Basosquamous carcinoma-an under-recognized, high-risk cutaneous neoplasm: case study and review of the literature.

Basosquamous carcinoma of the skin is a relatively rare cutaneous neoplasm that has been shown to have significant metastatic potential. Histopathologists debate whether these lesions arise de novo or differentiate from pre-existing basal cell carcinomas. We present a case in which a longstanding lesion initially diagnosed as basal cell carcinoma was later found to have basosquamous histology and regional metastases. Review of the literature reveals a metastatic rate greater than that of basal cell and squamous cell carcinoma, and identifies several important characteristics that impact prognosis after surgical resection. For physicians treating carcinomas of the skin, it is important to understand the natural history and proper treatment of this aggressive neoplasm.