Pattern of Residual Submucosal Involvement after Neoadjuvant Therapy for Rectal Cancer: A Rationale for the Utility of Endoscopic Submucosal Resection.

Background and Objectives: Full-thickness trans anal local excision for tumors with favorable response following neoadjuvant therapy for locally advanced rectal cancer (LARC) is a common strategy for organ preservation, but it could be associated with a high rate of postoperative complications. We describe the incidence and pattern of submucosal involvement in surgical specimens following neoadjuvant therapy for LARC and whether limiting local excision of the residual tumor bed to only mucosal/submucosal layers of the rectal wall is sufficient for accurately predicting the ypT status of residual cancer, providing a pathological rationale to replace full-thickness local excision by endoscopic submucosal resection. Materials and Methods: This was a single-institution retrospective study conducted at a teaching community hospital. We reviewed clinical and pathological findings with slides of 82 patients diagnosed with LARC treated at our center between 2006 and 2020. Eligibility criteria mirrored our current organ preservation trials. Results: No tumor was found in surgical specimens in 28 cases (34%). Additionally, 4, 22, 27, and 1 cases were staged as ypT1, ypT2, ypT3, and ypT4, respectively. Residual malignant cells were found in the submucosal layer in 98% of cases with ypT+ stage, with 'skip lesions' in only 2% of cases. Conclusions: A very high incidence of submucosal involvement is noticed in residual tumors after neoadjuvant therapy, providing pathological rationale to study the role of endoscopic submucosal resection as a restaging tool for tumors with favorable response after neoadjuvant therapy when organ preservation strategy is pursued. This study was limited by its retrospective design and relatively small number of patients.

Esophageal Schwannoma: An Important Differential Diagnosis for Esophageal Subepithelial Lesions.

Esophageal schwannoma is a rare tumor and is classified as one of the esophageal subepithelial lesions (SELs). Endoscopic ultrasound (EUS) evaluation is the gold standard for evaluating subepithelial lesions. Differentiation through EUS-guided fine needle aspiration is sometimes important to exclude lesions with malignant potential. Immunohistochemistry differentiates schwannoma from other subepithelial lesions. Strong and diffuse positivity for S100 is characteristic. The decision for conservative management versus endoscopic or thoracoscopic intervention is made based on the tumor size, location, and symptoms.

Pancreatic Plasmacytoma: A Case of Recurrent Disease.

Pancreatic plasmacytoma is a rare entity of extramedullary plasmacytomas (EMP). It is important to consider pancreatic plasmacytoma in patients diagnosed with multiple myeloma (MM) presenting with obstructive jaundice. We present a case of pancreatic plasmacytoma in a patient with previously diagnosed multiple myeloma and extramedullary plasmacytoma in remission. Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) were of great diagnostic and therapeutic value for acute management.

Impact of Artificial Intelligence on Miss Rate of Colorectal Neoplasia.

BACKGROUND & AIMS: Artificial intelligence (AI) may detect colorectal polyps that have been missed due to perceptual pitfalls. By reducing such miss rate, AI may increase the detection of colorectal neoplasia leading to a higher degree of colorectal cancer (CRC) prevention. METHODS: Patients undergoing CRC screening or surveillance were enrolled in 8 centers (Italy, UK, US), and randomized (1:1) to undergo 2 same-day, back-to-back colonoscopies with or without AI (deep learning computer aided diagnosis endoscopy) in 2 different arms, namely AI followed by colonoscopy without AI or vice-versa. Adenoma miss rate (AMR) was calculated as the number of histologically verified lesions detected at second colonoscopy divided by the total number of lesions detected at first and second colonoscopy. Mean number of lesions detected in the second colonoscopy and proportion of false negative subjects (no lesion at first colonoscopy and at least 1 at second) were calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) were adjusted by endoscopist, age, sex, and indication for colonoscopy. Adverse events were also measured. RESULTS: A total of 230 subjects (116 AI first, 114 standard colonoscopy first) were included in the study analysis. AMR was 15.5% (38 of 246) and 32.4% (80 of 247) in the arm with AI and non-AI colonoscopy first, respectively (adjusted OR, 0.38; 95% CI, 0.23-0.62). In detail, AMR was lower for AI first for the ≤5 mm (15.9% vs 35.8%; OR, 0.34; 95% CI, 0.21-0.55) and nonpolypoid lesions (16.8% vs 45.8%; OR, 0.24; 95% CI, 0.13-0.43), and it was lower both in the proximal (18.3% vs 32.5%; OR, 0.46; 95% CI, 0.26-0.78) and distal colon (10.8% vs 32.1%; OR, 0.25; 95% CI, 0.11-0.57). Mean number of adenomas at second colonoscopy was lower in the AI-first group as compared with non-AI colonoscopy first (0.33 ± 0.63 vs 0.70 ± 0.97, P < .001). False negative rates were 6.8% (3 of 44 patients) and 29.6% (13 of 44) in the AI and non-AI first arms, respectively (OR, 0.17; 95% CI, 0.05-0.67). No difference in the rate of adverse events was found between the 2 groups. CONCLUSIONS: AI resulted in an approximately 2-fold reduction in miss rate of colorectal neoplasia, supporting AI-benefit in reducing perceptual errors for small and subtle lesions at standard colonoscopy. CLINICALTRIALS: gov, Number: NCT03954548.

Endoscopic full-thickness resection of polyps involving the appendiceal orifice: a multicenter international experience.

BACKGROUND: Endoscopic resection of lesions involving the appendiceal orifice remains a challenge. We aimed to report outcomes with the full-thickness resection device (FTRD) for the resection of appendiceal lesions and identify factors associated with the occurrence of appendicitis. METHODS: This was a retrospective study at 18 tertiary-care centers (USA 12, Canada 1, Europe 5) between November 2016 and August 2020. Consecutive patients who underwent resection of an appendiceal orifice lesion using the FTRD were included. The primary outcome was the rate of R0 resection in neoplastic lesions, defined as negative lateral and deep margins on post-resection histologic evaluation. Secondary outcomes included the rates of: technical success (en bloc resection), clinical success (technical success without need for further surgical intervention), post-resection appendicitis, and polyp recurrence. RESULTS: 66 patients (32 women; mean age 64) underwent resection of colonic lesions involving the appendiceal orifice (mean [standard deviation] size, 14.5 (6.2) mm), with 40 (61 %) being deep, extending into the appendiceal lumen. Technical success was achieved in 59/66 patients (89 %), of which, 56 were found to be neoplastic lesions on post-resection pathology. Clinical success was achieved in 53/66 (80 %). R0 resection was achieved in 52/56 (93 %). Of the 58 patients in whom EFTR was completed who had no prior history of appendectomy, appendicitis was reported in 10 (17 %), with six (60 %) requiring surgical appendectomy. Follow-up colonoscopy was completed in 41 patients, with evidence of recurrence in five (12 %). CONCLUSIONS: The FTRD is a promising non-surgical alternative for resecting appendiceal lesions, but appendicitis occurs in 1/6 cases.

A Case of Esophageal Plasmablastic Lymphoma With a Literature Review.

Plasmablastic lymphoma is a rare B-cell lymphoma that is mainly associated with immunocompromised patients, such as those affected with human-immunodeficiency virus (HIV) or those who have received solid organ transplants; however, it has also been documented in immunocompetent patients. Moreover, there is also a strong association with Epstein-Barr virus (EBV). Although mainly found in the oral cavity, a few cases were documented to affect the gastrointestinal tract, and of those, only three cases were found to involve the esophagus, and we present the fourth case in a 48-year-old HIV-positive male.

Pre-Operative Predictors of Concurrent Choledocholithiasis in Patients With Acute Calculus Cholecystitis: An External Validity Analysis.

Introduction Patients that are presented with acute calculus cholecystitis (AC) and elevated liver enzymes markers (LEM), often require evaluation for concurrent choledocholithiasis (CDL). Currently, evaluation guidelines follow the American Society of Gastroenterology Endoscopy (ASGE) recommendations. Objectives The aim of the study was to externally validate both ASGE and the Chisholm predictors in a community hospital patient cohort. Methods We conducted a retrospective study of patients who presented to Ascension Saint John hospital with AC and elevated LEM over a period of two years. Sensitivity (SEN), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were used to test the external validity of ASGE and Chisholm algorithms. Results A total of 132 patients' charts were reviewed, and 87 patients included. Chisholm predictors SEN, SP, PPV and NPV were 50%, 82%, 18%, and 95% respectively versus 100%, 19%, 8%, 100% for the ASGE predictors model. In the ASGE module, SP and PPV can be significantly improved to 60% and 13%, respectively, by changing a few risk categories including age and LEM range. Conclusions External validation of the Chisholm module in our patient cohort showed that it would lead to a low referral rate for unnecessary imaging and thus might be more cost-effective, especially when compared to current ASGE recommendations which would have a higher referral rate. On the other hand, current ASGE recommendations successively labeled all the patients with CDL, while the Chisholm module missed around 50 percent. We also observed that with the current ASGE module, the referral rate for further imaging and diagnostic tests can be possibly improved by adjusting a few of the predictors including the age and the abnormal liver transaminases range, but this observation is arbitrary and will need to be validated in a larger cohort study.

Full-thickness resection device (FTRD) for treatment of upper gastrointestinal tract lesions: the first international experience.

Background and study aims The Full-Thickness Resection Device (FTRD) provides a novel treatment option for lesions not amenable to conventional endoscopic resection techniques. There are limited data on the efficacy and safety of FTRD for resection of upper gastrointestinal tract (GIT) lesions. Patients and methods This was an international multicenter retrospective study, including patients who had an endoscopic resection of an upper GIT lesion using the FTRD between January 2017 and February 2019. Results Fifty-six patients from 13 centers were included. The most common lesions were mesenchymal neoplasms (n = 23, 41 %), adenomas (n = 7, 13 %), and hamartomas (n = 6, 11 %). Eighty-four percent of lesions were located in the stomach, and 14 % in the duodenum. The average size of lesions was 14 mm (range 3 to 33 mm). Deployment of the FTRD was technically successful in 93 % of patients (n = 52) leading to complete and partial resection in 43 (77 %) and 9 (16 %) patients, respectively. Overall, the FTRD led to negative histological margins (R0 resection) in 38 (68 %) of patients. A total of 12 (21 %) mild or moderate adverse events (AEs) were reported. Follow-up endoscopy was performed in 31 patients (55 %), on average 88 days after the procedure (IQR 68-138 days). Of these, 30 patients (97 %) did not have any residual or recurrent lesion on endoscopic examination and biopsy, with residual adenoma in one patient (3 %). Conclusions Our results suggest a high technical success rate and an acceptable histologically complete resection rate, with a low risk of AEs and early recurrence for FTRD resection of upper GIT lesions.

A Case of A Mesenteric Cyst Mimicking a Biloma.

Mesenteric cysts are a rare entity, with approximately 1,000 cases reported in the literature. Its etiology is unknown but was theorized to be a benign ectopic lymphatic proliferation in the mesentery. Imaging with surgical excision and pathologic microscopic evaluation is needed for diagnosis, but no specific guidelines for its management have been documented. Per most cases in the literature, drainage of mesenteric cysts is suboptimal and associated with increased risk of recurrence and infection, making surgical resection the treatment of choice. With its varying locations and presentations, diagnosis can be tricky especially given the rarity of its occurrence. Differential diagnosis includes pancreatic pseudocyst, hemangioma, choledochal cyst, hydatid cyst, cystic teratoma, etc. We present a 35-year-old woman who came in with worsening right upper quadrant (RUQ) pain due to chronic cholelithiasis and was found to have a large RUQ cystic mass adherent to the gallbladder, suggesting possible biloma or pancreatic pseudocyst; however, tissue analysis was positive for a mesenteric cyst.

Efficacy and Safety of Lumen-Apposing Stents for Management of Pancreatic Fluid Collections in a Community Hospital Setting.

BACKGROUND/AIMS: Endoscopic ultrasound-guided transmural drainage and necrosectomy employing lumen-apposing metal stent (LAMS) are used for treating pancreatic fluid collections (PFCs) with excellent results from academic centers. Herein, we report the efficacy and safety of LAMS in the treatment of PFCs at a community hospital. METHODS: We retrospectively reviewed the etiology of pancreatitis, type and size of PFCs, length of procedure, technical success, clinical success, adverse events, and stent removal. The primary outcome was the rate of clinical success, and secondary outcomes were technical success and adverse events. RESULTS: Twenty-seven patients with a mean age of 54.1±6.5 years were included, 44% of which were men. The mean size of the PFCs was 9.7±5.0 cm (range, 3-21). The most common etiology of pancreatitis was alcohol (44%) followed by idiopathic causes (30%) and presence of gallstones (22%). The diagnosis was pseudocyst in 44.4% (12/27) and walled off necrosis in 55.6% (15/27) of patients. There was 100% technical success without any complications. Clinical success was achieved in 22 of 27 patients (81.5%) who underwent stent removal. CONCLUSION: Our study is the first to report that endoscopic therapy of PFCs using LAMS is safe and effective even in a community hospital setting with limited resources and support compared to large academic centers.

Metastatic Testicular Choriocarcinoma: An Unusual Cause of Upper Gastrointestinal Bleed.

Testicular cancer is the most common neoplasia in men between the ages of 15 to 44 years. Choriocarcinoma represents less than 2% of testicular tumors. It is usually characterized by an early hematogenous spread to the lungs and brain. Metastases to the gastrointestinal (GI) tract are extremely rare. Most metastatic lesions in the GI tract are seen in the small bowel. We present a 30-year-old African American male with a past medical history significant for stage III non-seminomatous germ cell testicular cancer. The patient was initially started on chemotherapy; however, he was not compliant with his treatment. One year following his diagnosis, he presented to the hospital with shortness of breath and chest pain. CT angiography of the chest was done and showed multiple masses scattered in all lung fields. The lesions were believed to be metastatic in nature. Laboratory testing showed a human chorionic gonadotropin beta level of 40,453 IU/L, LDH 258 IUnits/L, and alfa-fetoprotein 8.9 ng/mL. His hospital stay was complicated with melena and a drop in his hemoglobin from a baseline of 12 to 7 gm/dL. An esophagogastroduodenoscopy (EGD) showed three erythematous friable nodules in the gastric body. Biopsy results came back consistent with metastatic choriocarcinoma. The patient was offered salvage chemotherapy; however, he refused treatment and elected to proceed with suppurative measures. Testicular choriocarcinomas are the most aggressive and rapidly arising germ cell tumors. By the time they are diagnosed, large subsets of cases have already metastasized. Patients usually present with symptoms of hemorrhage in metastatic sites due to the high level of vascularization of those lesions. Gastrointestinal metastases from choriocarcinomas are very rare which account for 5% of all metastatic lesions with around 1% affecting the stomach. The presenting symptoms of stomach metastases are melena and/or hematemesis along with anemia. Although extremely rare, gastric metastases of choriocarcinoma should be kept in mind as part of the differential diagnosis for young patients with upper GI bleeding.

A Guidewire May Save the Day.

Endoscopic gallbladder drainage (EGBD) has been used to treat acute cholecystitis or to relieve malignant biliary obstruction as an alternative to percutaneous gallbladder drainage and patient's are poor surgical candidates. This is currently being performed by placement of lumen apposing metallic stent (LAMS) with electrocautery mounted tip delivery system also called as "hot" technique. We had reported a case of self-expanding metallic stent (SEMS) within LAMS after stent migration during EGBD using "hot" technique and propose routine use of guidewire in patients undergoing the procedure.

Endoscopic Treatment of Colonic Duplication Cyst: A Case Report and Review of the Literature.

Colonic duplication cysts are a rare congenital abnormality commonly presenting before two years of age. In adults, it has been rarely reported, most often as an incidental finding. We report a case of 42-year-old female complaining of constipation and lower abdominal pain. Patient's CT scan of the abdomen showed a cystic lesion at hepatic flexure and the diagnosis was confirmed endoscopically using endoscopic ultrasound (EUS). The cyst was treated employing hot snare to expose the cyst cavity. On our literature search, there have been no reported cases of colonic duplication cyst treated endoscopically. We here discuss incidence, diagnosis, characteristics, and treatment of duplication cysts with special emphasis on endoscopic therapy.

The diagnosis and staging of pancreatic cancer: A comparison of endoscopic ultrasound and computed tomography with pancreas protocol.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer-related death in United States. We compared Computed Tomography (CT) with pancreas protocol and Endoscopic Ultrasound (EUS) in terms of mass detection, mass size, vascular involvement and lymph node involvement. METHODS: We retrospectively evaluated 93 patients. Concordance between CT and EUS, and accuracy of CT and EUS were assessed using a retrospective chart review and statistical analysis. RESULTS: CT and EUS agreed on mass detection in 88% of the cases and mass size in 67% of the cases. They agreed in 74% of cases about the presence or absence of vascular involvement and 82% in lymph node involvement. Cohen's kappa indicated that the concordance between two tests was moderately reliable. CONCLUSION: CT and EUS agree moderately well in identifying characteristics of pancreatic masses, but discrepancies between the two modalities are common, particularly with respect to involvement of specific blood vessels and lymph nodes. Clinicians should use caution in relying on a single modality to make decisions.