[Carcinoma arising from postburn scars (report of 5 cases)]

Carcinoma arising from postburn scars is rare. We have encountered 5 patients suffering from this late complication of scars, accounting for 0.32% of 1563 admissions for late surgery after burn injuries. They were all males, with a mean age of 56 years. The mean latent period was 43.2 years, and it was apparently longer when the acute burn injury occurred earlier in life. The site of predilection was the lower extremity, and multiple biopsies of various sites of the lesion remained to be the measure of confirmation. Pathologically, they were all squamoon cell carcinoma, grade I in 4 cases and grade II in 1. Immunohistochemical staining with anti-proliferation cell nuclear antigen (PCNA) showed that PCNA positive nuclei of squamous cell carcinoma were more numerous, as compared with that in the neighboring pseudo -epitheliomatous hyperplasia (PEH) and in normal skin, denoting markedly augmented assimilation of DNA in malignant degeneration. On the contrary, the number of Langerhan's cells were smallest in cancer area, as compared with PEH and normal skin. The diagnosis, treatment and prevention of such malignant degeneration in postburn scars have been discussed.