Answer to Case 455

Answer: Coenurosis, an infection with the larval form of either Taenia serialis or T. multiceps. While the the former has a predilection for soft tissue, the latter commonly involved the eye and central nervous system and is the likely 'culprit' in this case. The multicystic nature and presence of multiple protoscoleces within a cyst is characteristic for coenurosis and allows this infection to be differentiated from cysticercosis which only has one protoscolex per cyst.

Also note that the protoscoleces are larger and more complex than those of Echinococcus species, allowing us to rule out this similar cestode infection.

The CDC DPDx group has some great information and photographs of coenurosis which you can find here:  https://www.cdc.gov/dpdx/coenurosis/index.html

Thank you to everyone who wrote in on this challenging case, and kudos to Blaine for getting it correct!