Squamous cell carcinoma complicating late chronic discoid lupus erythematosus.

Two cases of squamous cell carcinoma developing in lesions of chronic cutaneous discoid lupus erythematosus are presented. One of the patients was white and the other was black. The squamous cell carcinoma in the black patient proved to be rapidly metastatic and eventually fatal. The white patient developed seven squamous cell carcinomas over 8 years with no evidence of metastatic spread. The role of ultraviolet light in inducing skin cancer in these patients is discussed.