Hydatid disease of central nervous system, a clinicopathological study of 33 cases.

Objectives: Involvement of central nervous system (CNS) by Hydatid cyst is rare comprising 0.5-4% of all hydatid cysts and principally affecting those younger than 20 years, giving rise to cystic masses mostly in the cerebral hemispheres. To report the clinicopathological findings of CNS hydatid cysts, we diagnosed and review the findings of the previous studies. Materials and Methods: All cases reported in our Section between January 1, 2001, and June 30, 2022, were included in the study. By searching our files, cases were retrieved, and diagnosis was confirmed. Follow-up was received on telephone. Ethical exemption was obtained. Results: Thirty-three cases were diagnosed. Almost all were received from rural areas. There were 17 females and 16 males. Mean and median age were 20 and 19 years, respectively. Over 60% were younger than 20 years of age. All 33 involved the cerebral and cerebellar hemispheres. Seventy six percent were supratentorial while 24% were infratentorial. The most common signs and symptoms included weakness, headaches, and seizures. All appeared as solitary cystic masses on imaging. Almost 67% were clinically suspected to be hydatid cysts. Grossly, thin-walled transparent unilocular or multilocular cysts filled with viscous material were received intact in 52% and in multiple pieces in 48% cases. Intact cysts measured 7 cm on average. All demonstrated typical histology. Of the nine patients whose follow-up was available, one died from unspecified acute surgery related complications. Four patients were asymptomatic at the time of follow-up, whereas four developed recurrent cysts. All eight received albendazole therapy. Conclusion: Cerebellum/posterior fossa location was common. Several cases were received in multiple pieces with increased risk of recurrence. Clinicopathological features were similar to those reported in literature. This series will hopefully serve to increase awareness regarding CNS hydatid disease.