An Atlas of the Nonpolypoid Colorectal Neoplasms in Inflammatory Bowel Disease

The role of endoscopy in the management of patients with inflammatory bowel disease (IBD) is well established. However, recent data have shown significant limitations in the effectiveness of colonoscopy in preventing colorectal cancer (CRC) in patients with IBD colitis. The current standard random biopsy seemed largely ineffective in detecting nonpolypoid colorectal neoplasms. Data using chromoendoscopy with targeted biopsy, however, showed a significant improvement when used to detect dysplasia, the best predictor of CRC risk. This article provides a useful and organized series of images of the detection, diagnosis and management of the superficial elevated, flat, and depressed colorectal neoplasms in IBD patients, and provides a technical guide for the use of chromoendoscopy with targeted biopsy.

Key points

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Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer (CRC).
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Studies suggest that the current standard of colonoscopy surveillance with random biopsies to detect dysplasia in IBD patients is inadequate.
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With the use of current knowledge, technology and techniques most dysplasia in IBD patients is visible during colonoscopy.
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Data and guidelines now support the use of chromoendoscopy with targeted biopsy in the detection of dysplasia and/or colorectal cancer in patients with colitic IBD.

Introduction

The role of endoscopy in the management of patients with inflammatory bowel disease (IBD) is well established. However, recent data have shown significant limitations in the effectiveness of the use of colonoscopy to prevent colorectal cancer (CRC) in patients with IBD colitis. The current standard using random biopsy appeared to be largely ineffective in detecting the nonpolypoid colorectal neoplasms (NP-CRN). Data using chromoendoscopy with targeted biopsy, however, showed a significant improvement when used to detect dysplasia, the best predictor of colorectal cancer risk. The purpose of this monograph is to provide the medical profession with a useful and organized series of images showing the superficial elevated, flat, and depressed colorectal neoplasms and their appearance after the application of the technique of chromoendoscopy.

Fig. 1. Endoscopic view of nonpolypoid colorectal neoplasm.

Fig. 2. Current surveillance against CRC is associated with a high risk of interval cancer. In a study of 55,000 Medicare patients diagnosed with CRC, patients with IBD were 3 times more likely to have had a recent colonoscopy than patients without IBD. A significant fraction (15%) of the IBD patients who were diagnosed with CRC had undergone surveillance colonoscopy in the prior 3 years. Note that many of these cancers were advanced. These data indicate that the standard method used during surveillance colonoscopy, namely the random biopsy technique, is inadequate.

Fig. 3. Random biopsy without interpreting what is being viewed is not effective. This example shows that random biopsy of the colon to detect and diagnose dysplasia has a high miss rate. In this patient, random biopsies were taken from the circled areas, as shown by the blood. Unfortunately the neoplasia ( encircled by the dashed line ) was not biopsied. Note that the high-definition adult colonoscope was used, and the lesion was not detected. High definition increases the resolution of the image. For example, high definition captures at least 720 pixels from top to bottom (with most capturing 1080 pixels), whereas standard definition captures 480 pixels. What is needed, however, is not only increased resolution, but also improved contrast between dysplastic and nondysplastic mucosa. If the dysplasia can be highlighted or colored distinctly, its detection and diagnosis may be easier.

Fig. 4. An example of an interval cancer in a patient with ulcerative colitis. This patient was referred to the authors 1 year after image ( A ) was taken. He presented for staging endoscopic ultrasonography after a repeat surveillance showed an ulcerated mass lesion ( B ). The lesion had become an advanced cancer. He underwent a total proctocolectomy. T2, N2 poorly differentiated carcinoma was found.

Fig. 5. Chromoendoscopy facilitates visualization of NP-CRN. ( A ) The lesion was difficult to appreciate with high-definition white-light endoscopy. A possible flat lesion was noted retrospectively, as shown by the white arrowheads. ( B ) The patient presented for follow-up 6 months later. A possible superficial elevated lesion was noted ( blue arrowheads ). ( C ) After application of dilute indigo carmine, the lesion and its borders were easily detected.

Fig. 6. NP-CRN are relatively common in patients with long-standing ulcerative colitis. Jaramillo and colleagues studied the yield of performing chromoendoscopy in patients with extensive and long-standing ulcerative colitis, and found that most neoplasms were flat. The detection of these superficial elevated, flat, or depressed neoplasms, however, poses a special challenge because the background mucosa is often scarred or inflamed. HGD, high-grade dysplasia; LGD, low-grade dysplasia; UC, ulcerative colitis.

Fig. 7. Most colorectal neoplasms in colitic IBD are believed to be visible. A lesion might be considered an “invisible” neoplasm because it was not recognized during the examination. The lesion shown in ( A ), despite being photographed en face, was not recognized as a superficial elevated lesion with an ulcer. The endoscopist missed the lesion again during a repeat surveillance colonoscopy 5 months later, which was performed to survey a pedunculated polyp resection site. The patient, who has long-standing Crohn’s colitis, presented to the authors 14 months later for surveillance colonoscopy. A similar-appearing lesion was easily detected using chromoendoscopy ( B ). Understanding the appearance of the NP-CRN and the signs of its presence are critical to performing an efficacious colonoscopy.

Fig. 8. Understanding the techniques useful to visualize NP-CRN is important, as NP-CRN in patients with colitic IBD can be very difficult to detect. This patient with Crohn’s colitis had endoscopic mucosal resection (EMR) of a superficial elevated NP-CRN. The pathology of the lesion showed low-grade dysplasia (LGD). However, the biopsies of the surrounding mucosa also showed LGD. Thus, he was referred for further evaluation. In ( A ), a slightly more reddish mucosa was seen ( open arrows ). Chromoendoscopy with indigo carmine was used to delineate the border of the lesion ( B ). The lesion had a distinct border. It was completely endoscopically resected and found to be LGD. Note that a distal attachment cap was required to push the fold ( double solid arrows ) to examine the area proximal to the fold.