Interobserver variability in the pathological assessment of malignant colorectal polyps

Department of Surgery, University of California, San Francisco, San Francisco, California, United States
British Journal of Surgery (Impact Factor: 5.21). 11/2004; 91(11):1479-84. DOI: 10.1002/bjs.4588
Source: PubMed

ABSTRACT Treatment of patients with malignant large bowel polyps is highly dependent on pathological evaluation. The aim of this study was to evaluate interobserver variability in the pathological assessment of endoscopically removed polyps.
The records of 88 patients with colorectal cancer who underwent endoscopic removal of malignant polyps were reviewed. Study investigators reviewed the initial pathology report; three experienced gastrointestinal pathologists reviewed all slides in a blinded fashion. Interobserver variability of pathological assessment of malignant polyps was analysed by kappa statistics.
Seventy-six (86 per cent) of the 88 patients had malignant polyps and 12 (14 per cent) had carcinoma in situ. Agreement between experienced pathologists was substantial with regard to T stage (kappa = 0.725), resection margin status (kappa = 0.668) and Haggitt's classification (kappa = 0.682), but comparison of initial and experienced pathologists' assessment demonstrated only moderate agreement in these areas (kappa = 0.516, kappa = 0.555 and kappa = 0.578 respectively). Agreement between even experienced pathologists was poor with respect to histological grade of differentiated adenocarcinomas (kappa = 0.163) and angiolymphatic vessel invasion (kappa = - 0.017).
Pathological assessment of malignant polyps varies between observers. Specialist pathologists appear to have a higher degree of consensus among themselves than with generalist pathologists with respect to T stage. The high interobserver variability with regard to histological grade of differentiated tumours is clinically irrelevant. However, variability in the assessment of angiolymphatic vessel invasion limits the value of this measurement for clinical decision making.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Objectives. The purposes of the study are to describe the incidence trend of malignant polyp of large bowel over a 25-year period in the District of Modena and to assess the effect of an organized colorectal cancer screening program. Material and methods. Through the data of a specialized colorectal cancer Registry, we evaluate the clinical and pathological features of the polyps. Trend analysis was assessed with the Joinpoint Regression Program. Results. A total of 172 patients with malignant polyps were diagnosed throughout the study (3.5% of 4.835 registered patients); their overall frequency during the registration period increased from zero cases in the initial years (1984-85) to 57 cases in the past 3 years (2006-2008). Crude incidence rate passed from 0.37 in 1986-89 to 10.2 in 2006. Joinpoint trend analysis of crude rates showed a significant increase of incidence during the study period, with percent of annual variation ranging between 38.6% (95% CI 12.5-70.7) and 7.3% (95% CI 2.6-12.1). During the screening period (2005-2008, the past 4 years of registration) there was a significant increase of sessile polyps (p < 0.001), while other clinical and morphological features, including the number of low- and high-risk malignant polyps, remained unchanged. The surgery (after polypectomy) tended to raise both in low- and high-risk subgroups. Conclusion. The incidence of malignant polyps increased significantly from the initial to the most recent periods of colorectal cancer registration. Screening was associated with changes in gross morphology of polyps and with an increased use of the surgery after endoscopic polypectomy.
    Scandinavian Journal of Gastroenterology 09/2013; DOI:10.3109/00365521.2013.838301 · 2.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The pathological reporting of malignant colorectal polyps plays an important role in determining whether definitive surgical resection is required following endoscopic polypectomy. This study aims to assess the adequacy of reporting on malignant polyp specimens at Auckland Hospital and whether synoptic reporting results in an improvement. The pathology database at Auckland Hospital was accessed using a search strategy to identify all malignant polyps diagnosed between 1999 and 2011. Pathology reports were reviewed retrospectively. In total 121 malignant polyps were found. Of these, 73 were colonoscopic polypectomies, 41 were colectomy specimens, and seven transanal resections. Of the 41 colectomy specimens, 19 (46%) were reported in synoptic format compared with none of the colonoscopic polypectomies or transanal resections. The status of the margin of excision, differentiation, and presence of lymphovascular invasion were given in 100% of synoptic reports compared with 51% of non-synoptic reports. Synoptic reporting does improve the completeness of pathological reporting in malignant colorectal polyps. Currently none of the colonoscopically excised malignant polyps are reported in this format at Auckland Hospital. The development and routine use of a synoptic system for reporting on malignant polyps would give clinicians more information on which to base decisions.
    The New Zealand medical journal 01/2013; 126(1382):78-86.
  • Source
    Colorectal Disease 08/2013; 15 Suppl 2:1-38. DOI:10.1111/codi.12262 · 2.02 Impact Factor