[An extramedullary spinal cord tumor associated with syringomyelia: a case report].

A 53-year-old woman presenting weakness in the left hand for ten years was diagnosed seven years ago as having juvenile muscular atrophy of the unilateral upper extremity. Afterwards, her left forearm and hand gradually became weaker. A neurologist pointed out syringomyelia in the film of MR imaging. However, the cause of syringomyelia was not demonstrated until gadolinium-DTPA-enhanced MR imaging disclosed a spinal tumor. Through an operation it was found that it was an intradural extramedullary tumor at C7 level. Histological diagnosis of the tumor was meningioma. Only 12 reports of syringomyelia associated with extramedullary intraspinal tumors were found. Among them each tumor in three cases was diagnosed by delayed metrizamide computed tomography, only one case by MR imaging. Though in our case myelography, postmyelographic CT, intravenous enhanced CT and MR imaging were performed, gadolinium-DTPA-enhanced MR imaging was eventually most useful in diagnosing this tumor. The pathophysiologic mechanism by which the syrinx fills, and the differentiation in MR imaging between syrinx and tumor cyst were reviewed.