Leiomyosarcoma of the skin: Clinical, histopathologic, and prognostic factors that influence outcomes

Background: Superficial leiomyosarcoma (LMS) is a rare tumor with important clinical, pathologic, and treatment features. Previous LMS studies have included few patients, included minimal follow-up, and typically combined the superficial and subfascial (deep) forms. Objective: We sought to characterize clinical features, effectiveness of treatment approaches, and longterm outcomes for LMS stratified by depth of invasion. Methods: In all, 71 cases of primary superficial LMS, 48 dermal and 23 subcutaneous (mean follow-up of 8 years), were examined and clinical, histopathologic, and treatment factors reported. Results: Tumor size and subcutaneous classification correlated with greater likelihood of metastasis and death at 5 years. When superficial LMS metastasizes, other skin sites are the most common distant location. Treatment with wide local excision with minimum 1-cm margins showed statistically lower rates of recurrences and metastasis compared with excision with narrow surgical margins. Fourteen cases of Mohs micrographic surgery had no recurrences or metastases. Five cases of dermal LMS metastasized, 2 of which resulted in death. Limitations: This study is a retrospective review of a relatively small number of patients. Conclusion: LMS can metastasize and warrants surgical intervention and long-term follow-up. Wide local excision, and Mohs micrographic surgery in particular, appear to provide the best management approach for definitive treatment.