CT findings of gastric and intestinal anisakiasis as cause of acute abdominal pain Poster No.: C-2258 Congress: ECR 2015 Type: Educational Exhibit Authors: S. Marcos 1, J. Gonzalez 1, L. Sarria Octavio 1, R. Larrosa 2 ; 1 2 Zaragoza/ES, ZARAGOZA, SP/ES Keywords: DOI: Inflammation, Edema, Education, CT, Small bowel, Gastrointestinal tract, Abdomen 10.1594/ecr2015/C-2258 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 7
Learning objectives The aim of this poster is to describe the CT findings of gastric and intestinal anisakiasis. Background Anisakiasis is a parasitic disease caused by the intake of raw or undercooked fish or cephalopods contaminated by larvae of the Anisakidae family, most common Anisakis simplex, A. pegreffii and Pseudoterranova decipiens. With the consumption of parasitized fish, humans become an accidental host, in which the worms cannot live and die in approximately 2-3 weeks. Depending on where of the digestive system are Anisakis larvae stuck, we classify anisakiasis into three different types: gastric anisakiasis, intestinal anisakiasis and ectopic anisakiasis. Cases of gastric anisakiasis are easier to diagnose, because stomach is accessible by endoscopy, and it allows us to identify the Anisakis larvae on the gastric mucosa. Intestinal anisakiasis is a rare pathology, and it's difficult to diagnose because the small bowell is not accessible by endoscopy. Therefore, the diagnosis of this rare entity is based on the clinical history and the CT findings. Findings and procedure details A retrospective review from September 2006 to October 2014 identified seven patients with acute abdominal pain, to whom CT scan had been done and were diagnosed with gastrointestinal anisakiasis. Six patients were diagnosed with intestinal anisakiasis, and one patient was diagnosed with gastric anisakiasis, all of them gave positive test results for anti-anisakidae antibody. The most remarkable CT finding of the patients with intestinal anisakiasis was severe submucosal edema, showed in 3 of 6 patients. Infiltration of mesenteric fat adjacent to the affected intestine was showed in 3 of 6 patients. Ascites and fluid collection around the involved intestine were found in 4 of 6 patients. There was no evidence of complete obstruction in none of the six patients. Page 2 of 7
Fig. 1: A 65-year-old woman with intestinal anisakiasis. The CT scan shows an edematous segment of the intestinal wall (arrow) and a small amount of ascitic fluid. Page 3 of 7
Fig. 2: A 53-year-old man with intestinal anisakiasis. CT scan shows submucosal edema of jejunal loops. Page 4 of 7
Fig. 3: Submucosal edema of the intestinal wall with infiltration of the mesenteric fat and fluid collection. Page 5 of 7
Fig. 4: The CT scan demonstrates ascites in the pelvis. The CT scan of the patient with gastric anisakiasis showed marked focal submucosal edema, simulating a gastric submucosal mass. However, the patient had acute inflammatory symptoms and the clinical findings were not related to a suspicion of malignant tumour. Later biopsy proved that it was an inflammatory reaction to Anisakis larvae. Fig. 5: A 30-year-old woman with gastric anisakiasis. The CT scan identifies a raised submucosal lesion on the greater curvature of the stomach. Conclusion Page 6 of 7
Although the patients' history of fish intake is not always remembered, gastrointestinal anisakiasis may be suspected in those patients with acute abdominal pain and CT findings of submucosal edema, increased attenuation of adjacent fat and ascites without complete intraluminal occlusion. Personal information References Shibata E, Ueda T, Akaike G, Saida Y. CT findings of gastric and intestinal anisakiasis. Abdom Imaging. 2014 Apr;39(2):257-261 Ogata M, Tamura S, Matsunoya M. Sonographic diagnosis of intestinal anisakiasis presenting as small bowell obstruction. J Clin Ultrasound. 2014 Jun 25. doi: 10.1002/ jcu.22194 Kim WK, Song SY, Cho OK, Koh BH, Kim Y, Jung WK, Kim MY. CT findings of small bowell anisakiasis: analysis of four cases. J Korean Soc Radiol. 2011;64:167-171 Kim SG, Jo YJ, Park YS, Kim SH, Song MH, Lee HH, Kim JS, Ryou JW, Joo JE, Kim DH. Four cases of gastric submucosal mass suspected as anisakiasis. Korean J parasitol. 2006 Mar;44(1):81-86 Pravettoni V, Primavesi L, Piantanida M. Anisakis simplex: current knowledge. Eur Ann Allergy Clin Immunol. 2012 Aug;44(4):150-156 Shrestha S, Kisino A, Watanabe M, Itsukaichi H, Hamasuna K, Ohno G, Tsugu A. Intestinal anisakiasis treated successfully with conservative therapy: importance of clinical diagnosis. World J Gastroenterol. 2014 Jan 14;20(2):598-602 Page 7 of 7