Plaque-like leiomyomas on a chemical burn: First case report

Cutaneous leiomyomas are uncommon benign smooth muscle neoplasms of skin of unknown pathogenesis. We report a sporadic case of multiple cutaneous leiomyomas at the site of a chemical burn. A 47-year-old male presented with multiple grouped red nodules on the right calf painful to cold and to touch. The lesions were located on the site of a chemical wound that had occurred 5 years earlier. Histopathological examination revealed a proliferation of smooth muscle fibres, leading to diagnosis of leiomyoma. To our knowledge, the literature contains no previous reports of sporadic multiple cutaneous leiomyomas occurring at a chemical burn site. While a chance association cannot be ruled out, there is also the possibility of a physiopathological mechanism similar to that of vascular tumours following exposure to 4-hydrazinobenzoic acid. This compound, a hydrazine derivative of the fungus Agaricus bisporus, can cause smooth-muscle tumours in the aorta and large vessels with morphological characteristics similar to those seen in vascular leiomyomas.