Recurrent Papillary Bladder Tumors in a Boy With Lynch Syndrome.

Lynch syndrome (LS) is an autosomal dominant genetic disorder defined by germline mutations in one of four mismatch repair genes including PMS2, MLH2, MSH1, MSH2, or deletion in the EPCAM gene.1 The most common urologic manifestation of LS is upper tract urothelial carcinoma, which occurs in up to 20% of patients with LS.2 While data are scarce, there is growing evidence of an increased relative risk of bladder malignancy in patients with LS.3,4 Bladder tumors in children are a rare entity and the link between pediatric bladder tumors and LS has not been previously reported to our knowledge.