Abdominal Angiostrongyliasis: 24 Cases Diagnosed on Specimens from Surgical Emergencies
M Saravia, V Argueta, R Orozco, L Castillo. Hospital General San Juan de Dios, Guatemala, Guatemala
Background: Angiostrongylus costaricensis is a nematode found in the American continent. Humans are accidental hosts. After the infection, the parasite migrate trough the intestinal wall and reach the mesenteric arteries of the ileocecal region. Most symptoms associated with A. costaricensis are due to an inflammatory/ischemic reaction of the tissues supplied by the affected vessels. Typically, the patient presents with acute abdominal pain. Depending upon the severity of the ischemia within the bowel, the patient can develop necrosis and even perforation. The diagnosis of angiostrongyliasis is made trough the histopathological confirmation of the parasite.
Design: We reviewed 24 histologically confirmed cases of abdominal angiostrongyliasis, from 1999 to 2008. Clinical, macroscopic and microscopic findings that could be useful for the clinician and pathologist to diagnose this disease were searched for.
Results: There were 17 male and 7 female patients; aged 1 to 74 years (mean 23.6). All cases presented to the emergency room as acute abdomen; most frenquently clinical interpreted as acute appendicitis. In 5 cases, a right lower quadrant mass was palpable. The pathological specimens derived from 6 appendectomies, 7 terminal ileum resections, 10 ileo-colic resections and 1 yeyunal resection. One patient needed re-intervention 10 weeks later due to another intestinal perforation. Macroscopically, the external surface of the specimens showed vascular congestion, fibrosis and hemorrhage. Thickening of the intestinal wall, sometimes simulating a mass, was a striking feature. Mucosal findings included 5 cases with flattening of the mucosa, 6 with ulcerations and 4 with a cobblestone pattern. Transmural necrosis or perforation was found in 14 of the 24 cases, including 1 yeyunal perforation. Histologically, abundant presence of eosinophils and vascular necrosis were always distinctive findings. The amount of eggs, larvae and adult worms varied from case to case. Some had abundant adult parasites, larvae and eggs while others needed ample sampling to find occasional eggs.
Conclusions: This is a large series of confirmed abdominal angiostrongyliasis cases reported from Guatemala. It illustrates the presentation of this disease for the clinician as well as for the surgical pathologist. Abdominal angiostrongyliasis frequently presents as an intestinal resection specimens with clinical history of acute abdomen. It is important for American pathologists to recognize it due to the increase immigration to the USA from endemic areas.
Monday, March 9, 2009 11:45 AM
Platform Session: Section G 2, Monday Morning