What is the difference between intestinal and diffuse stomach cancer?
Intestinal and diffuse are two ways of describing adenocarcinoma of the stomach, based on how the cancer cells look under a microscope. Adenocarcinoma is cancer that starts in gland cells. It accounts for most stomach cancers.
Intestinal adenocarcinomas are well differentiated. That means the cells still look much like normal cells. They also line themselves up into tubes or gland-like shapes. Pathologists name these tumors tubular, papillary, or mucinous, depending on the pattern.
Diffuse adenocarcinomas are poorly differentiated or undifferentiated. The cells look little like normal cells and form no glands at all. Instead of building one lump, they scatter and creep through the wall of the stomach. When that spread is wide, the stomach wall thickens and stiffens into a rigid sac. Doctors call that linitis plastica.
Diffuse tumors tend to grow and spread faster than intestinal ones. They can also be harder to treat.
Both patterns come from a system called the Lauren classification. Some tumors show mixed features of both, and your report may say so.
Why the pattern matters in practice
The difference is not just a label. It changes how the cancer is found.
An intestinal tumor usually grows as a mass. An endoscopy camera can see it, and a biopsy can sample it. A diffuse tumor may leave the stomach lining looking nearly normal while the cancer spreads underneath. That is one reason diffuse cancers are sometimes found late. It is also why a doctor may repeat an endoscopy with deeper biopsies when symptoms persist after a normal-looking exam.
The two types keep different company as well. Intestinal-type cancer is tied to long-term swelling of the stomach lining. Chronic infection with the bacterium Helicobacter pylori is a major risk factor. It raises risk most in the lower and middle stomach. Smoking adds to the risk, as does a diet low in fruits and vegetables or high in salted, smoked, or poorly preserved foods.
The inherited form of diffuse cancer
Diffuse stomach cancer has an inherited version that intestinal cancer does not. It is caused by harmful changes in the CDH1 gene. Doctors call it hereditary diffuse gastric cancer.
The numbers are serious. By age 80, the risk of stomach cancer runs about 37% to 70% in men who carry a harmful CDH1 variant. In women it runs 25% to 83%. Women also face a 39% to 55% risk of lobular breast cancer, most often in their late 40s.
Most of these cancers are signet ring cell carcinoma. The name describes the look: a drop of mucus pushes each cell's nucleus to one edge. In a review of 224 stomachs removed as a precaution from CDH1 carriers, cancer was found in 85.4% of the specimens, and at least one focus of signet ring cell carcinoma in 72.6%. Many of those people felt fine.
For carriers, removing the whole stomach is the treatment of choice. It is generally not done before age 18 to 20. People who decline surgery are offered a yearly endoscopy instead. That starts at age 40, or 10 years before the youngest cancer in the family, and not before age 18.
What to do with your report
Find the line in your pathology report that names the type. Does it say diffuse or signet ring cell? Then ask to be referred for genetic counseling and CDH1 testing. That matters most if you were diagnosed young, or if relatives have had stomach cancer or lobular breast cancer. The result can matter for your blood relatives as much as for you.
Sources
Want the full picture? Read our complete explanation: What Is Stomach Cancer? Where It Starts
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