Dorsal intramedullary dermoids.

We report a case of a 31-year-old woman with an intramedullary thoracic dermoid, who had progressive spastic paraparesis in her lower extremities over a period of three years, as well as loss of bowel and bladder control. She had been operated for "spina bifida" at three days of age but had no neurologic deficit. MRI of the thoracic spine showed an intramedullary hypointense lesion at T7-T8, associated with an intramedullary lipoma at a higher level. Intracapsular resection of an intramedullary dermoid cyst was performed. We review the literature on intramedullary dermoids differentiating them from the more common, but still rare, lumbosacral subdural juxtamedullary dermoids. We discuss the associated malformations with these lesions, as well as their pathophysiology and treatment. Although uncommon, dorsal intramedullary dermoids should be suspected and treated in a timely manner, especially in presence of other congenital anomalies.