Isolated third ventricular hydatid cyst at the foramina of Monro presenting with obstructive hydrocephalus: A case...

Hydatid cysts are uncommon parasitic lesions of the central nervous system (CNS). Among these, intraventricular involvement is exceptionally rare, with only a handful of cases reported in the literature. Occurrence within the third ventricle is particularly unusual.

We present the case of a 51-year-old male from an endemic region in Iraq who developed a third ventricular hydatid cyst presenting with hydrocephalus. The patient exhibited symptoms of obstructive hydrocephalus, including headaches, vomiting, and gait instability. Magnetic resonance imaging revealed a sharply marginated, cerebrospinal fluid-isointense, non-enhancing cystic lesion measuring approximately 2.8 × 2.5 × 2.3 cm within the third ventricle, obstructing the foramina of Monro, and resulting in triventricular hydrocephalus. Serological testing confirmed Echinococcus granulosus infection. The cyst was surgically removed intact through a transcortical-transventricular approach using the Dowling technique, avoiding rupture-related complications. Postoperative recovery was smooth, and adjunct albendazole therapy was administered.

This case highlights the importance of high clinical suspicion, precise imaging interpretation, and meticulous surgical technique when managing rare CNS hydatid cysts, especially in endemic areas. To the best of our knowledge, this represents one of the very few reported cases of a third ventricular hydatid cyst worldwide. The report highlights both the extreme rarity of this localization and the importance of meticulous surgical removal and adjunct antiparasitic therapy in preventing recurrence, offering valuable insights for neurosurgeons practicing in endemic regions.