Intramedullary neurenteric cyst with a false mural nodule: case report.

Spinal neurenteric cysts are rare congenital lesions that may occur either alone or in the context of a complex malformative disorder including typical vertebral and cutaneous abnormalities. The interest of the case of a spinal neurenteric cyst described here lies in its rare intramedullary location and in the false mural nodule image on the preoperative magnetic resonance imaging scan. A further distinctive feature is the association with a cleft spinal cord. A 28-year-old woman presented with a 2-year history of progressive paraparesis and urinary retention. A magnetic resonance imaging study disclosed a T8-T9 intramedullary cystic lesion with a mural nodulelike formation on the posterior face. A posterior midline myelotomy exposed a cystic lesion that had translucent walls and contained a milky fluid. No mural nodules were found. Once the cyst had been emptied, a collateral finding was a cleft that was clearly observed in the anterior spinal cord. The histological diagnosis was a neurenteric cyst. Retrospectively, the nodular lesion found on the preoperative scan was attributed to mucinous clots deposited at the bottom of the cyst. This case report demonstrates that neurenteric cysts can vary widely in radiological appearance, depending on the contents of the cyst. These differences become especially important if the associated stigmata are lacking and the preoperative diagnosis rests on magnetic resonance imaging scan appearance alone.