Specimens from Biopsies of Colorectal Polyps Often Harbor Additional Diagnoses

Hindawi Publishing Corporation Pathology Research International Volume 2013, Article ID 570526, 6 pages http://dx.doi.org/10.1155/2013/570526 Research Article Specimens from Biopsies of Colorectal Polyps Often Harbor Additional Diagnoses Shefali Chopra and Mark Li-cheng Wu Department of Pathology and Laboratory Medicine, University of California Irvine School of Medicine, Irvine, CA 92868, USA Correspondence should be addressed to Mark Li-cheng Wu; Received 26 July 2013; Accepted 13 November 2013 Academic Editor: Oscar Cummings Copyright © 2013 S. Chopra and M. L.-c. Wu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives. The utility of examining specimens from colorectal biopsies of polyps for nonneoplastic diseases is currently unknown. Our objectives were to characterize such additional diagnoses that could be rendered. Methods. We retrospectively and prospectively reviewed specimens from endoscopic biopsies of colorectal polyps obtained during routine screening or surveillance. Results. 17 of 168 specimens (10.1%) contained additional diagnoses, including schistosomiasis, eosinophilic colitis, intestinal spirochetosis, melanosis coli, and other entities. These findings were easily overlooked because they often affected mucosa that was spared by the polyps or were often evident only at high magnification. Schistosomiasis, eosinophilic colitis, and intestinal spirochetosis were clinically occult. Conclusions. Specimens from biopsies of colorectal polyps often harbor other diagnoses, in addition to polyps, and can be simultaneously screened for polyps and examined for nonneoplastic diseases. Detection of other diagnoses in addition to polyps requires awareness, examination at high magnification, and examination of areas spared by the polyps. 1. Introduction 2. Materials and Methods Specimens from endoscopic biopsies of putative colorectal lesions usually show traditional nonserrated adenomas, serrated polyps, or variants of normal mucosa. These entities generally are easily and rapidly diagnosed at low magnification. Consequently, pathologists are tempted to examine these specimens quickly and only at low magnification, to assume that these specimens will harbor only polyps or variants of normal mucosa, and to refrain from examining these specimens further at high magnification once polyps are diagnosed. Directed review of these specimens might reveal other diagnoses, in addition to polyps. Pathologists might overlook such second diagnoses for various reasons. However, such second diagnoses might be significant. We reviewed specimens from biopsies of colorectal polyps to characterize second diagnoses that could be rendered in this setting and to demonstrate that these specimens could be examined for nonneoplastic diseases. The study was approved by the Institutional Review Board of the University of California, Irvine, USA, on November 7, 2005 as protocol HS number: 2005-4646. The study was carried out in 2 phases. The first phase was designed to determine prevalence, and the second phase was designed to determine incidence. During the first phase, consecutive specimens from endoscopic colorectal biopsies of polyps accessioned at our institution during a 1-month interval, from July 1, 2003 to August 1, 2003, were retrospectively reviewed by both of us, who are gastrointestinal pathologists, with special effort to render second diagnoses in addition to polyps. Only specimens that had polyps, broadly defined as protruding pathologic mucosal lesions [1], confirmed histologically were eligible for review. All original diagnoses were made by 5 other pathologists, who were general surgical pathologists. These pathologists were unaware of our study. During the second phase, specimens from 100 consecutive histologically 2 confirmed polyps obtained from endoscopic colorectal biopsies accessioned to 1 of us (M. L.-c. Wu) at our institution during the course of normal signout were prospectively accrued during the interval July 1, 2007–September 11, 2007. These specimens were examined with knowledge of our study and with special effort to render second diagnoses in addition to polyps. For both phases, this special effort consisted of examining all sections on each slide, at low magnification and high magnification, and examining the entire surface area of each section including mucosa affected by polyps and mucosa spared by polyps. Specimens from both phases with additional diagnoses were reviewed by both of us for confirmation. Pathology reports and requisitions for all specimens were reviewed. Corresponding reports from endoscopy were reviewed for each specimen, in either phase, for which additional diagnoses were rendered. Diagnoses were considered clinically occult if the requisitions or corresponding reports from endoscopy lacked the mention of the diagnoses or lacked the mention of findings that could be reasonably attributed to the diagnoses. Excluded from the entire study were specimens from biopsies of putative lesions that lacked polyps histologically. All specimens were processed routinely, formalin-fixed, and paraffin-embedded. All histologic sections were cut 4 microns thick and stained with hematoxylin and eosin. Microscopy was performed with a conventional multiheaded optical microscope (BX45, Olympus, Melville, NY, USA). All diagnoses were rendered according to standard criteria [1–4]. 3. Results For the first phase, 78 specimens were diagnosed as polyps by original pathologists in the 1-month interval. We reclassified 3 hyperplastic polyps and 1 tubular adenoma as normal mucosa and excluded these specimens from further study. We reclassified 1 mucosal prolapse, 1 hyperplastic polyp, and 1 inflammatory polyp, as leiomyoma, sessile serrated adenoma, and tubular adenoma, respectively. We confirmed all other original diagnoses. A few specimens had multiple polyps. The first phase therefore eventually consisted of 74 specimens, with 78 histologically confirmed polyps. These polyps were from 52 patients, ages 43 to 74, including 31 men and 21 women. The 78 polyps included 48 polyps in men and 30 polyps in women. Of the 74 specimens, additional diagnoses were retrospectively detected by us in 7 specimens (9.5%). These diagnoses included the following: mucosal prolapse (Figure 1) (in 2 specimens with hyperplastic polyps and 1 specimen with tubular adenoma), melanosis coli (Figures 2(a) and 2(b)) (in 2 specimens with tubular adenomas), hyperplastic polyp (in 1 specimen with tubular adenoma), and eosinophilic colitis (Figure 3) (in 1 specimen with tubular adenoma). The patient for whom we diagnosed eosinophilic colitis was asymptomatic. With this caveat, we rendered the diagnosis of eosinophilic colitis based on compelling morphology that satisfied recently proposed criteria [3]. Microscopy (...truncated)