Background: The radiographic identification of pineal cysts has increased dramatically within the last two decades due to the advent of magnetic resonance imaging. Pineal cysts are often found incidentally with only a minority of these lesions ever becoming symptomatic and requiring treatment. Many theories attempting to explain the pathogenesis of these cysts exist.
Methods: We describe a case of a 12-year-old girl who presents with a pineal hemorrhage of unknown etiology with associated hydrocephalus.
Results: Her hydrocephalus was initially treated with an external ventricular drain followed by a third ventriculostomy. She had no evidence of elevated beta human chorionic gonadotropin or alpha-fetoprotein within the serum or cerebrospinal fluid. Follow-up imaging at seven weeks revealed resolution of her hemorrhage, however, there was development of a progressive cystic lesion within the pineal region. In order to make a definitive tissue diagnosis, a supracerebellar infratentorial surgical approach with complete resection was performed. During the resection, brownish fluid was aspirated from the cyst and the cyst wall was removed. The pathological diagnosis was a pineal cyst.
Conclusions: Although cases have been described of pineal apoplexy with an underlying cyst, this case describes the development of a progressive pineal cyst secondary to a hemorrhage. This case demonstrates that pineal hemorrhage may be a promotor for the development or progression of pineal cysts.