Radiographic Findings of Gastrointestinal Anisakiasis: Clinical and Pathologic Correlation

ABSTRACT

PURPOSE: To evaluate the radiographic findings of gastrointestinal anisakiasis with clinical and pathologic correlation. MATERIALS AND METHODS: In ten patients, findings were retrospectively analysed. There were two cases of the gastric variety of gastrointestinal anisakiasis and eight of the intestinal, and they were diagnosed during gastroscopy, by resection during surgery, and on the basis of typical clinical findings. All ten patients underwent both plain radiography and CT scanning of the abdomen. US was performed in five patients and an upper gastrointestinal series in one. Clinical data were evaluated with regard to a history of raw fish ingestion, time from ingestion of raw fish to onset of symptoms, location of abdominal pain, and laboratory data. Radiologic findings were analysed in terms of wall thickening and appearance, mesenteric infiltration, bowel dilatation proximal to lesion, and ascites. RESULTS: All patients had a history of recent ingestion of raw fish and complained of severe abdominal pain that occurred approximately 7-48 hours later. Pain occurred in the lower abdomen in five patients, the epigastrium in four, and the right lower abdomen in two. Laboratory test disclosed the leukocytosis in eight patients and eosinophilia in three. In all cases of intestinal anisakiasis, ileus was demonstrated on plain radiographs of the abdomen, while the upper gastrointestinal series showed mucosal thickening and multiple filling defects. US findings were bowel thickening and dilation, and on CT images, wall thickening revealed a target sign. Mesenteric infiltration and ascites were seen in seven patients. In four who underwent surgery, a cross-section through the lesion revealed submucosal eosinophilic granuloma with Anisakis larva. CONCLUSION: Although the CT findings are non-specific, taken in conjunction with characteristic clinical findings, they may be helpful in the diagnosis of gastrointestinal anisakiasis.