Adult celiac disease and its malignant complications.

Adult celiac disease is a chronic intestinal disorder that has been estimated to affect up to 1-2% of the population in some nations. Awareness of the disease has increased, but still it remains markedly underdiagnosed. Celiac disease is a pathologically defined condition with several characteristic clinical scenarios that should lead the clinician to suspect its presence. Critical to diagnosis is a documented responsiveness to a gluten-free diet. After diagnosis and treatment, symptoms and biopsy-proven changes may recur and appear refractory to a gluten-free diet. Recurrent symptoms are most often due to poor diet compliance, a ubiquitous and unrecognized gluten source, an initially incorrect diagnosis, or an associated disease or complication of celiac disease. Some patients with persistent symptoms and biopsy-proven changes may not have celiac disease at all, instead suffering from a sprue-like intestinal disease, so-called unclassified sprue, which is a specific entity that does not appear to respond to a gluten-free diet. Some of these patients eventually prove to have an underlying malignant cause, particularly lymphoma. The risk of developing lymphoma and other malignancies is increased in celiac disease, especially if initially diagnosed in the elderly, or late in the clinical course of the disease. However, recent studies suggest that the risk of gastric and colon cancer is low. This has led to the hypothesis that untreated celiac disease may be protective, possibly due to impaired absorption and more rapid excretion of fat or fat-soluble agents, including hydrocarbons and other putative cocarcinogens, which are implicated in the pathogenesis of colorectal cancer.