A case of thalamic hydatid cyst.

Cerebral hydatidosis account for approximately 1-2% of patients with hydatid disease. Fifty percent to 75% of intracranial hydatid cysts are seen in children. The cerebral hydatid cysts are usually single and located in the watershed of the middle cerebral artery. To our knowledge, no case of hydatid cyst in the thalamic location has been reported. A 4-year-old boy presented with the left sided weakness. A right thalamic hydatid cyst without rim enhancement and perifocal oedema was detected on the computed tomographic (CT) scan. He was put on albendazole, but headache, nausea and vomiting developed and hemiparesis got worse in the following two weeks. The non-contrast repeat CT showed the pericystic oedema. The rim enhancement and pericystic oedema were also present on magnetic resonance imaging scans. The right thalamic hydatid cyst was removed via the transcallosal approach. The cyst aspiration and intracystic injection of hypertonic saline were performed before the cyst removal. Leakage of the cyst fluid was conceivably the cause of the development of rim enhancement and pericystic oedema. Patients receiving albendazole for the treatment of cerebral hydatid cysts should be closely followed. The surgery is still the choice of treatment in cerebral hybrid cysts, in our opinion.