2026 年 13 巻 p. 77-84
Choroid plexus cysts are typically benign lesions found within the ventricular system during prenatal imaging and are usually asymptomatic. Intraparenchymal choroid plexus cysts, especially in adults, are exceptionally rare, with very few reported cases. This case report aims to present a rare instance of a symptomatic, intraparenchymal choroid plexus cyst in an adult patient and to discuss the diagnostic and surgical considerations involved. We present the case of a 50-year-old man with complaints of lower extremity weakness and imbalance who was found to have a bilobulated cyst in the frontal cortex causing significant mass effect and midline shift. The patient underwent cyst fenestration through endoscope-assisted open craniotomy, with marked postoperative reduction in cyst size and resolution of neurological symptoms. Histopathology confirmed the diagnosis of a choroid plexus cyst. This case highlights the importance of considering rare pathologies such as choroid plexus cysts in the differential diagnosis of cystic brain lesions with mass effect in adults.
