Abstract
INTRODUCTION: Primary skin leiomyosarcomas are infrequent neoplasms. They correspond to 2-3% of skin sarcomas and are most frequently located on the lower extremities, trunk and genitals. METHODS: We present a case of a 73-year-old man with a 4-month evolution of foreskin leiomyosarcoma. The lesion was biopsied for histopathological study with HE and immunohistochemistry with smooth muscle actin, specific muscle actin, CD34, p63 and S-100 (-). RESULTS: We observed a leiomyosarcoma of high histological grade and mitotic count. It was positive by immunohistochemistry for smooth muscle actin, while the other markers were negative. Surgical limits were compromised so a reoperation with wide margins of healthy tissue was necessary. CONCLUSION: The skin lesions should be removed all, without exception, since they can be neoplasms of variable biological behavior. The histological study must be complemented with immunohistochemistry to differentiate them from other neoplasms. For the prognosis, the histological grade, size, location and the possibility of resection with wide margins must be taken into account.