[Recurrent aseptic meningitis caused by rupture of a pineal cyst]

A 40-year-old woman experienced three attacks of aseptic meningitis in 19 months. Each attack was characterized by sudden onset of meningeal irritation followed by spontaneous remission in several days. The patient was free of neurological symptoms between the attacks. In the acute phase of each attack, her cerebrospinal fluid (CSF) showed mononuclear pleocytosis and increased protein concentration. Epithelial cell clusters in the CSF were evident during the third episode. No pathogenic microorganisms were identified in CSF or blood cultures. Brain imaging revealed a pineal cyst, 1 cm in diameter, and we suspected that the epithelial cell clusters represented the ruptured cystic wall and that the recurrent aseptic meningitis was triggered by spontaneous rupture of the cyst. Recently several new etiologies for the benign recurrent aseptic meningitis (Mollaret's meningitis) have been reported, but its existence as a clinical entity is still in dispute. Our case appears to support "spontaneous rupture of central nervous system epidermoid cysts" as one of the etiologies of recurrent aseptic meningitis.