Metastatic Alveolar Soft Part Sarcoma of the Spinal Cord: A Case Report and Review of Literature.

Abstract

Alveolar soft part sarcoma (ASPS) is a rare, malignant soft-tissue neoplasm typically seen in young adults that possesses an unusual tendency to metastasize. Metastases to the intramedullary compartment of the spinal cord, however, are exceptionally rare and have not been described in the literature. We report the case of a 23-year-old woman with disseminated ASPS to the lung and brain who presented with progressive lower-extremity weakness and loss of sensation after radiation and chemotherapy. Magnetic resonance imaging revealed a 1.3-cm avidly enhancing lesion within the central thoracic spinal cord at T3. A T2-T4 laminectomy was undertaken and resulted in a gross total resection. Histopathologically, the mass was composed of organoid nests containing epithelioid cells with eosinophilic, granular cytoplasm separated by sinusoidal spaces. Immunohistochemistry demonstrated convincing positive TFE3 staining. Postoperative imaging confirmed the complete resection of the mass, and her examination was notable for intact sensation and impaired motor function that gradually improved. A review of the literature found that the reported case represents the first instance of primary or metastatic ASPS in the spinal cord. Metastatic ASPS should thus be included in the differential diagnosis in patients with known disease and neurologic impairment or back pain. Imaging of the spine should then be considered.