Extraordinary Case ReportCutaneous Metaplastic Carcinoma: Report of a Case With Sebaceous DifferentiationPazzini, Renato MD*; Pereira, Gustavo A. MD†; Macarenco, Ricardo S. MD†,‡Author Information *Department of Dermatology, Hospital Alemão Oswaldo Cruz, São Paulo, Brazil; †Department of Dermatology, Instituto do Câncer do Estado de São Paulo Octavio Frias de Oliveira (ICESP), São Paulo, Brazil; and ‡Department of Pathology, Hospital Israelita Albert Einstein, São Paulo, Brazil. Correspondence: Ricardo S. Macarenco, MD, Department of Pathology, Hospital Israelita Albert Einstein, Av Albert Einstein, 627 Morumbi, São Paulo 05652-900, Brazil (e-mail: [email protected]). The authors declare no conflicts of interest. The American Journal of Dermatopathology: July 2018 - Volume 40 - Issue 7 - p e100-e103 doi: 10.1097/DAD.0000000000001070 Buy Metrics Abstract In this study, a case of a 56-year-old woman with cutaneous metaplastic carcinoma in the neck is reported. It harbored basal cell carcinoma, squamous cell carcinoma, and sebaceous carcinoma, as well as osteosarcoma (with fibroblastic, osteoblastic, aneurysmal bone cyst-like, and chondroblastic patterns). To our knowledge, the literature does not mention sebaceous carcinoma in cutaneous metaplastic carcinoma. Epidemiology and intact mismatch repair proteins of this case support sporadic pathogenesis for this neoplasm. The patient has been followed up for 3 years after surgery with free margins, and no local recurrence or distant metastases have been observed. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.