Background: Familial aggregation of gastric cancer has pointed out to a possible hereditary and genetic factor involved in the carcinogenesis of this disease. The diffuse type gastric cancer patients are frequently younger and the tumor has locally infiltrative growth pattern early in its development. Observation of families with frequent early onset gastric cancer has led to the identification of a novel gene implicated in gastric cancer susceptibility: CDH1/E-cadherin. Diffuse familiar gastric cancer is defined as any family presenting: two first-degree relatives with diffuse gastric cancer, one of them with age under 50 years or at least 3 first-degree relatives irrespective age of onset.
Case report: The family reported by us does not fit in any of the classification proposed. The precise identification of these families by clinical and molecular tools is of great importance. The case reported is an example of a family that probably is a form of hereditary gastric cancer not yet fully understood.
Conclusion: Soon there will be new criteria, possibly including genetic and molecular characteristics.