Malignant myoepithelial tumor of soft tissue: a report of two cases of the lower extremity and a review of the literature.

Myoepithelial tumors of the soft tissues have only recently been described. Two cases of lower extremity malignant myoepithelial tumors are reported. One case of malignant mixed tumor overlying the gastrocnemius muscle was treated with wide local excision, but metastasized to regional lymph nodes 14 months after surgical excision. One patient with malignant myoepithelioma of the right lower leg was treated with limb amputation and is alive without disease at 46 months. A review of the literature discloses 120 additional cases of soft tissue myoepithelial tumors, 102 of which are myoepitheliomas and 18 are mixed tumors. Thirty-seven percent of the myoepitheliomas met the criteria for malignancy, and 33% of the mixed tumors were malignant. Of these, 30% had locally recurrent disease and 32% developed metastatic disease. Treatment benefit from chemotherapy and radiation therapy is unclear.