Clinical and Histopathologic Findings of Cutaneous Leiomyosarcoma: Correlation with Prognosis in 12 Patients.

INTRODUCTION Cutaneous leiomyosarcoma is a malignant neoplasm derived from smooth muscle cells. Its low incidence hampers the development of specific protocols for diagnosis and treatment. OBJECTIVES To describe the clinical and histopathologic characteristics of a series of primary and secondary cutaneous leiomyosarcomas and to determine how these characteristics correlate with prognosis. MATERIAL AND METHODS We performed an observational, descriptive, retrospective study based on 17 cutaneous leiomyosarcomas in 12 patients diagnosed between January 1, 2000 and December 31, 2015. We recorded demographic data, clinical and histopathologic characteristics, outcome, and response to treatment. RESULTS We included 5 men and 7 women, all aged more than 50 years at diagnosis. There were 4 cutaneous leiomyosarcomas (23%) in 4 patients, 2 subcutaneous leiomyosarcomas (11.5%) in 2 patients, and 11 skin metastases of leiomyosarcoma (65%) in 6 patients. The most frequently affected sites were the scalp (41%), lower limbs (17%), and trunk (17%). During follow-up, 50% of the cutaneous leiomyosarcomas recurred, 50% of the subcutaneous leiomyosarcomas presented distant metastases, and 83% of the patients with skin metastases of leiomyosarcoma died of their disease. LIMITATIONS Ours was a retrospective review of a small case series at a single center. CONCLUSIONS Cutaneous leiomyosarcoma is an uncommon malignant neoplasm. Our approach to diagnosis and therapy must take into account the marked heterogeneity in the prognosis of the various subtypes.