Teaching Video NeuroImage: Intracranial Multivesicular Hydatid Cyst

A 5-year-old girl with autism-spectrum disorder presented with persistent fever, recurrent episodes of projectile vomiting, increased irritability, and reduced oral intake for 2 months. Neuroimaging showed a left parieto-occipital cystic lesion with multiple septations, perilesional edema, and contrast enhancement of the cyst wall (Figure). Differential diagnoses included a cerebral abscess, cystic tumor, and hydatid cyst. Craniotomy was performed, and the cyst was excised (Video 1), with histopathologic examination confirming a hydatid cyst, a zoonosis caused by infection with the larval stage of Echinococcus granulosis. No additional cysts were found in the chest, abdomen, or spine. Intracranial presentation is rare, seen in up to 1%-2%.1 The usual MRI pattern of an intracranial primary hydatid cyst is that of a single clear cyst with a hypointense rim without contrast enhancement or perilesional edema.1 Superimposed infection or rupture can have a multivesicular presentation with contrast enhancement and perilesional edema.1 Treatment is complete excision. Albendazole perioperatively and postoperatively in cases of a ruptured cyst may help reduce recurrence.2