Primary multifocal myxopapillary ependymoma of the filum terminale.

Background: Myxopapillary ependymoma (MPE) is a rare variant of ependymoma usually occurring in the conus medullaris or the filum terminale. It is usually a single encapsulated lesion. The aim of this study was to describe patients with primary multifocal MPE of the filum terminale.

Methods: In this retrospective study, medical records of 22 patients with spinal MPE who underwent surgical treatment in our hospital between January 2003 and January 2010 were enrolled. The study included 14 males and 8 females with age range from 11 to 66 years. There were 14 adult patients and 8 pediatric patients. The clinical presentation was low back pain (LBP), radiculopathy, focal neurological deficit and cranial nerve palsy.

Results: Four cases presented with primary multifocal MPE at the filum terminale. All of them had chronic LBP for at least 2-3 years. Three patients had lower extremity radiculopathy and one had urinary incontinence upon presentation. On magnetic resonance imaging (MRI), three patients presented with two lesions and one patient presented with three lesions at different spinal levels (a total of 9 MPEs). All lesions showed enhancement following gadolinium administration on MRI. For 6 tumors en bloc resection was performed. Three lesions were removed gross totally in a piece-meal fashion. Following the surgical management, no postoperative complication occurred. Three patients underwent radiotherapy (RT. On an average follow-up of 6 years with clinical and MRI imaging, no recurrence was detected and symptoms of LBP and neurologic findings improved after 2 months.

Conclusions: Primary multifocal MPE is an extremely rare event occurring in the conus medullaris or filum terminale. The exact pathogenesis of this condition is unclear. Multifocal MPE may be due to multifocal growth of tumors, early stage of growth of a giant tumor or drop metastasis of tumor in the subarachnoid space. En bloc resection or piecemeal resection with radiotherapy were associated with satisfactory outcome without recurrence.