Epidermoid carcinoma and perforating necrobiosis lipoidica: a rare association.

We report the case of a 33-year-old patient who had had insulin-dependent diabetes mellitus (IDDM) since he was 11 months old, and who presented with major perforating necrobiosis lipoidica (PNL) complicated by a well-differentiated epidermoid carcinoma. PNL is a rare clinical form of NL, always associated with diabetes. Only seven cases have been reported to date in the literature, and to the best of our knowledge, an association of epidermoid carcinoma and PNL has never been described. The development of a tumoral transformation on a classical NL plaque has only been described 12 times. The presence of an epidermoid carcinoma on a weakened background with permanent ulceration suggests that early surgical excision of the tumour and of the NL followed by a skin graft might be the treatment of choice. Radiotherapy seems to be a poor therapeutic option.