Background: Cutaneous leiomyosarcoma is a rare dermal neoplasm usually arising from the pilar smooth muscle. It is considered a relatively indolent neoplasm, and there is debate whether designation as sarcoma is appropriate. Owing to some conflicting data in the literature, however, its behavior warrants further clarification.
Objective: To determine the clinical behavior and demographic and pathologic characteristics of cutaneous leiomyosarcoma.
Materials and methods: The Surveillance, Epidemiology and End Results database was used to collect data on cutaneous leiomyosarcoma and 2 reference populations: cutaneous angiosarcoma (aggressive) and atypical fibroxanthoma (indolent). Demographic and oncologic characteristics were examined, and overall survivals (OS) and disease-specific survivals were compared.
Results: Leiomyosarcoma and atypical fibroxanthoma displayed lower stage (localized: 69.7% and 66.8% respectively), smaller size (<3 cm: 90.5% and 72%), and lower rates of disease-specific mortality (2.9% and 7.8%) compared with angiosarcoma. Patients with leiomyosarcoma had a 5-year disease-specific survival rate of 98% and OS rate of 85%.
Conclusion: Cutaneous leiomyosarcoma shows outcomes similar to atypical fibroxanthoma. It is nearly always indolent and should be distinguished from more aggressive cutaneous and subcutaneous sarcomas. Clear communication of the biologic potential may be best achieved using alternate diagnostic terminology such as "atypical intradermal smooth-muscle neoplasm."