Spinal intradural cystic venous angioma originating from a nerve root in the cauda equina

A spinal intradural extramedullary venous angioma is extremely rare and has not been previously reported. In this paper, the authors report on this entity with morphological and immunohistochemical evidence, and discuss the surgical strategy for its treatment. A 54-year-old woman presented to Nagoya University Hospital complaining of left-sided pain in the hip, thigh, and inguinal and perianal regions, with progressive worsening during the previous 2 weeks. Lumbar spine MRI showed an intradural extramedullary cyst at the level of T12-L1, which extended from the conus medullaris to the cauda equina. The cyst wall was not enhanced on T1-weighted MRI with Gd. Intraoperatively, a midline dural opening allowed the authors to easily visualize a dark-reddish cyst behind the spinal nerve rootlets in the cauda equina adjacent to the conus medullaris. The cyst was believed to originate from one of the spinal nerve rootlets in the cauda equina and a cluster of veins was identified on the cyst wall. The cyst was resected with the affected nerve rootlet. The surgery left no detectable neurological deficit. Based on the morphological and immunohistochemical evidence, the lesion was diagnosed as a venous angioma. No tumor recurrence was confirmed based on MRI at the time of the 2-year follow up. This is the first report of an intradural extramedullary cystic venous angioma that was successfully resected.