Malignant granular cell tumors (MGCTs) are very rare soft tissue sarcomas. Definite criteria for pathologic diagnosis and the optimal treatment strategy have not been fully established. Here, we describe a 76-year-old woman with a huge MGCT in the right gluteal region, who developed a local recurrence and died from that tumor 14 months after undergoing an operation for the primary tumor. Although microscopic examination revealed that round and granular tumor cells staining for S-100 protein were dominant, components of the spindle cell sarcoma reacting with alpha smooth muscle actin were partially observed. MGCT is believed to originate from Schwann cells; however, pathologic findings in our case showed both Schwannian and non-Schwannian features. This is the first report on MGCT with these 2 features appearing simultaneously.