Gastric carcinoma (malignant ulcer)
- Epidemiology. Gastric carcinoma is more common in Japan than in the United States, and has a decreasing incidence in the United States.
- Dietary factors can be risk factors, and include smoked fish and meats, pickled vegetables, nitrosamines, benzpyrene, and decreased intake of fruits and vegetables. Other risk factors include H. pylori infection, chronic atrophic gastritis, smoking, blood type A, bacterial overgrowth in the stomach, prior subtotal gastrectomy, and Menetrier disease.
- Clinically, gastric carcinoma is often (90%) asymptomatic until late in the course, when it can produce weight loss and anorexia. It can also present with epigastric abdominal pain mimicking a peptic ulcer, early satiety, and occult bleeding with iron deficiency anemia.
- Pathology. Gastric carcinoma is most commonly located in the lesser curvature of the antrum, and causes a large (>3 cm), irregular ulcer with heaped-up margins and a necrotic ulcer base. It may also occur as a flat or polypoid mass.
- The intestinal histologic type microscopically shows gland-forming adenocarcinoma.
- The diffuse type of gastric carcinoma shows diffuse infiltration of stomach by poorly differentiated tumor cells, frequently numerous signet-ring cells (whose nuclei are displaced to the periphery by intracellular mucin), and linitis plastica (thickened “leather bottle”-like stomach) gross appearance.
- Gastric carcinomas may specifically metastasize to the left supraclavicular lymph node (Virchow sentinel node) and to the ovary (Krukenberg tumor).
- Diagnosis is by endoscopy with biopsy; treatment is with gastrectomy. The prognosis is poor, with overall 5-year survival of 20%.