A Rare Posterior Fossa Intraparenchymal Cerebellar Hydatid Cyst Mimicking a Cystic Brain Tumor in a Child

ABSTRACT: Background: Intracranial hydatid disease is an uncommon manifestation of Echinococcus granulosus infection, accounting for only 1–2% of all hydatid cases. Most intracranial lesions occur supratentorially, whereas intraparenchymal cerebellar hydatid cysts are exceptionally rare, particularly in children. Their radiological appearance may closely resemble other cystic posterior fossa lesions, making preoperative diagnosis difficult. Case Description: A 9 year old boy from Balkh Province presented with a three year history of headache, gait instability, and lower limb weakness. MRI revealed a large cystic lesion in the left cerebellar hemisphere, initially suspected as pilocytic astrocytoma or arachnoid cyst. Suboccipital craniectomy exposed a laminated hydatid cyst wall, confirming the diagnosis intraoperatively. Because intact removal was not feasible in the confined posterior fossa, controlled decompression and complete excision were performed. The patient improved neurologically and was discharged on day five with albendazole therapy. Conclusion: Posterior fossa cerebellar hydatid cysts are extremely rare in children and often mimic cystic brain tumors. This case underscores the need to consider hydatid disease in endemic regions and highlights the value of intraoperative recognition. Thepite the surgical challenges of the posterior fossa, controlled decompression and complete excision combined with albendazole therapy can yield favorable outcomes. Keywords: Cerebellar hydatid cyst; Posterior fossa; Intracranial echinococcosis; Pediatric neurosurgery; Brain hydatid disease; Case report.