Mixed tumor of deep soft tissue

Mixed tumors of the salivary gland and skin are relatively common but are quite rare in soft tissue. It is believed that, as in the salivary gland form, most of these lesions are benign, but that a small subset behave in an aggressive fashion. We report here a patient with recurrent mixed tumor of soft tissue with infiltrative growth. The primary tumor arose in deep subfascial soft tissue of the right lower leg and was adjacent to the surface of the fibula. An open biopsy and complete resection were performed. Upon histological examination of the resected specimen, neoplastic cell infiltration at the tumor/soft tissue interface was not obvious; local recurrence, however, was observed 1 year later. The patient was treated with wide resection. Histological examination confirmed that the recurrent tumor with an extensive chondroid area invaded the osseous tissue of the fibula. At present, 1 year after the second resection surgery, there is no evidence of disease.