title: Endoscopic overestimation of colorectal polyp size.
abstract: OBJECTIVE
  Polyp size ≥ 1 cm triggers more frequent colonoscopic surveillance, yet size is typically based on subjective endoscopic estimates. We sought to compare contemporary assessments of polyp size by endoscopic estimation and pathology measurement.
  
  
  METHODS
  Colonoscopy and pathology reports were reviewed from the 2012 medical records at a large institution. Only polyps resected in toto with both endoscopic estimates and pathology measurements were included. Pathology measurements were considered the criterion standard. Factors affecting endoscopic miscall rates were assessed by multivariate analyses.
  
  
  RESULTS
  From 6067 polyps resected, both endoscopic and pathology sizes were available on 1528. Distribution of polyp size appraised by endoscopy but not by pathology revealed modal clustering, particularly around 1 cm. Among 99 polyps endoscopically called 1 cm, 72% were <1 cm on pathology. Of all 222 polyps estimated as ≥ 1 cm on endoscopy, 46% were <1 cm on pathology; of 1306 polyps estimated as <1 cm, 3.9% were ≥ 1 cm on pathology. By histology, 39% of adenomatous, 59% of sessile serrated, and 73% of hyperplastic polyps were overcalled; P = .008. By configuration, 34% of pedunculated, 49% of sessile, and 61% of flat polyps were overcalled; P = .014. Endoscopic overestimation was more common in women (54%) than in men (40%) (P = .03) and with proximal (56%) than distal (40%) sites; P = .02. Miscall rates were unaffected by endoscopist covariates.
  
  
  CONCLUSIONS
  Substantial discordance exists between endoscopic and pathology-based assessments of polyp size. Almost half of polyps called advanced on endoscopic estimates of size ≥ 1 cm fell below this threshold on actual pathology measurements.
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Bradley W
authors: BW
authors: Anderson
authors: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Thomas C
authors: TC
authors: Smyrk
authors: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA.
authors: Kari S
authors: KS
authors: Anderson
authors: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA.
authors: Douglas W
authors: DW
authors: Mahoney
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Mary E
authors: ME
authors: Devens
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Seth R
authors: SR
authors: Sweetser
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: John B
authors: JB
authors: Kisiel
authors: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
authors: David A
authors: DA
authors: Ahlquist
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000368:Aged; D015331:Cohort Studies; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012002:Rectal Diseases / Q000473:pathology; D012189:Retrospective Studies; D012737:Sex Factors; D047368:Tumor Burden