Next Page

Radiological Diagnosis

It is seldom that the correct diagnosis will be made radiologically, although there are often significant roentgen findings. Only where the disease is endemic is the possibility of anisakiasis likely to be recognized. In the stomach the findings may mimic those of peptic ulceration or neoplasm. The mucosa is edematous, and the stomach wall may be thickened, with rigidity and decreased peristalsis, but actual ulceration is rarely present (Fig.11.3). A submucosal mass with intact but stretched mucosa may occasionally be present, representing an eosinophilic phlegmon, usually in the body or antrum of the stomach (Fig.11.4B). Using double-contrast techniques the worm (larva) has been demonstrated as it burrows into the gastric mucosa (Figs.11.4A, 11.5, 11.6); (it may be seen and recognized, and even removed endoscopically). So far the worm has only been recognized within the alimentary tract in the stomach and, in a few patients, the ileum and ascending colon. It is probably too small and too thin to be seen except on a double-contrast barium study or at endoscopy.

The radiographic findings in 226 patients with acute gastric anisakiasis were reported by Kusuhara et al (1984). Indeterminate findings included coarse and broad gastric folds caused by mucosal edema in 224 patients (98%); in 179 of these patients (88%) the edema was so extensive that it occupied more than half of the entire gastric wall. The most specific finding, present in 139 patients, was the appearance of a threadlike filling defect about 3 cm long, representing the Anisakis worm.


Fig. 11.3 Anisakiasis in a 60 year-old Japanese man complaining of severe epigastric pain. (A) A double-contrast upright view of the stomach shows thickening of the antral wall and narrowing of the lumen. An Anisakis was removed and a follow-up study (B) reveals the stomach to be normal. (Courtesy of Dr. Yoshihiro Hiramatsu, Tokyo, Japan).


Fig. 11.4 (A) Anisakis worm outlined by double-contrast barium meal in the stomach of an adult Japanese patient. (B) A well-defined eosinophilic phlegmon has caused an intramural inflammatory mass in the stomach of another Japanese patient. (Courtesy of Dr. Masayoshi Namiki., Japan; reprinted from W.P. Cockshott and J.H. Middlemiss: Clinical Radiology in the Tropics, 1979, with permission).

Fig. 11.5 Anisakis worms outlined by double-contrast barium studies in two different Japanese patients. (A and B) A 54 year-old woman who had eaten cod fish sashimi six hours earlier. (C) A 33 year-old woman who experienced two days of epigastric distress and vomiting after eating raw mackerel. The worms were removed by fiberoptic endoscopy. (Courtesy of Dr. Kazuo Nagano and Dr. Tatsuya Yamada, Japan; reprinted from W.P. Cockshott and J.H. Middlemiss: Clinical Radiology in the Tropics, 1979, with permission).

Fig. 11.6 Anisakiasis in a 44-year-old Japanese man who had eaten a mackerel the previous night and then developed stomach aches. Double contrast study reveals several live Anisakis worms within the stomach (arrows). (Courtesy of Dr. Yoshihiro Hiramatsu, Tokyo, Japan).

Back to the Table of Contents

Copyright: Palmer and Reeder

Tropical Medicine Mission Index of Diseases About Tropical Medicine Tropical Medicine Home Page Tropical Medicine Staff