Answer to Case 391

Answer: Coenurosis due to a canine tapeworm, Taenia multiceps, or Taenia serialis. Dogs and other canids are the definitive host, while humans are accidental intermediate hosts. These cestodes are seen worldwide, but most cases have been reported from Africa (where the patient in this case was from).

The diagnosis can be made by identifying multiple everted scolices (protoscoleces) within a large cystic structure. This differs from cysticercosis in which there is only a single protoscolex in each cyst. Note the presence of calcareous corpuscles throughout the stroma which is seen with all cestodes.

The CDC DPDx website has great macroscopic pictures of coenurosis which you can see HERE.