Malignant granular cell tumor of the multifidus muscle: Case report and review of the literature

Granular cell tumors (GCTs) are uncommon soft tissue tumors characterized by cytoplasmic granular appearance of the neoplastic cells. Malignant GCTs comprise less than 2% of GCTs and are mostly found in the subcutaneous soft tissues of the lower extremities, especially the thighs. This report presents a case of malignant granular cell tumor in the right multifidus muscle. A 69-year-old woman presented to the surgeon with a 3 month history of light pain in the lumbar area and hip joint, with no particular history. CT and MRI revealed a soft tissue tumor with a maximum diameter of 7.5 cm. There is patchy unenhanced hypointense shadow in the mass. Widely excision was performed for the primary tumor, which was interpreted as an malignant GCTs. GCTs should be considered in the differential diagnosis in a rapidly growing intramuscular tumors. We investigated the CT and MRI findings of malignant granular cell tumor.