Small intestine & ampulla
Infectious disorders
Anisakis
Author: Hanni Gulwani, M.B.B.S.
Last author update: 1 August 2012
Last staff update: 19 November 2020
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: Anisakis small bowel
Table of Contents
Definition / general | Diagrams / tables | Case reports | Clinical images | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Additional referencesCite this page: Gulwani H. Anisakis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/smallbowelanisakiosis.html. Accessed June 10th, 2023.
Definition / general
- Larvae of ascarids (Anisakidae) are found in sea animals
- After ingesting contaminated raw fish or other sea food, larvae attach to mucosa of stomach or small intestine and cause ulceration, penetration or perforation
Diagrams / tables
Images hosted on other servers:
Life cycle
Case reports
- 37 year old woman with epigastric pain two hours after ingesting fried hake and fish ova and 200 larvae obtained by endoscopy (J Investig Allergol Clin Immunol 2010;20:437)
- 50 year old man with abdominal pain and peripheral eosinophilia after eating raw salmon from Pacific Ocean (Am J Surg Pathol 2003;27:1167)
- Worm found in fresh salmon (Pritt: Creepy Dreadful Wonderful Parasites Blog - Case of the Week 557 [Accessed 13 September 2019])
Clinical images
Images hosted on other servers:
Larvae in terminal ileum
Larvae in fish
Larvae in a herring
Gross images
Contributed by Bobbi Pritt, M.D.
Most likely a
type I Anisakis or
Pseudoterranova
Microscopic (histologic) description
- Serositis, mucosal edema, submucosal abscess with eosinophils surrounding parasite with unpaired excretory gland (renette cell), Y shaped lateral epidermal cords, no apparent reproductive system and a ventriculus (glandular esophagus)
- No lateral alae, no ventricular appendage, no intestinal cecum
Microscopic (histologic) images
Contributed by Bobbi Pritt, M.D.
Most likely a type I Anisakis or Pseudoterranova: anterior boring tooth (left); mucron (terminal spicule-like structure) (right)
Images hosted on other servers:
Larva in submucosa with eosinophils and lymphocytes
Larva in jejunum; note its intestinal lumen (L), the large lateral chords (LC) with a butterfly-like shape and many somatic muscle cells (MC); also a marked eosinophilic infiltrate with neutrophils and lymphocytes
