Endoscopic Evaluation of PET/CT Abnormalities in the Gastrointestinal Tract: Yield and Approach.

BACKGROUND: Unexpected hypermetabolic activity is often encountered in the gastrointestinal tract when PET/CT is performed for various indications, prompting endoscopic evaluation. Our aim was to characterize the types of lesions seen in segments of the gastrointestinal tract with unexpected PET/CT abnormalities as well as clinically significant lesions seen on endoscopy which did not produce a PET/CT abnormality to guide the endoscopist tasked with evaluating these imaging findings. METHODS: We retrospectively reviewed a database of endoscopies performed at City of Hope Comprehensive Cancer Center between January 1, 2016 and September 30, 2021 for an indication of "abnormal PET." We divided the gastrointestinal tract into segments and defined categories of endoscopic/histologic findings for each segment. We counted the number of segments with an abnormal PET/CT finding and corresponding endoscopic/histologic abnormality as well as the number of segments with an endoscopic/histologic abnormality but normal PET/CT. RESULTS: PET/CT identified 209 segments with hypermetabolic activity, 109 of which had corresponding endoscopic/histologic abnormalities. In the jejunum and ileum, all corresponding lesions were malignant. Seventy-three percent of corresponding lesions in the stomach were H. pylori positive. PET/CT failed to detect 34.7% of clinically significant lesions diagnosed endoscopically, including 1 malignancy in the transverse colon and many inflammatory or low-risk premalignant lesions. CONCLUSION: PET/CT abnormalities seen in the small bowel should be evaluated urgently as nearly all correlates were malignant, while abnormalities in the stomach should prompt workup for H. pylori. Most lesions missed by PET/CT were inflammatory or low-risk premalignant yet clinically significant, confirming the need to inspect the entirety of the upper or lower gastrointestinal tract during endoscopy.

Computed Tomography Angiography and Conventional Angiography for the Diagnosis and Treatment of Non-variceal Gastrointestinal Bleeding at a Tertiary Cancer Center.

INTRODUCTION: To evaluate the diagnostic value of computed tomography angiography (CTA) and conventional angiography (CA) and the therapeutic value of transarterial embolization for acute gastrointestinal bleeding in patients with malignancy. METHODS: A retrospective review of 100 patients who underwent CTA and/or CA for gastrointestinal bleeding at a comprehensive cancer center between the years 2011-2021 was performed. Clinical and patient outcome data were collected and analyzed using Kruskal-Wallis tests for continuous variables and chi-square tests or Fisher's exact tests (whichever is appropriate) for categorical variables in univariate analysis. All tests were two-sided at a significance level of 0.05. Analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC). RESULTS: Fifty-two percent of our patients underwent CTA alone, 29% underwent CA alone, and 19% underwent both procedures. Overall, CTA was positive in 11.3% (8/71) of patients and CA was positive in 22.9% (11/38) of patients. Of patients who underwent both studies, 52.6% (10/19) were positive for both. ICU admission was associated with CTA and/or CA positivity (p=0.015). Of 48 patients with data for embolization, 50% of patients underwent transarterial embolization for bleeding, 11 patients had identifiable bleeding on CA, and 13 patients underwent prophylactic embolization at the site of suspected bleeding. Rebleeding following embolization was found in 33.3% (8/24) of patients, including six patients who underwent prophylactic embolization and two patients who were treated for visualized bleeding. CONCLUSION: CTA and CA are two critical studies for patients with GI bleeding and a history of malignancy. Neither alone can effectively exclude an identifiable source of bleeding. In patients with a history of malignancy, transarterial embolization may be an effective treatment of both angiographically visible and occult sources of GI bleeding.

Flexible sigmoidoscopy may be sufficient for initial evaluation of suspected immunotherapy-mediated colitis: A cross-sectional study.

BACKGROUND AND AIM: Immune checkpoint inhibitors (ICIs) have shown promise in treating a variety of cancers. Their increased use coincides with increased incidence of immunotherapy-mediated colitis (IMC), a common adverse effect. Optimal strategy for endoscopic evaluation of IMC (full colonoscopy or flexible sigmoidoscopy) is not well-defined. METHODS: Retrospective review of all patients at City of Hope referred to gastroenterology for evaluation of IMC due to gastrointestinal symptoms was performed. Patients with an existing histologic diagnosis of IMC established at an outside hospital or a diagnosis of infectious or chronic colitis were excluded. RESULTS: We identified 51 symptomatic patients on ICIs prompting evaluation for IMC with colonoscopy (47/51) or flexible sigmoidoscopy (4/51). All distal rectosigmoid biopsies during flexible sigmoidoscopy demonstrated histologic evidence of IMC. In full colonoscopy, IMC was either present in all segments of colon simultaneously (35/47) or absent from all segments (12/47). No isolated proximal colonic biopsies demonstrated IMC. Endoscopically normal mucosa demonstrated histologic evidence of IMC up to 68.6% of the time. Endoscopically abnormal right, transverse, and left colon had low sensitivity (35.3%, 34.3%, and 41.7%, respectively) and high specificity (100.0%, 100.0%, and 91.7%, respectively) for histological presence of IMC. CONCLUSIONS: Distal colon biopsies in patients on ICI therapy with diarrhea and suspected IMC were sufficient for diagnosing IMC in our cohort. Further, we found histologic evidence of IMC in biopsies taken from normal-appearing mucosa in a number of patients, suggesting that a normal endoscopic appearance does not preclude the presence of IMC and biopsies should be taken from both normal and abnormal-appearing mucosa.

Episodic, severe abdominal pain due to isolated jejunal Crohn's disease.

Small bowel Crohn's disease can present with episodic, relapsing, and remitting symptoms and delays in the diagnosis are common. We present a case of a young woman with three years of intermittent abdominal pain and nausea with negative previous evaluations. On presentation, inflammatory markers were elevated, and repeat imaging showed jejunal inflammation, with histopathological examination showing non-caseating granulomas of the small bowel consistent with Crohn's disease. This case highlights the importance of gastroenterologist recognizing the alarm signs in a patient with unexplained symptoms and adds to the literature on the clinical presentation of a rare diagnosis of isolated jejunal Crohn's disease.

Impact of observational training on endoscopic mucosal resection outcomes and competency for large colorectal polyps: single endoscopist experience.

Background and study aims Endoscopic mucosal resection (EMR) is standard treatment for large colorectal polyps. However, it is a specialized technique with limited data on the effectiveness of training methods to acquire this skill. The aim of this study was to evaluate the impact of observational training on EMR outcomes and competency in an early-stage endoscopist. Patients and methods A single endoscopist completed comprehensive EMR training, which included knowledge acquisition and direct observation of EMR cases, and proctored supervision, during the third year of gastroenterology fellowship. After training, EMR was independently attempted on 142 consecutive, large (i. e., ≥ 20 mm), non-pedunculated colorectal polyps between July 2014 and December 2017 (mean age 61.7 years; mean polyp size 30.4 mm; en-bloc resection 55 %). Surveillance colonoscopy for evaluation of residual neoplasia was available for 86 % of the cases. Three primary outcomes were evaluated: endoscopic assessment of complete resection, rate of adverse events (AEs), and rate of residual neoplasia on surveillance colonoscopy. Results Complete endoscopic resection was achieved in 93 % of cases, the rates of AEs and residual neoplasia were 7.8 % and 7.3 %, respectively. The rate of complete resection remained stable (at 85 % or greater) with increasing experience while rates of AEs and residual neoplasia peaked and decreased after 60 cases. Conclusions An early-stage endoscopist can acquire the skills to perform effective EMR after completing observational training. At least 60 independent EMRs for large colorectal polyps were required to achieve a plateau for clinically meaningful outcomes.

Hereditary Polyposis Syndromes.

PURPOSE OF REVIEW: Colorectal cancer (CRC) is the third most common cancer in the USA and inherited cancer syndromes are responsible for approximately 3-5% of all CRCs. Genetic testing costs have plummeted in recent years; however, awareness and referral of high-risk patients for testing is still very low. We review the salient clinical features, genetics, and management of well-defined gastrointestinal (GI) hereditary polyposis syndromes including familial adenomatous polyposis, MUTYH-associated polyposis, and the hamartomatous polyposis syndromes. RECENT FINDINGS: Comprehensive endoscopic surveillance has the potential to prevent the development of GI cancer and to identify early-stage cancer; newer developments like high-definition endoscopes, chromoendoscopy, and the use of cap-assisted endoscopy have shown promise for enhanced lesion detection rates. Several chemoprevention trials have yielded promising results but safety and efficacy data for long-term use is still awaited. Several new polyposis genes have also been identified in the recent years. Multiple societies have recently published updated surveillance guidelines to aid clinicians in the detection and management of patients with hereditary GI polyposis syndromes. Although these syndromes are rare, it is crucial for the clinicians to recognize these in a timely manner, for the appropriate management plans for both the patient and their at risk family members.

Effect of I-scan Electronic Chromoendoscopy on Detection of Adenomas During Colonoscopy.

BACKGROUND & AIMS: I-scan is an electronic chromoendoscopy technology that improves resolution of epithelial and mucosal surfaces and vessels. We performed a randomized controlled trial to compare detection of adenomas by i-scan vs standard high-definition white-light (HDWL) colonoscopy. METHODS: From February 1 through December 31, 2017, 740 outpatients (50-75 years old) undergoing screening and surveillance for colorectal neoplasia were randomly assigned to groups that received colonoscopies with i-scan 1 (surface and contrast enhancement) or HDWL. When lesions and polyps were detected, endoscopists could switch between i-scan 1 and HDWL imaging to confirm their finding; polyps were collected and analyzed by histology. The primary outcome was adenoma detection rate (ADR, proportion of subjects with at least 1 adenoma of any size); secondary outcomes included detection of sessile serrated polyps and neoplasias, along with location, size, and morphology of polyps. We performed intent to treat and per-protocol analyses (on 357 patients evaluated by i-scan and 358 evaluated by HDWL colonoscopy) to assess the primary and secondary outcomes. RESULTS: There were no differences in baseline characteristics between the groups. In the intent to treat analysis, the ADR was significantly higher in the i-scan 1 group (47.2%) than in the HDWL colonoscopy group (37.7%) (P = .01). In the per-protocol analysis, the ADR in the i-scan 1 group (47.6%) was also significantly higher than in the HDWL group (37.2%) (P = .005), but this effect was not consistent among all endoscopists. There was no difference between groups in detection of sessile serrated polyps. However, the rate of neoplasia detection was significantly higher in the i-scan 1 group (56.4%) than in the than the HDWL group (46.1%) (P = .005). In secondary analyses, the increase in ADR was associated with improved detection of diminutive flat adenomas in the right colon. CONCLUSION: In a prospective randomized trial, higher proportions of patients with adenomas were identified in a group that underwent colonoscopy with i-scan 1 than in a group evaluated by HDWL colonoscopy. This effect was mainly due to improved detection of diminutive, flat right sided adenomas. I-scan 1 technology may benefit some endoscopists. ClinicalTrials.gov no: NCT02811419.

Novel variant of unknown significance in MUTYH in a patient with MUTYH-associated polyposis: a case to reclassify.

MUTYH-associated polyposis (MAP) is a hereditary cancer syndrome that is caused by biallelic pathogenic variants in the MUTYH gene and should be evaluated for in patients with an attenuated colonic polyposis phenotype. Monoallelic pathogenic variants in MUTYH are associated with a moderate increased risk of colorectal cancer but not with the polyposis phenotype. We present a case of a patient presenting with multiple colonic adenomatous polyps, whose germline testing revealed a heterozygous pathogenic variant in MUTYH in exon 13, c.1187G > A (p.Gly396Asp) as well as a heterozygous variant of unknown significance (VUS) in MUTYH in exon 14, c.1379T > C (p.Leu460Ser). We interpret the VUS as pathogenic in light of the patient's phenotype; the fact that the VUS was in trans with a known pathogenic variant; and because all the in silico predictors suggested, it was likely to be deleterious. This case highlights the importance of a gastroenterologist recognizing the indication for genetic testing in a patient with greater than ten adenomas, the importance of a genetic counselor in interpretation of results, and is the first report of the specific variant in the literature with clinical information to suggest that it is likely pathogenic.

Endoscopy is of low yield in the identification of gastrointestinal neoplasia in patients with dermatomyositis: A cross-sectional study.

AIM: To determine the prevalence of gastrointestinal neoplasia among dermatomyositis patients who underwent an esophagogastroduodenoscopy and/or colonoscopy. METHODS: A cross-sectional study examining the results of upper endoscopy and colonoscopy in adults with dermatomyositis at an urban, university hospital over a ten year period was performed. Chart review was performed to confirm the diagnosis of dermatomyositis. Findings on endoscopy were collected and statistical analyses stratified by age and presence of symptoms were performed. RESULTS: Among 373 adult patients identified through a code based search strategy, only 163 patients had dermatomyositis confirmed by chart review. Of the 47 patients who underwent upper endoscopy, two cases of Barrett's esophagus without dysplasia were identified and there were no cases of malignancy. Of the 67 patients who underwent colonoscopy, no cases of malignancy were identified and an adenoma was identified in 15% of cases. No significant differences were identified in the yield of endoscopy when stratified by age or presence of symptoms. CONCLUSION: The yield of endoscopy is low in patients with dermatomyositis and is likely similar to the general population; we identified no cases of malignancy. A code based search strategy is inaccurate for the diagnosis of dermatomyositis, calling into question the results of prior population-based studies. Larger studies with rigorously validated search strategies are necessary to understand the risk of gastrointestinal malignancy in patients with dermatomyositis.