Hereditary lobular breast cancer is an inherited syndrome that is associated with the CDH1 germline mutations. The CDH1 gene plays a crucial role in the correct function of human cells. Loss of the encoded protein, so called E-cadherin, represents a dramatic event; in human epithelial cancers, as diffuse gastric and lobular breast tumors, this loss is responsible of cancer metastatization, through lymphatic and vessel system.

CDH1 germline mutations is a rare event that affects some family members with lobular breast cancer, also in absence of diffuse gastric cancer. In this article-review, we described this new syndrome, called hereditary lobular breast cancer, proposing novel clinical criteria to admit individuals at CDH1 genetic screening: a) bilateral LBC with or without family history for LBC, with age at onset <50 years; and b) unilateral LBC with family history for LBC, with age at onset <45 years. All mutant carriers, or high risk individuals, should be discussed in a multidisciplinary team to purpose prophylactic mastectomy or breast surveillance. (By Dr Giovanni Corso, https://jmg.bmj.com/content/55/7/431 )