Primary cutaneous and subcutaneous leiomyosarcomas: evolution and prognostic factors.

Cutaneous and subcutaneous leiomyosarcomas (LMS) are uncommon neoplasms. We reviewed the MEDLINE database to assess their rates of recurrence and metastasis, mortality and recommended follow-up period. Other prognostic factors were also studied. This review included 112 subcutaneous LMS and 313 cutaneous LMS. In subcutaneous LMS, we observed that rates of recurrence, metastasis and mortality were 36.63%, 43.23% and 37.82%, respectively, after a median follow-up period of 4.40 years, while in cutaneous LMS those figures were 24.40%, 4.22% and 3.33%, respectively, after a median follow-up period of 3.45 years. Although subcutaneous and cutaneous LMS show similar morphologic features, the latter show less tendency to recur and metastasize; in certain cases they both may be the cause of death. For these reasons we suggest avoiding the term "atypical intradermal smooth muscle neoplasm". Location, size and histologic grade are essential prognostic factors for superficial LMS. Recurrence after incomplete excision can be avoided when performed with a surgical margin of at least 1 cm. Follow-up should be at least five years.