Specimens from biopsies of colorectal polyps often harbor additional diagnoses

Abstract

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.

Figure 1

Mucosal prolapse in specimen with hyperplastic polyp. Only small focus of smooth muscle present (left of center) (H&E, ×200).

Figure 2

Melanosis coli in specimen with tubular adenoma. (a) Melanosis affects nonpolypoid mucosa (H&E, ×200) and (b) spares adenoma (H&E, ×200).

Figure 3

Eosinophilic colitis in specimen with tubular adenoma. Nonpolypoid mucosa contains abundant eosinophils in lamina propria, eosinophilic cryptitis, and absence of neutrophils (H&E, ×600).

Figure 4

Schistosomiasis in specimens with adenocarcinoma and hyperplastic polyp. (a) Nonpolypoid mucosa beside adenocarcinoma (not shown) shows schistosomiasis and granuloma (H&E, ×400). (b) Schistosomiasis affects hyperplastic polyp (H&E, ×400) and (c) adjacent, otherwise normal nonpolypoid mucosa (H&E, ×400).

Figure 5

Intestinal spirochetosis in specimen with sessile serrated adenoma. Spirochetes colonize surface of otherwise normal mucosa present beside polyp (top right) and present focally between serrated crypts (top left) (Warthin-Starry, ×200).