[Primary cutaneous leiomyosarcoma: 32 cases]

Superficial leiomyosarcomas are rare tumors, which may be confined to the dermis or extend to subcutaneous tissues.

We report the results of a retrospective study of 32 patients treated for leiomyosarcomas through a twenty-two year period (from 1975 to 1997).

Mean age was 45 years, with 50 p. 100 of patients less than 35 years of age. Forty seven percent of the tumors were located on the lower limbs and mean diameter was 2.8 cm. Three clinical types have been isolated: nodule beneath normal epidermis (50 p. 100), purple nodule ulcerated or not (28 p. 100), swelling tumor (22 p. 100). Sixteen percent were intradermal, whereas sixty nine percent involved subcutaneous tissues. With regard to tumor 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 positive reactions for all tumors with anti-vimentin and anti-alpha smooth muscle actin. Main treatment was complete surgical excision. Follow-up informations were available for all patients and 75 p. 100 of them had a follow up period longer than a year. Five patients with leiomyosarcomas involving the subcutis developed local recurrences, and two of them died of the disease.

Leiomyosarcomas can occur at any age without predominant sex-ratio. Main prognostic factors are tumor size, distal location, depth of tumor invasion and pathological grade. Immunohistological staining with anti-alpha smooth muscle actin is more sensitive and specific than with anti-desmin or anti-HHF 35. Main treatment is surgical excision with wide margins.