Primary diffuse cerebral leptomeningeal atypical teratoid rhabdoid tumor: report of the first case.

Atypical teratoid rhabdoid tumor (AT/RT) of the central nervous system has been recently described as a distinct clinicopathological entity with characteristic morphologic, immunophenotypic and molecular characteristics. AT/RT typically involves the posterior fossa of the pediatric population. Supratentorial AT/RT is exceedingly rare. In this report, we describe a very unusual case of a child who presented with signs and symptoms suggestive of leptomeningitis. However, imaging studies and histologic findings showed plaque-like AT/RT involving the leptomeninges of the cerebrum, cerebellum, and spinal cord. The disease proved to be rapidly fatal and resulted in the patient's death within approximately two weeks. To our knowledge, this is the first case of primary leptomeningeal AT/RT involving the supratentorial leptomeninges.