast with a component of glycogen-rich carcinoma.

We report a rare case of intraductal lipid-rich carcinoma of the breast with a component of glycogen-rich carcinoma. An impalpable tumor that was revealed by mammography and magnetic resonance imaging was excised. Histologic examination showed vacuolated neoplastic cells in the mammary ducts, and electron microscopy confirmed lipid droplets in the cytoplasm. The coexistence of glycogen-rich carcinoma was shown. Lipid-rich carcinoma that is coexistent with glycogen-rich carcinoma is rare, and most lipid-rich carcinomas are invasive. Intraductal lipid-rich carcinoma is difficult to detect without echography or mammography.