title: Benign proliferative nipple duct lesions frequently contain CAM 5.2 and anti-cytokeratin 7 immunoreactive cells in the overlying epidermis.
abstract: Benign proliferative nipple duct lesions (PNDLs) pose a diagnostic problem for clinicians and pathologists. Clinically, they may be associated with skin changes typically present in Paget's disease of the nipple. The identification of numerous scattered cells in the epidermis that are immunoreactive for low-molecular-weight cytokeratin may lead to further confusion with Paget's disease. We studied the nipple epidermis in nine cases of PNDL and compared them with 26 histologically normal nipples from mastectomy specimens. CAM 5.2 and anticytokeratin 7 (CK7) immunoreactive cells were identified in the epidermis of seven of nine nipples associated with PNDL. The cytokeratin-positive cells appeared cytologically benign and were dispersed singly (scattered in seven of seven cases and frequent in four of seven cases) or formed small aggregates with occasional tubular structures (three of seven cases) in the basal and middle layers of the epidermis. In two of seven cases, these epidermal immunoreactive cells showed continuity with the underlying PNDL, suggesting the spread or continuation of lesional cells to the epidermis. Dispersed single immunoreactive cells were identified in small numbers (scattered) in the basal layer of the epidermis in 12 of 26 normal nipples and more frequently in 1 of 12 cases. In all cases, the intraepidermal cells were negative for carcinoembryonic antigen (CEA) and Her-2/neu. We conclude that intraepidermal CAM 5.2 and anti-CK7 immunoreactive cells, which are normally present in the nipple epidermis, may proliferate and form aggregates when there is an underlying PNDL. The presence of these cells does not imply Paget's disease when the intraepidermal cells have a bland cytologic appearance, fail to overexpress Her-2/neu, and there is no carcinoma within the PNDL or elsewhere in the breast.
authors.affiliation: Department of Pathology, New York University School of Medicine, New York, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Zeng
authors.forename: J
authors.initials: J
authors.lastname: Melamed
authors.forename: P J
authors.initials: PJ
authors.lastname: Symmans
authors.forename: J F
authors.initials: JF
authors.lastname: Cangiarella
authors.forename: R L
authors.initials: RL
authors.lastname: Shapiro
authors.forename: H
authors.initials: H
authors.lastname: Peralta
authors.forename: W F
authors.initials: WF
authors.lastname: Symmans
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001941:Breast Diseases / Q000276:immunology / Q000473:pathology; D001943:Breast Neoplasms / Q000276:immunology / Q000473:pathology*; D002455:Cell Division; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7; D007633:Keratins / Q000276:immunology*; D008875:Middle Aged; D009558:Nipples / Q000276:immunology / Q000473:pathology*; D018300:Papilloma, Intraductal / Q000276:immunology / Q000473:pathology*; D012867:Skin / Q000276:immunology
chemical_list: D015415:Biomarkers; C400901:CAM 5.2 antigen; C507497:KRT7 protein, human; D053552:Keratin-7; D007633:Keratins