Pediatric Malignancy in the Setting of Lynch Syndrome: A Case Series and Review of the Literature

Lynch Syndrome (LS) is a hereditary cancer predisposition syndrome caused by germline pathogenic/likely pathogenic variants in mismatch repair (MMR) genes. While LS is not traditionally thought to increase childhood cancer risk, some studies have shown an increased prevalence of germline MMR variants in the pediatric oncology population. Herein, we discuss 55 individuals with pediatric cancer and LS. Of these, MSH2 was the most common germline change (36%). Of those tested for loss of heterozygosity (LOH) or microsatellite instability (MSI), the majority had LOH present (78%) and were MSI high (71%), suggesting the contribution of LS to oncogenesis in these individuals.