Malignant solitary fibrous tumor of the lumbar spinal root mimicking schwannoma: a case report

Background contextMalignant solitary fibrous tumors (SFTs) arising from the spinal cord are extremely rare and poorly understood mesenchymal neoplasms. To date, only one malignant SFT located in the spinal canal of the sacrum has been described, but none arising from the lumbar nerve root have been reported. Although most SFTs with benign histological features can be treated by complete surgical excision alone, malignant SFTs may require adjuvant therapy. However, systemic chemotherapy and radiotherapy have not been shown effective in patients with malignant SFTs.PurposeTo describe a patient with a malignant SFT arising from the lumbar nerve root.Study designA case report and review of literature.MethodsWe describe the clinical course of the patient and the radiological and pathological findings of the tumor. The effect of systemic chemotherapy was evaluated and the relevant literature was reviewed. This work has no disclosure of funding and was approved by the Institutional Review Board of Gifu University.ResultsThe tumor had been resected previously at another hospital, but it recurred and showed multiple metastatic lesions on both lungs within 3 months. Although the patient received systemic chemotherapy, both primary and metastatic lesions were found to be stable disease according to Response Evaluation Criteria in Solid Tumors. The patient died due to cachexia 6 months after her first visit.ConclusionThis patient presented with a highly unusual tumor. Even if a tumor is a dumbbell-shaped mass, similar to a neural tumor, SFT should be considered in the differential diagnosis.