Lesion Size Marks a Histologic and Morphologic Transition in Colorectal Polyps: A 16-Year Cohort of 1,026 Endoscopically Resected Lesions

Abstract Background A clinically useful colorectal polyp study should identify findings that change risk assessment and management, not merely describe lesion counts. We tested whether increasing lesion size marks a coordinated transition in histology and gross morphology and examined the implications for complete-colon evaluation, endoscopic treatment complexity, and surveillance. Methods This retrospective single-center cohort comprised 393 patients undergoing 421 polypectomy procedures during 2010–2025, with 1,026 treated colorectal lesions. Source cross-tabulations were reconstructed for seven size strata, four histologic categories, and five gross morphology categories. Global associations were assessed with Pearson χ² tests and Cramér's V. Villous-containing histology (tubulovillous or villous adenoma) was compared between lesions > 2.0 cm and ≤ 2.0 cm using an odds ratio (OR) with 95% confidence interval (CI). Results Histologic composition changed strongly across size strata (χ²=1069.9, df = 18, P < 0.001; Cramér's V = 0.590). Villous-containing histology increased from 1.6% in 0.3–0.5-cm lesions to 85.7% in lesions > 5.1 cm. Lesions > 2.0 cm had villous-containing histology in 119/174 (68.4%) versus 197/852 (23.1%) lesions ≤ 2.0 cm (OR 7.19, 95% CI 5.03–10.28; P < 0.001). Gross morphology also shifted with size (χ²=161.8, df = 4, P < 0.001; Cramér's V = 0.40): spreading morphology increased from 3/852 (0.4%) among lesions ≤ 2.0 cm to 28/174 (16.1%) among lesions > 2.0 cm, while broad-based morphology decreased from 56.8% to 31.6%. Of 174 large lesions, 138 (79.3%) required fragmentation resection and seven required a planned second stage. Bleeding occurred in 11/421 procedures (2.6%), all controlled endoscopically, and no perforations were recorded. Among 74 patients with a distal lesion previously detected by sigmoidoscopy, full colonoscopy identified additional proximal polyps in 39 (52.7%) and malignant tumors in six (8.2%). Conclusion Increasing lesion size marked a clinically important phenotypic transition rather than a simple increase in diameter: larger lesions were substantially more likely to contain villous architecture, had a different macroscopic configuration, and more often required complex resection. The high yield of proximal pathology after distal lesion detection further supports complete-colon examination. These findings identify lesion size as an integrative marker for histologic risk, technical complexity, and surveillance planning.