导管内乳头状瘤，伴大汗腺化生

Foci of apocrine metaplasia are not uncommon in papillomas, and rarely most or all of the epithelium is of the apocrine type. When present in the conventional papillary configuration, apocrine metaplasia is usually cytologically bland, but apocrine atypia manifested by nuclear pleomorphism and cytoplasmic clearing is likely to be encountered in sclerosing papillary tumors. This is especially common when sclerosing adenosis is incorporated into a papilloma （Rosen's Breast Pathology, 3rd Edition）