title: A unique case of squamous cell carcinoma showing adenocarcinomatous features with focal apocrine differentiation.
abstract: We report an 85-year-old man with squamous cell carcinoma on the right pinna. Two years after the excision of the lesion, metastatic foci were found extending from the right retromandibular to the mastoid region and into the parapharyngeal space. Histopathologically, the primary tumor showed interconnecting nests of atypical cells invading into the dermis from multiple epidermal and infundibular foci. The tumor had both squamous and glandular differentiation. A peculiar finding was the presence of decapitation secretion in the glandular foci. To our knowledge, definite apocrine differentiation in squamous cell carcinoma has not previously been reported.
authors.affiliation: Department of Dermatology and Occupational Dermatopathology, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Yasuda
authors.forename: M
authors.initials: M
authors.lastname: Murayama
authors.forename: M
authors.initials: M
authors.lastname: Asahi
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D001050:Apocrine Glands / Q000378:metabolism / Q000473:pathology*; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology* / Q000556:secondary; D002454:Cell Differentiation; D004428:Ear Neoplasms / Q000473:pathology*; D004431:Ear, External / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000556:secondary; D006801:Humans; D007633:Keratins / Q000032:analysis; D008297:Male; D008416:Mastoid / Q000473:pathology; D009361:Neoplasm Invasiveness; D010610:Pharyngeal Neoplasms / Q000556:secondary; D012878:Skin Neoplasms / Q000473:pathology*; D012888:Skull Neoplasms / Q000556:secondary
chemical_list: D002272:Carcinoembryonic Antigen; D007633:Keratins