Answer to Case 805

Answer to the Parasite Case of the Week 805: Anisakis sp. larva

As noted by Idzi, "For sure the patient has consumed raw/undercooked fish, as this is one of the anisakids! Indeed the Y-shaped lateral chords are typical!" Anisakis species have Y-shaped lateral chords, whereas Pseudoterranova sp. have plumper, 'butterfly' shaped chords.

Here are the characteristic features, including the Y-shaped lateral chords - among the best I've seen:

SM noted that "The location seems to be the intestinal wall or mesentery. The worm penetrated the wall and caused granulomatous inflammation with eosinophils, leading to intussusception."

Thanks again to Dr. Jones for sharing this classic case!