Cutaneous and subcutaneous leiomyosarcoma. A clinicopathologic study of 47 patients.

A retrospective study of 47 patients with leiomyosarcoma of superficial (skin and subcutaneous) soft tissue is presented. The criteria for the light microscopic diagnosis are given and the differential diagnoses are discussed. Forty patients had a solitary tumour which, in 19 patients, was situated entirely or almost entirely in the corium. There were two distinct growth patterns for the leiomyosarcomas. The cutaneous tumours were poorly delimited and the subcutaneous tumours more well-circumscribed or nodular. Some three quarters of the tumours were located in the extremities, the thigh and hip regions being the predilection sites; the highest frequency was noted in patients in their seventies; the ages ranged between 25 and 89 years. The sex ratio (male to female) was 2 to 1. In 37 patients follow-up information was available, the follow-up period ranging from 1 month to 16 1/2 years; the median time was 6 years. One or more local recurrences developed in 15 patients. Seven out of the 47 patients had multiple leiomyosarcomas; 4 of these patients had already been operated on for a retroperitoneal leiomyosarcoma. Fourteen patients in the whole series died with metastases especially in the lungs. Metastases were seen particularly in patients with subcutaneous and multiple leiomyosarcomas. Our study suggest that the size and the mitotic activity of the tumour appear to have some prognostic value. The initial surgical procedure was found to be the most important factor in influencing the outcome of the disease and it is stressed that leiomyosarcoma in superficial soft tissues should be treated by wide surgical excision. It is recommended that patients with multiple leiomyosarcomas in the superficial soft tissues should be subjected to further examination in order to exclude the possible occurrence of a retroperitoneal tumour. Finally, we consider that the use of a trichrome stain, such as the haematoxylin-van Gieson's stain, is superior to the haematoxylin-eosin stain in diagnosing leiomyosarcoma.