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.