CDH1 and breast lobular carcinoma: Additional clinical indications for genetic testing for CDH1 mutations include: HDGC in two relatives with histologic confirmation of tumor in only one individual, diffuse gastric carcinoma in an individual < 40 years regardless of family history, or individuals and families with both signet ring cell gastric carcinoma (including one case before 50 years of age) and lobular breast carcinoma [2].