Spinal intramedullary arachnoid cyst.

Spinal arachnoid cysts are a relatively uncommon lesion. They may be either intra or extradural; intradural cysts being less common. Symptomatic spinal arachnoid cysts in the pediatric age group are rare. To the best of our knowledge only 2 cases of intramedullary arachnoid cysts have been reported to date. We report an unusual case of intramedullary cyst diagnosed in a 10-year-old female who presented with progressive quadriparesis. MRI scans revealed an intramedullary cystic lesion from C4 to T2. She underwent a C3 to T2 laminectomy with partial excision of the cyst. Histopathological findings confirmed the diagnosis of an arachnoid cyst. Postoperatively the patient showed dramatic recovery with marked improvement in neurological status. Arachnoid cysts should be considered in the differential diagnosis of progressive quadri / paraparesis in the pediatric age group as surgical decompression leads to marked improvement in the symptoms.