Upper Gastrointestinal Neoplasia and Worrisome Thyroid Nodules are Common in Colonic Polyposis of Unknown Etiology (CPUE)

Abstract

Background: Colonic polyposis of unknown etiology (CPUE) is defined as ≥10 cumulative colonic adenomas without a detectable germline pathogenic variant. Surveillance for patients with >100 adenomas is recommended, similar to patients with familial adenomatous polyposis. The utility of extra-colonic screening in patients with 10 to <100 adenomas is not well established. Methods: All CPUE patients seen at our center between 2003 and 2022 were included. Patients were categorized based on the range of cumulative colorectal adenoma count: 10 to 19, 20 to 99, and ≥100. Results: In all, 150 patients were identified of which 20(13.3%) had 10 to 19 cumulative adenomas, 79(52.7%) had 20 to 99 adenomas, and 51(34.0%) had ≥100 adenomas. Compared with patients with 10 to 19 and 20 to 99, patients with ≥100 adenomas were younger (mean 51 vs. 52 vs. 42 y, respectively). Of patients who underwent esophagogastroduodenoscopy, duodenal adenomas were found in 33.3%, 10.1%, and 38% in the 3 groups, respectively, P=0.002. Ampullary adenomas were significantly more common in the ≥100 adenoma group (14.8%, P=0.019) compared with 8.3% and 2.9% in the 10 to 19 and 20 to 99 groups, respectively. Thyroid nodules ≥1 cm were not detected in patients with 10 to 19 adenomas but were found in 23.3% and 14.3% of patients with 20 to 99 and ≥100 adenomas, respectively (P=0.254). Conclusion: In our cohort, duodenal and gastric adenomas occurred in CPUE patients with adenoma count 10 to ≥100 at a relatively high proportion. We recommend a baseline esophagogastroduodenoscopy in all patients with CPUE. While clinically significant thyroid nodules were not detected in patients with 10 to 19 adenomas, they occurred in about one-fifth of the patients with ≥20 adenomas, indicating that thyroid ultrasound is prudent.