[Thoracic solitary neurenteric cyst--case report].

A 61-year-old man presented with repeated back pain and progressive anesthesia of both lower limbs. MR images and myelography showed an intradural, extramedullary tumor at the Th8-9 level. Surgery revealed a thin membrane containing xanthochromic cerebrospinal fluid behind the spinal cord. Microscopically, the excised lesions contained columnar epithelium with goblet cells. Spinal neurenteric cysts are a rare anomaly, especially solitary cysts located in the thoracic spine. The neurenteric canal transiently develops in the lumbosacral region during the 3rd week of gestation. Thus, it is difficult to claim that the neurenteric cyst in our case originated in a remnant of the neurenteric canal. As Bentley and Smith (1960) suggested, thoracic solitary neurenteric cysts may develop from a remnant of adhesion between ectoderm and endoderm during the 3rd week of gestation as a result of splitting of the notochord.