Primary leiomyosarcoma of the skin. A histological and immunohistochemical analysis.

We report a rare case of a cutaneous leiomyosarcoma on the extensor surface of the proximal part of the left arm of an 84-year-old man. The tumour exhibited a number of histological and immunohistochemical features which are characteristic of a leiomyosarcoma. Leiomyosarcomas are frequently misdiagnosed on clinical grounds. Therefore, clinical features, differential diagnosis, histological and immunohistochemical criteria, therapy and prognosis of this rare malignant tumour are summarized on the basis of the present case and previously published reports.