A case report of non-syndromic colonic ganglioneuroma in a patient with juvenile polyposis.

Colonic ganglioneuromas in children are rare, particularly without associated hereditary syndromes like multiple endocrine neoplasia (MEN2B), neurofibromatosis type 1(NF1), or Phosphatase and tensin homolog hamartoma tumor syndrome (PHTS). We report a 12-year-old male with a history of juvenile polyposis syndrome (JPS) and segmental colonic resection for high distal disease burden. During surveillance colonoscopy, a solitary ascending colon polyp was retrieved and found to be a ganglioneuroma. Genetic testing showed gl-9 family hypoxia inducible factor 1 and succinate dehydrogenase complex flavoprotein subunit A variants in the patient and MutL homolog 3 and MutS homolog 3 variants in both the patient and his mother. All genes discovered were classified as variants of uncertain significance. There was no genetic or clinical evidence of MEN2B, NF1, or PHTS. This case highlights that JPS is a heterogenous disorder and may involve increased risk of developing unique polyp subtypes which are not typically associated with that condition. Current JPS recommendations suggest that surveillance colonoscopy may be performed every 3 years which may be insufficient in situations involving novel mutations or unknown JPS genetics.