Primary cutaneous malignant granular cell tumor: an immunohistochemical study and review of the literature.

Granular cell tumors (GCTs) are uncommon soft tissue tumors characterized by cytoplasmic granular appearance of the neoplastic cells. Malignant granular cell tumors (MGCTs) comprise less than 2% of GCTs and are mostly found in the subcutaneous soft tissues of the lower extremities, especially the thighs. Very few cases have been reported in the skin.