Gastroenterology and Hepatology Board Review: Pearls of Wisdom, Third Edition

Section III STOMACH

CHAPTER 15. Gastric Infectious Disorders

Kevin C. Ruff, MD

Image What viral infections are associated with gastric ulcers?

Cytomegalovirus and Herpes simplex type 1.

Image A biopsy from a gastric ulcer reveals granulomas. What is the differential diagnosis?

Infection (tuberculosis, histoplasmosis), Crohn’s disease, sarcoidosis, and foreign body reaction.

Image Menetrier’s disease is associated with what viral infection?

Menetrier’s disease in childhood is usually associated with gastric cytomegalovirus infection.

Image What other gastric infection is associated with the development of Menetrier’s disease?

Helicobacter pylori. (Note: H. pylori is covered further in the chapter on Peptic Ulcer Disease.)

Image An acutely ill patient is found to have purulent gastric inflammation on endoscopy. What is the most likely diagnosis?

Phlegmonous gastritis. Phlegmonous gastritis is a rare bacterial infection of the submucosa and muscularis propria of the stomach. Acute necrotizing gastritis (gangrene of the stomach) is a rare, often fatal disease that is now thought to be a variant of phlegmonous gastritis.

Image What bacterial organism is most commonly associated with phlegmonous gastritis?

Phlegmonous gastritis has been associated with alpha-hemolytic streptococcus in about 50% of the cases. Escherichia coliEnterobacter, other Gram-negative bacilli, and Staphylococcus aureus have also been implicated.

Image True/False: The mortality rate of phlegmonous gastritis approaches 25%.

False. The mortality rate of phlegmonous gastritis is close to 70%, probably because it is so often misdiagnosed and treatment is initiated too late. The definitive treatment is resection or drainage of the stomach combined initially with broad-spectrum antibiotics.

Image True/False: Emphysematous gastritis, a variant of phlegmonous gastritis, results from infection with gas-producing organisms.

True. Predisposing factors are gastroduodenal surgery, ingestion of corrosive materials, gastroenteritis, or gastrointestinal infarction.

Image What part of the gastrointestinal tract is most commonly involved in mucormycosis?

The stomach. The typical lesion is a deep bleeding ulcer with black indurated edges.

Image A 23-year-old woman develops severe abdominal pain after eating sushi. Upper endoscopy reveals a small worm protruding from the mucosa. What is the most likely diagnosis?

Anisakiasis. This is acquired by eating sushi or other types of raw fish.

Image True/False: Histoplasmosis of the gut mainly affects the stomach.

False. The colon and the ileum are the most common sites. The stomach is rarely involved.

Image Biopsies of the gastric antrum in a patient with diffusely congested and ulcerated mucosa show chronic active gastritis with inclusion bodies. What is the most likely diagnosis?

Cytomegalovirus gastritis. The typical appearance of cytomegalovirus on histology shows intranuclear inclusion bodies often referred to as an “owl eye” appearance.

Image Multiple small ulcerated plaques on endoscopic inspection of the stomach give a “cobblestone” appearance in which viral infections?

Hsimplex and Varicella zoster.

Image A barium study of the upper GI tract shows evidence of a stricture in the mid gastric body with an “hourglass” shape on x-ray. Which bacteria is the most likely cause?

Syphilis. Thickened gastric folds, mucosal nodularity, and irregular/serpiginous ulcers can also be present on endoscopic examination.

Image True/False: Gastric infection with Mycobacterium tuberculosis is a rare entity that usually occurs in association with pulmonary tuberculosis.

True.

Image Mycobacterium avium complex (MAC), a common opportunistic bacterial infection among patients with AIDS, commonly affects the stomach.

False.

Image What risk factors contribute to the development of mucormycosis?

Malnutrition, immunosuppression, antibiotic use, and acidosis (especially diabetic ketoacidosis).

Image True/False: Gastric outlet obstruction can be a symptom of cryptosporidiosis.

True. Strictures in the gastric antrum may cause substantial narrowing and limit gastric emptying.

Image True/False: Ascariasis may cause gastric outlet obstruction.

True. A high burden of Ascaris lumbricoides can lead to intermittent obstruction of the pylorus.

• • • SUGGESTED READINGS • • •

Lee EL, Feldman M. Gastritis and Gastropathies. In: Feldman M, Friedman L, and Brandt L, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Diseases. 9th ed. Philadelphia: Saunders-Elsevier; 2010:845-859.

Kim GY, Ward J, Henessey B, et al. Phlegmonous gastritis: case report and review. Gastrointest Endosc. 2005 Jan;61(1):168-174.