Benign Neoplasms in Biallelic Nth-Like DNA Glycosylase 1-Associated Tumor Syndrome: Expanding the Clinical Phenotype

Nth-like DNA glycosylase 1-associated tumor syndrome (NATS) is a rare autosomal recessive cancer predisposition syndrome linked to colorectal, endometrial and ovarian cancers. Given its recent description in 2015, the full spectrum of benign manifestations remains uncertain. We describe a 53-year-old man with a biallelic pathogenic Nth-Like DNA Glycosylase 1 variant, c.244C>T(p.Gln82*), duodenal and colonic adenomas, and an unusual aggregation of benign neoplasms, including multiple oral, hepatic, splenic, and vertebral hemangiomas, an esophageal lipoma, schwannomas, and meningiomas. This represents the first report of schwannomas and oral or vertebral hemangiomas in biallelic NATS, expanding the phenotypic spectrum and supporting consideration of NATS in patients with colorectal polyposis and clustered benign neurovascular tumors.