Congenital Mobile Atlantoaxial Dislocation with Cervicomedullary Astrocytoma in Pediatric Patient.

Congenital mobile atlantoaxial dislocation with cervicomedullary astrocytoma has never been described. We present a case of a 7-year-old male child who presented to us with gradually progressive spastic quadriparesis following a fall from table. His lateral radiograph and magnetic resonance images showed mobile atlantoaxial dislocation with intramedullary heterogeneously enhancing cervicomedullary mass. The patient underwent suboccipital craniectomy with C1-4 laminectomy. Tumor was pinkish grey, tenacious with ill-defined plane and cyst at poles. C1-C2 fusion was done using C1 lateral mass and C2 pars screw and rod system with onlay bone graft. Histopathology revealed pilocytic astrocytoma. At the time of discharge, the patient showed improvement in spasticity. Postoperative lateral radiograph showed reduced atlantoaxial dislocation with stable construct.