Giant glioependymal cyst in an infant.

The authors report the case of an infant with a giant glioependymal cyst. Although it has been suggested that these cysts originate from the tela choroidea, their origin remains controversial. This 35-month-old girl with truncal ataxia was referred to the authors' hospital. Magnetic resonance imaging revealed a giant cystic mass extending from the anterior to the posterior cranial fossa. Hydrocephalus was caused by obstruction of the sylvian aqueduct. Endoscopic fenestration of the cyst wall was performed. Histochemical and immunohistochemical staining identified the lesion as a glioependymal cyst. Magnetic resonance imaging performed 8 months later suggested that the cyst originated from the tela choroidea. At 5-year follow-up, there was no tumor recurrence and she had fully recovered. The origin of glioependymal cysts is discussed, and the authors suggest that their origin is the tela choroidea.