title: Synchronous primary perianal Paget's disease and rectal adenocarcinoma: report of a hitherto undescribed phenomenon.
abstract: Perianal Paget's disease is rare. It usually represents intraepidermal extension of an invasive carcinoma from an adjacent internal organ, but some cases represent primary intraepithelial cutaneous apocrine adenocarcinomas. Here, we report a unique case, which we interpret as synchronous primary perianal Paget's disease and lower rectal adenocarcinoma. Immunohistochemical stains demonstrated that the Paget's cells were CK7+/ CK20-/GCDFP+, whereas the rectal adenocarcinoma was CK7+(variable)/CK20+/GCDFP-. This discordant immunoprofile supported our impression that the Paget's disease in this patient was of cutaneous apocrine origin rather than a pagetoid extension from the patient's nearby rectal adenocarcinoma-to our knowledge a hitherto undocumented occurrence.
authors.affiliation: Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.lastname: Chanjuan Shi
authors.forename: Pedram
authors.initials: P
authors.lastname: Argani
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D000368:Aged; D001003:Anal Canal; D002352:Carrier Proteins / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D053554:Keratin-20 / Q000378:metabolism; D053552:Keratin-7 / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D010145:Paget Disease, Extramammary / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D053554:Keratin-20; D053552:Keratin-7; D026901:Membrane Transport Proteins; C488892:PIP protein, human