A hemorrhagic pineal cyst with a bacterial meningitis-like manifestation and benign outcome.

Pineal cysts are a common incidental finding in imaging studies, and the majority of such cysts are asymptomatic. However, hemorrhaging pineal cysts, which are considered to be rare, are often associated with severe symptoms. We herein describe the case of a 58-year-old patient with the novel manifestation of a bleeding pineal cyst, who had a benign outcome without any surgical treatment. Although the clinical manifestations resembled those of bacterial meningitis, magnetic resonance images suggested chemical meningitis caused by an intracystic hemorrhage and rupture of the pineal cyst.