Cerebral coenurosis mimicking hydatid disease - report of two cases from South India.

Coenurosis, a rare zoonotic disease caused by the larval form of Taenia multiceps (bladderworm) is common in sheep rearing countries, but human infections are rare. Central nervous system involvement produces large giant sized cysts that radiologically closely mimic hydatid cysts. Most human infections resulting in cerebral coenuri have been reported from Europe and Africa. We report two cases of cerebral coenurosis from India, the first in a 55-year-old male presenting with a large cystic lesion in the right parietooccipital region and the second occurring in a 36-year-old male involving the left temporal trigonal region, that radiologically closely mimicked hydatid cyst. Histopathologic examination revealed characteristic features of coenuri with multiple protoscolices invaginating into a large cyst lined by outer cuticular layer. Awareness of this rare parasitic infestation is important to discriminate from the more common hydatid and giant cysticercal cysts.