Sebaceous tumours: a prototypical class of skin tumour for universal germline genetic testing

Lynch syndrome (LS) is an adult-onset cancer predisposition caused by a germline pathogenic variant affecting one of four mismatch repair (MMR) genes (MLH1, MSH2, MSH6, or PMS2). The vast majority of LS gene carriers are unknown yet may benefit from risk-reducing interventions such as targeted cancer screening and aspirin chemoprevention, the latter being associated with a persistent and long-term reduction in colorectal cancer (CRC) incidence.