Sebaceous gland metaplasia in intraductal papilloma of the breast

We report here the first case of sebaceous gland metaplasia arising within an intraductal papilloma of the breast of a 70-year-old female. Several lob ules and nests composed of clear cells closely resembling sebaceous glands of the skin were discovered within an intraductal papilloma of the breast. Squamous metaplasia was also noted in certain areas of the tumor. Immunohis tochemically, the cells of the lobules and nests stained positively for mon oclonal antibodies anti-cytokeratin 14 and epithelial membrane antigen. Thi s study confirms a novel type of metaplasia of the breast.