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

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.