Primary leiomyosarcoma of the skin: 32 cases

Background. Superficial leiomyosarcomas are rare tumors, which may be confi ned to the dermis or extend to subcutaneous tissues. Patients and methods. We report the results of a retrospective study of 32 patients treated for leiomyosarcomas through a twenty-two year period (from 1975 to 1997). Results. Mean age war 45 years, with 50 p. too of patients less than 35 yea rs of age. Forty seven percent of the tumors were located on the lower limb s and mean diameter was 2.8 cm. Three clinical types have been isolated: no dule beneath normal epidermis (50 p. 100), purple nodule ulcerated or not ( 28 p. 100), swelling tumor (22 p. 100). Sixteen percent were intradermal, w hereas sixty nine percent involved subcutaneous tissues. With regard to tum or grade. 37 p. 100 of tumors were grade I, 44 p. 100 of tumors were grade II, and 19 p. 100 were grade III. Immunohistochemical staining showed posit ive reactions for all tumors with anti-vimentin and anti-alpha smooth muscl e actin. Main treatment was complete surgical excision. Follow-up informati ons were available for all patients and 75 p. 100 of them had a follow up p eriod longer than a year. Five patients with leiomyosarcomas involving the subcutis developed local recurrences, and two of them died of the disease. Discussion. Leiomyosarcomas can occur at any age without predominant sex-ra tio. Main prognostic factors are tumor size, distal location, depth of tumo r invasion and pathological grade. Immunohistological staining with anti-al pha smooth muscle actin is more sensitive and specific than with anti-desmi n or anti-HHF 35. Main treatment is surgical excision with wide margins.