Accurate Determination of Colorectal Polyp Counts Is Not Mission Impossible for Pathologists and Is Essential for Surveillance Interval Decision-Making: A Review of 1294 Specimens

Abstract

Abstract Introduction/Objective The US Multi-Society Task Force on colorectal cancer updated recommendations in 2020 for follow-up after colonoscopy. This emphasized differential surveillance intervals based on the number of polyps removed. We determined how often we accurately counted the number of polyps and what submission practices allowed accurate quantification. Methods/Case Report We reviewed consecutive colorectal polyp cases from 10/1 to 12/31, 2019, excluding inflammatory polyps in inflammatory bowel disease. Pathology reports were reviewed to determine if the polyp number could be determined from history, gross description, and histologic findings. When numbers did not match or were unclear, endoscopy reports and glass slides were reviewed. Results (if a Case Study enter NA) 601 cases with 1294 specimens were identified. We accurately determined polyp number in 1235 (95.4%) specimens. 1072 (82.8%) specimens were submitted as single polyp per container (SP), while 222 (17.2%) were submitted with > 1 polyp per container (MP). Polyp number was not quantifiable in 58 (26.1%) MP due to 11 labeled as “multiple polyps” in requisition/endoscopy reports and 47 submitted with polyp number different from number of tissue portions seen grossly and microscopically. In 1 (0.1%) SP, polyp number was unclear because separate portions of tissue contained two different diagnoses. Rate of accurate polyp count is significantly different between SP and MP (p<0.01) by Fisher exact test. Conclusion We accurately determined number of polyps in most specimens (95.4%) because our gastroenterologists usually submit SP. In MP, polyp count in 26.1% of specimens was unquantifiable. This could lead to uncertainty in surveillance follow-up intervals. Therefore, we recommend submitting one polyp per container.