Varying characteristics of subcutaneous and dermal leiomyosarcomas. Two case reports and literature review

Cutaneous leiomyosarcomas (LMS) originating from smooth muscle of the skin are rare malignant neoplasms. Preferential sites are hair-bearing areas, especially the legs. We report two patients in their 5th and 7th decade, in whom leiomyosarcomas were encountered in the lower leg and the capillitium, respectively. Histologically, the former was found to be a dermal leiomyosarcoma with subcutaneous infiltration, the latter an exclusively dermal tumor. The LMS of the lower leg had been excised three years previously in a different institution and had been diagnosed as a leiomyoma. Both lesions were excised with adequate safety margins in our institution and within a two-year postoperative observation period no recurrences were encountered. Dermal leiomyosarcomas have a 33% recurrence rate while that of subcutaneous leiomyosarcomas show is 50%. In contrast to exclusively dermal tumors, subcutaneous LMS show a tendency for hematogenic and lymphogenic metastases. Therapy of choice is excision with wide safety margins.