Squamous cell carcinoma on the lip arising from discoid lupus erythematosus: a case report and review of Japanese patients.

Squamous cell carcinoma (SCC) is a rare but well-recognized complication of longstanding discoid lupus erythematosus (DLE). Although few epidemiological studies concerning DLE-related SCCs in Japan exist, it has been estimated that the incidence of SCC arising in DLE lesions reaches 3.3%, which is similar to that reported for Caucasians (2.3% to 3.3%) [1, 2]. SCC is relatively rare in Japan, and its incidence of 2.5/100,000 person-years [3] is much lower than that in Caucasians (22.65/100,000 [...]