Arachnoid cysts: unusual aspects and management.

Several unusual aspects of primary cerebral arachnoid cysts are presented. The optimal management of these lesions is discussed. Attempts at craniotomy and excision of these cysts is not always effective in eliminating the lesion and may provoke intracranial catastrophies. Huge and bilateral cysts are best treated by cystoperitoneal shunting. In general shunting may be preferable to craniotomy and resection of the cyst. An anti-siphon device is recommended to avoid overdrainage of cerebrospinal fluid.