Chronic gastric anisakiasis presenting as pneumoperitoneum

Area of Science:

• Gastroenterology
• Parasitology
• Surgical Pathology

Background:

• Gastric anisakiasis diagnosis typically relies on endoscopic identification of Anisakis larvae.
• Uncommon presentations of parasitic infections can pose diagnostic challenges.

Observation:

• A 70-year-old woman presented with abdominal pain and fullness, showing free air on chest X-ray, leading to a diagnosis of perforation peritonitis.
• Emergency laparotomy revealed a gastric mass, and subsequent partial gastrectomy was performed.

Findings:

• Histological examination of the gastric mass identified a foreign body consistent with Anisakis larvae within a granuloma.
• Evidence of peritonitis and a positive anti-Anisakis larvae immunoglobulin G antibody test supported the diagnosis.
• Chronic gastric anisakiasis was suspected due to eosinophilic granuloma and larval remnants.

Implications:

• This case demonstrates that gastric anisakiasis can present as acute gastric perforation, a rare but critical manifestation.
• The findings underscore the need for broader differential diagnoses in acute abdominal conditions, including parasitic infections.
• Early recognition and appropriate management are crucial for favorable outcomes in complex parasitic infections of the gastrointestinal tract.