Sunday, March 8, 2020

Answer to Case 583

Answer to Parasite Case of the Week 583: Immature Taenia sp. proglottids.

I apologize that this was more challenging than I meant it to be. I should have mentioned that these objects were passed through the anus (sorry about that omission!)

Note that the objects seen here are made up of repeating chains of proglottids, some which are longer than they are wide, consistent with a Taenia sp. rather than Diphyllobothrium/Dibothriocephalus sp.
As Blaine mentioned, the far left proglottid *might* have a lateral uterine pore which would support a diagnosis of Taenia sp.

In my mind, the histologic sections don't add much to this case. They show the classic features of a cestode (thin outer tegument with a loose underlying stroma containing calcareous corpuscles and longitudinal muscle fibers) with central reproductive structures. However, there is not enough differentiation of these structure present to allow for definitive confirmation of the gross identification.


Old One said...

Hopefully I've learned my lesson. Never bet against Taenia (et tu the masters of the Blog).

Anonymous said...

Old One, don't feel so bad. I did call another case of Sparganosis as Taenia, now I call the reverse. It's time to laugh at oneself.
Florida Fan

ParasiteGal said...

Yes, don't feel bad at all Old One! It was partly my fault for neglecting to mention where the specimen came from.