Gastric adenocarcinoma makes up nearly 95% of gastric tumors and accounts for 3% of deaths from cancer.
This tumor is initially asymptomatic. Advanced cases present with abdominal discomfort or pain, anorexia, nausea, vomiting, anemia due to loss of blood, dysphagia, weight loss and changes in the bowel habits.
Grossly, the tumor may have the following features: 1. Exophytic, 2. Flat, 3. Ulcerated, depressed or excavated and 4. Diffuse involvment of the gastric wall (linitis plastica).
Microscopically, the tumor presents as adenocarcinoma with various degrees of differentiation. The exophytic lesion normally appears as a mucin producing adenocarcinoma and is associated with intestinal metaplasia and is more common in males than females (ratio 2:1). The diffuse linitis plastica type presents as signet ring and poorly differentiated tumor and appears in both sexes at an equal frequency. The tumor may mestastsize to the local lymph nodes, and may spread intraperitoneally or hematogenously. The term, Krukenberg tumors is applied to the gastric carcinomas metastatic to the ovaries.