In this book we have taken a comprehensive look at the subject of familial and hereditary gastric tumors. In particular, the aim of this novel editorial work is to propose the correct management of hereditary diffuse gastric cancer patients, focusing in particular on E-cadherin germline mutations, clinical criteria definition, genetic screening and molecular mechanisms, pathology and microscopic features, surgical treatment and clinical approach for asymptomatic mutation carriers. We also describe other inherited predispositions involving gastric carcinoma.