Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia.

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

Multiple Ulcers in the Ileum and Lymphadenopathy Following the Usage of Methotrexate in a Patient With Rheumatoid Arthritis: A Case Report.

This case report aims to highlight a rare occurrence of severe anemia and lymphadenopathy secondary to methotrexate (MTX)-induced ileal mucosa damage in a patient with elderly onset rheumatoid arthritis (EORA). We present the case of a 72-year-old female with a history of EORA, treated with MTX, who exhibited hematochezia without accompanying pain, diarrhea, or known infectious contacts. Diagnostic investigations included imaging and endoscopic procedures. The patient's presentation of severe anemia was atypical, given the absence of significant pain or discomfort associated with EORA. The lack of active bleeding observed during endoscopy, coupled with multiple ileal ulcers, suggested a chronic progression of mucosal damage. Laboratory findings, including normal lactate dehydrogenase, soluble interleukin-2 receptor levels, and the absence of malignancy in mucosal biopsies, ruled out MTX-induced lymphoma. The patient's condition improved with the cessation of MTX and the introduction of symptomatic treatment and anemia management. This case underscores the need for vigilant monitoring and comprehensive evaluation in patients with RA, especially the elderly, treated with MTX. It also highlights the importance of considering drug-induced complications in the differential diagnosis of anemia. The case demonstrates the necessity of a personalized approach to treatment, emphasizing regular follow-ups and adjustments based on the patient's response to therapy. This report contributes to the growing body of evidence on the complexities of managing RA in the elderly, particularly regarding the side effects of common medications like MTX.

Endoscopic differential diagnosis between foveolar-type gastric adenoma and gastric hyperplastic polyps in Helicobacter pylori-naïve patients.

BACKGROUND: Foveolar-type gastric adenoma (FGA) occurs in Helicobacter pylori (Hp)-naïve individuals and morphologically mimics Hp-naïve gastric hyperplastic polyp (HpN-GHP). FGA is often difficult to distinguish from HpN-GHP even by biopsy, due to its low-grade histologic atypia. We conducted a retrospective study to create an endoscopic diagnostic index. METHODS: We analyzed 51 FGAs in 41 patients and 36 HpN-GHPs in 24 patients. All lesions were photographed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). Three experts and three non-experts reviewed the WLE and WLE+NBIME images to assess six items for lesion diagnosis. We analyzed correlations between the diagnostic items and histologic features and compared the diagnostic accuracy between modalities. We created a composite diagnostic index and calculated its accuracy and consistency. RESULTS: FGAs more frequently showed the following features vs. HpN-GHPs: bright-red color (94.1% vs. 44.4%), peripheral hyperplasia (58.8% vs. 8.3%), papillary/gyrus-like microstructure (96.1% vs. 33.3%), visible capillaries (70.6% vs. 38.9%), and demarcation line (98.0% vs. 41.7%) (P < 0.05). White-zone thickening was seen only in HpN-GHPs (52.8%). Diagnostic accuracy (mean, WLE vs. WLE+NBIME) was 90.8 ± 1.1% vs. 93.5 ± 2.4% (P = 0.15) for experts and 88.5 ± 3.0% vs. 86.6 ± 3.5% (P = 0.51) for non-experts. When satisfying the four criteria (bright-red color, papillary/gyrus-like microstructure, demarcation line, and absent white-zone thickening), sensitivity and specificity for FGA were 90.2% and 94.4%, respectively, with a kappa value of ≥ 0.6 for interobserver diagnostic agreement. CONCLUSIONS: Composite diagnostic index contributes to the reproducible, accurate, preoperative differential diagnosis of FGA and HpN-GHP.

Timing of Treatment for Cytomegalovirus Infection in an Immunocompetent Middle-Aged Woman With Fulminant Ulcerative Colitis: A Case Report.

Viral infections, such as cytomegalovirus (CMV) infection, may affect the clinical course of ulcerative colitis (UC). CMV can cause chronic inflammation of the intestinal mucosa. In inflammatory bowel disease, chronic inflammation caused by CMV can deter the regeneration of the mucosa of the colon. However, the relationship between CMV and inflammatory bowel disease still needs to be clarified, especially in immunocompetent patients, such as younger patients not treated with immunosuppressants. Herein, we describe our experience with a middle-aged immunocompetent female patient diagnosed with fulminant UC positive for myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA). Her initial response to high-dose prednisolone was favorable; however, remission was not achieved. Immunohistochemical staining revealed the presence of CMV. Subsequently, the patient was successfully treated with prednisolone, adalimumab, and azathioprine, along with the anti-CMV treatment comprising valganciclovir. This case shows that the presence of CMV in the mucosa and blood may make patients with UC refractory to immunosuppression; furthermore, the positivity of MPO-ANCA in patients with UC can necessitate the administration of high-dose immunosuppressants to taper the dose of prednisolone.

Diagnosing Infectious Hepatic Cysts in an Older Patient With Multiple Skin Masses: A Case Report.

Among the most severe complications of hepatic cystic diseases is infectious hepatic cysts (IHCs). IHCs may appear mainly among immunocompromised hosts. However, older patients have a variety of immunological conditions. The detection of the factors suppressing immunity is essential for patients with IHCs. Herein, we present the case of an 86-year-old woman admitted to the emergency department with a fever. We suspected IHCs based on changes in abdominal ultrasound findings. After multiple follow-ups to determine the cause of the fever that was unresponsive to treatment, we discovered debris in the cyst that had not been present at the time of the initial presentation. The patient was subsequently treated with percutaneous transhepatic drainage and tazobactam/piperacillin. The investigation of the causes of immunosuppression clarified the multiple skin masses. The biopsy of the mass clarified diffuse large B cell lymphoma without lymph node swellings. Consecutive ultrasound can detect findings missed during the initial presentation and changes that occur within a short period. The detection of the causes of immunosuppression is essential even among older patients with IHCs for better care among older patients.

Heyde Syndrome Complicated by Essential Thrombocythemia: A Case Report.

Heyde syndrome is a multisystem disorder characterized by the triad of aortic stenosis (AS), gastrointestinal bleeding, and acquired von Willebrand syndrome. Age-related degeneration is the most common cause of aortic stenosis and is frequently encountered in today's aging society. Approximately 20% of patients with severe aortic stenosis have Heyde syndrome. We encountered an older patient with primary thrombocytosis who was brought to a rural community hospital with bloody stools and was diagnosed with bleeding from an intestinal arteriovenous malformation. A final diagnosis of Heyde syndrome was made based on the presence of severe aortic stenosis and the presence of schistocytes in peripheral blood smears. Valvular diseases can complicate chronic hematological diseases. When the rapid progression of anemia and segmented red blood cells in the peripheral blood are observed in patients with severe aortic stenosis, Heyde syndrome should be considered based on peripheral blood smears and clinical course.

Difficulty in Diagnosing Anti-neutrophil Cytoplasmic Antibody-Related Vasculitis With Interstitial Pneumonia and in Ascertaining the Cause of Associated Hematochezia: A Case Report.

The diagnosis of rheumatological diseases is challenging among older patients with multimorbidity. Rheumatological diseases in older patients show varied symptoms, such as fatigue, fever, and appetite loss. We encountered an older woman with anti-neutrophil cytoplasmic antibody (ANCA)-related vasculitis complicated by cytomegalovirus (CMV) infection. The case was further complicated by hematochezia and was eventually diagnosed as CMV infection with adverse reactions to medications. This case highlights the difficulty of diagnosing ANCA-related vasculitis and dealing with the complications arising due to the side effects of therapy.

Possible Macrophage Activation Syndrome Caused by Endoscopic Retrograde Cholangiopancreatography for Bacteremia Due to Chronic Cholelithiasis.

Hypoglycemia is caused by various clinical diseases. Among older patients, occult bacteremia may cause critical illness-related corticosteroid insufficiency (CIRCI), triggering hypoglycemia. Additionally, older patients have various chronic medical and homeostatic conditions. Interventions may be needed when chronic conditions cause clinical diseases and CIRCI. Herein, we report a case of possible macrophage activation syndrome (MAS) caused by endoscopic retrograde cholangiopancreatography for bacteremia due to chronic cholelithiasis in an 85-year-old man. Interventions for chronic conditions could impinge on homeostasis in older patients, causing acute conditions such as MAS. Among older frail patients with chronic conditions, interventions for chronic conditions should be discussed, including the triggering of other acute conditions, such as MAS.

Eosinophilic Gastroenteritis in the Small Intestine Mimicking Eosinophilic Granulomatosis With Polyangiitis in a Young Male Patient.

Eosinophilic gastroenteritis (EGE) is a disease involving the gastrointestinal tract that involves the invasion of eosinophils into the lumen of the tract. Invasion of eosinophils in the tract causes edema and inflammation of the wall, resulting in acute or chronic diarrhea and abdominal pain. EGE can cause chronic inflammation in the small intestine, thereby mimicking chronic vasculitis. We report the case of a 24-year-old male patient with the chief complaint of acute progressive abdominal pain. Endoscopic findings of the small intestine were chronic and similar to those of polyangiitis (eosinophilic granulomatosis with polyangiitis). This case shows the presence of various clinical courses of EGE and the discrepancy between the symptoms and endoscopic appearance of vasculitis. Physicians should focus not only on acute symptoms but also on chronic phases of the disease to prevent disease progression and modify patients' help-seeking behaviors according to their symptoms.

Gallstone Hepatitis Caused by Transient Common Bile Duct Obstruction in a Middle-Aged Woman.

The interpretation of hepatocholangial laboratory test results is challenging. Possible liver biochemical tests include the evaluation of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, 5'-nucleotidase, lactate dehydrogenase, bilirubin, and albumin levels, as well as prothrombin time and international normalized ratio. When liver enzyme levels are elevated, R-values are generally used for diagnosis. A 62-year-old woman presented to our hospital with the chief complaint of abdominal pain and was consequently diagnosed with gallstone hepatitis based on her blood test results. Generally, gallstone hepatitis manifests as elevated liver enzyme levels showing a hepatocellular pattern, while common bile duct obstructions show a cholestatic pattern. Since gallstone hepatitis is indistinguishable from viral and ischemic hepatitis in the early stages of onset, it is vital to monitor changes in symptoms, biochemical tests, and imaging results over time to diagnose this disease.

KLF4 Mutation Shapes Pathologic Characteristics of Foveolar-Type Gastric Adenoma in Helicobacter pylori-Naive Patients.

Along with a recent remarkable decrease in Helicobacter pylori-infected individuals, reports of gastric neoplasms such as sporadic foveolar-type gastric adenoma (FGA) in H. pylori-naive patients have been increasing. This tumor, with its raspberry-like appearance, is common in H. pylori-naive gastric mucosa. The current study investigated the genomic features of sporadic FGA. Fresh-frozen sporadic FGA tissue samples from H. pylori-naive patients were subjected to whole genome analysis using a next-generation sequencer. Proliferation ability and apoptotic profiles of human gastric epithelial cells, along with plasmid transfection of candidate variants, were examined. A mean of 6.65 × 108 total reads were obtained for each sample. Common genetic abnormalities in well-known proliferation driver genes of conventional gastric dysplasia/cancer were not found. However, a common single-nucleotide variation (SNV) was noted within the DNA-binding domain of the tumor suppressor gene KLF4. This novel SNV was located in the zinc finger 2 region. Additional experiments showed that it significantly suppressed proliferation of gastric epithelial cells compared with wild-type KLF4 plasmid-transfected cells, although suppression was reduced in early apoptotic phase-related genes. A novel SNV in the KLF4 zinc finger 2 region was commonly found in sporadic FGA tissue samples, which may explain the slow-growing properties of this neoplasm.

Intestinal-type gastric dysplasia in Helicobacter pylori-naïve patients.

Gastric dysplasia and gastric cancer in Helicobacter pylori (Hp)-naïve patients usually exhibit a gastric phenotype, reflecting gastric mucosa without intestinal metaplasia (IM). We showed that intestinal-type gastric dysplasia (IGD) rarely occurs in the Hp-naïve stomach. In the last 10 years, we treated 1760 gastric dysplasia and gastric cancer patients, with 3.6% (63/1760) being Hp-naïve. Among these, ten were diagnosed with 14 IGDs and enrolled in this retrospective analysis. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We analyzed their endoscopic and microscopic features and patient demographics. Five men and five women aged 64 ± 21 years were included. WLE showed the depressed lesions mimicking a benign raised erosion in the prepyloric compartment. Multiple growths were confirmed in 30% (3/10) of patients. NBIME showed a near-regular microstructure and capillaries in 50% (7/14) of lesions with a gastritis-like appearance. Histologically, background mucosa was non-atrophic pyloric gland tissue, but 40.0% of samples (4/10) contained sporadic IM. Most of the lesions (8/14) were low-grade dysplasia, and others had a high-grade component, with one progressing to intramucosal carcinoma. The neoplastic surface was widely covered with foveolar epithelium in 57.1% (8/14). Immunohistochemically, neoplastic cells expressed CDX2 in all patients (14/14), MUC2 and CD10 in 92.9% (13/14), MUC5AC in 14% (2/14), and no expression of MUC6, showing an intestinal phenotype. Ki-67 was overexpressed with a mean labeling index of 58.3 ± 38.5%, and p-53 was overexpressed in 92.9% (13/14), regardless of the dysplastic grade. The IGD rarely occurs in Hp-naïve patients with distinctive clinicopathologic characteristics.

Evaluations of Gastric Acid Pocket Using Novel Vertical 8-Channel pH Monitoring System and Effects of Acid Secretion Inhibitors.

BACKGROUND/AIMS: The gastric acid pocket has an important role in gastroesophageal reflux disease development. In this study, we utilized a novel 8-channel pH monitoring system with sensor intervals of 1 cm on the vertical axis for evaluation of postprandial gastric acid pocket in healthy Japanese adults, as well as the effects of vonoprazan and rabeprazole. METHODS: Twelve healthy volunteers without Helicobacter pylori infection were enrolled. A catheter was inserted transnasally and positioned under X-ray guidance, then postprandial acid pocket formation was monitored over time in a sitting position. Thereafter, acid pocket changes were assessed following administration of vonoprazan (20 mg) or rabeprazole (20 mg). RESULTS: The gastric acid pocket was successfully measured by use of the present system in 10 cases, while failure occurred in 2 because of inappropriate catheter positioning. Observed acid pockets were visualized with a mean length of 2.2 ± 0.4 channels on the top layer of food contents approximately 20 minutes after finishing a meal. There were some variations for lasting time of the acid pocket. Complete elimination within 3 hours after administration of vonoprazan was noted in all cases. Likewise, following administration of rabeprazole, the acid pocket was eliminated in 7 cases, while acidity was reduced though the pocket remained observable in 3. CONCLUSION: s Gastric acid pocket observations were possible using our novel vertical 8-channel sensor catheter. The present findings showed that vonoprazan strongly suppressed acid secretion within a short period, suggesting its effectiveness for gastroesophageal reflux disease treatment.

Primary Extragastrointestinal Stromal Tumor of Greater Omentum with Intraperitoneal Bleeding.

Gastrointestinal stromal tumors (GISTs) develop in the digestive tract, mainly in the stomach, small intestine, colon, or esophagus. However, primary tumors with the same pathologic features as GISTs have been reported to occur outside of the digestive tract and are called extragastrointestinal stromal tumor (EGIST). We herein report a rare case of EGIST arising from the greater omentum in a patient with abdominal pain caused by intraperitoneal bleeding from the tumor.

Sporadic foveolar-type gastric adenoma with a raspberry-like appearance in Helicobacter pylori-naïve patients.

Sporadic foveolar-type gastric adenoma (FGA) has been described as an extremely rare polyp that is whitish and flatly elevated. However, we recently found that sporadic FGA with a raspberry-like appearance (FGA-RA) is not rare in Helicobacter pylori (H. pylori)-naïve gastric mucosa. We endoscopically or surgically treated 647 patients with gastric epithelial neoplasms in the last 5 years, with 7.7% (50/647) being H. pylori-naïve. Among these, 43 FGA-RAs were diagnosed based on histologic and endoscopic features in 34 patients, who were all enrolled in this retrospective study. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We subsequently analyzed their endoscopic and microscopic features and patient characteristics. The patients were 22 males and 12 females aged 57±23 years (mean±2SD). WLE showed raspberry-like small polyps mimicking gastric hyperplastic polyps in the oxyntic gastric compartment (body/fundus). Multiple growths were confirmed in 20.6% (7/34) of the patients. NBIME revealed irregularly shaped papillary/gyrus-like microstructures with abnormal capillaries. Histologically, all lesions were intraepithelial neoplasms, and most of lesions (62.8%, 27/43) exhibited low-grade dysplasia. Immunohistochemically, neoplastic cells featured strong and diffuse MUC5AC expression, negative or very low MUC6 expression, and negative MUC2/CD10 expression. They also showed Ki-67 hyperexpression with a mean labeling index of 59.4±48.7%. The coexistence of fundic gland polyps in the background mucosa was significantly higher in multiple FGA-RA cases than in solitary cases (100% vs. 55.5%, P< 0.05). FGA-RA is a newly suggested histologic variant of sporadic FGA whose occurrence is not rare in daily endoscopic practice.

Comparison of dapagliflozin and teneligliptin in nonalcoholic fatty liver disease patients without type 2 diabetes mellitus: a prospective randomized study.

There are no reports regarding the efficacy of sodium-glucose cotransporter 2 inhibitor (SGLT2i) and dipeptidyl peptidase 4 inhibitor (DPP4i) administrations in nonalcoholic fatty liver disease (NAFLD) patients without type 2 diabetes mellitus. The purpose of this study was to evaluate the efficacy of those drugs in such patients. NAFLD patients without type 2 diabetes mellitus were enrolled in this single center double-blind randomized prospective study, and allocated to receive either dapagliflozin (SGLT2i) or teneligliptin (DPP4i) for 12 weeks. Laboratory variables and body compositions were assessed at the baseline and end of treatment. The primary endpoint was alanine aminotransferase (ALT) reduction level at the end of treatment. Twenty-two eligible patients (dapagliflozin group, n = 12; teneligliptin group, n = 10) were analyzed. In both groups, the serum concentration of ALT was significantly decreased after treatment (p<0.05). Multiple regression analysis results showed that decreased body weight of patients with dapagliflozin administration was significantly related to changes in total body water and body fat mass. Administration of dapagliflozin or teneligliptin decreased the serum concentration of ALT in NAFLD patients without type 2 diabetes mellitus. With dapagliflozin, body weight decreased, which was related to changes in total body water and body fat mass (UMIN000027304).

Prevalence of functional dyspepsia-like symptoms in ulcerative colitis patients in clinical remission and overlap with irritable bowel syndrome-like symptoms.

Objective: Quiescent ulcerative colitis (UC) patients often have irritable bowel syndrome (IBS)-like symptoms and we recently showed that the prevalence of IBS-like symptoms in UC patients in clinical remission was significantly higher as compared to healthy control subjects. However, the prevalence of functional dyspepsia (FD)-like symptoms in quiescent UC patients remains unknown. The purpose of this study was to evaluate the prevalence of FD-like symptoms and the overlap with IBS-like symptoms in such patients.Materials and Methods: We reanalyzed the records of UC patients in remission using the subject cohort from our previous study. Clinical remission was defined as a clinical activity index (CAI) value ≤4 for at least 6 months. Diagnoses of FD- and IBS-like symptoms were evaluated by questionnaire according to the Rome III criteria.Results: One hundred seventy-two UC patients in clinical remission and 330 healthy control subjects were analyzed. Of the 172 patients, 9 (5.2%) met the criteria of FD, which was comparable with the controls (22/330, 6.7%). The prevalence rate of FD-like symptoms in UC patients with IBS-like symptoms (7/46, 15.2%) was lower as compared to that of the control subjects (6/16, 37.5%). On the other hand, a high percentage of the UC patients with FD-like symptoms also had IBS-like symptoms (7/9, 77.8%).Conclusions: Although the prevalence of FD-like symptoms in quiescent UC patients with IBS-like symptoms was low, UC patients with FD-like symptoms frequently had IBS-like symptoms.

Magnification endoscopy in combination with acetic acid enhancement and narrow-band imaging for the accurate diagnosis of colonic neoplasms.

Background and study aims Magnification endoscopy with narrow-band imaging (NBIME) and NBIME with acetic acid enhancement (A-NBIME) enable visualization of the vascular and microstructural patterns of colorectal polyp. We compared the diagnostic accuracy and reproducibility of white light endoscopy (WLE), NBIME, and A-NBIME for predictive histologic diagnosis. Patients and methods Consecutive colorectal polyps (N = 628; 38 hyperplasias, 488 adenomas, 72 M-SM1 cancers, and 30 SM2 cancers) were photographed with WLE, NBIME, and A-NBIME. Endoscopic images were independently reviewed by three experts, according to the traditional criteria for WLE, the Japan NBI Expert Team classification for NBIME, and pit pattern classification for A-NBIME to compare diagnostic accuracy and interobserver diagnostic agreement among modalities. Results The specificity (95 % confidence interval) of hyperplasia and SM2 cancer with WLE were 98.2 % (96.8 %-99.1%) and 99.4 % (98.5 %-99.9 %), respectively, showing high accuracy for endoscopic resection without magnifying observation. Diagnostic accuracy of WLE, NBIME, and A-NBIME was 80.8 % (77.4 %-83.8 %), 79.3 % (75.9 %-82.4 %), and 86.1 % (83.2 %-88.7 %), respectively, showing the highest accuracy for A-NBIME among modalities ( P  < .05). NBIME showed a lower PPV for M-SM1 cancer ( P  < .05), as with WLE ( P  = .08) compared to A-NBIME. Fleiss's kappa values for WLE, NBIME, and A-NBIME diagnosis were 0.43 (0.39 - 0.46), 0.52 (0.49 - 0.56) and 0.65 (0.62 - 0.69), respectively, showing insufficient reproducibility of WLE and superiority of A-NBIME among modalities. Conclusion WLE showed high accuracy for endoscopic resection of colorectal polyps in expert diagnosis. NBIME demonstrated a higher diagnostic reproducibility than WLE. A-NBIME showed possible superiority among modalities in both diagnostic accuracy and reproducibility.

Two Cases of Eosinophilic Gastroenteritis With Rare Manifestations Revealed in Medical Checkup Findings.

Eosinophilic gastroenteritis (EGE) is characterized by dense infiltration of eosinophils in gastrointestinal tissues, resulting in morphological and functional abnormalities of the gastrointestinal tract. EGE susceptibility is most common among individuals aged 40-50 years old, and hence it is likely that affected patients will be encountered at the time of a medical checkup. In this report, we present two rare cases of EGE that presented interesting manifestations in findings obtained in a fluoroscopic examination performed at an annual medical checkup. Accumulation of case reports is important to provide information to pathologists to enable them to make correct early diagnosis and begin effective treatment at the earliest.

Prospective multicenter study of the esophageal triamcinolone acetonide-filling method in patients with subcircumferential esophageal endoscopic submucosal dissection.

BACKGROUND AND AIM: The esophageal triamcinolone acetonide (TA)-filling method is a novel local approach for stenosis prevention after extensive esophageal endoscopic submucosal dissection (ESD). We evaluated this method after subcircumferential ESD. METHODS: We enrolled 20 patients with esophageal cancer requiring subcircumferential ESD in a prospective multicenter study. Esophageal TA filling was carried out 1 day and 1 week after ESD, with follow-up endoscopy every 2 weeks. We treated severe stenosis preventing endoscope passage with endoscopic balloon dilatation (EBD) and additional TA filling, and mild stenosis allowing endoscope passage with additional TA filling only. Primary endpoint was incidence of severe stenosis; secondary endpoints were total number of EBD, rate of additional TA filling, time to stenosis and complete re-epithelialization, dysphagia score, and adverse events. Horizontal resection grade was divided into grades 1 (≥ 9/12 and <10/12 of the circumference), 2 (≥ 10/12 and <11/12), and 3 (≥ 11/12 but not circumferential) and analyzed statistically for correlation with endpoints. RESULTS: Incidence of severe stenosis was 5.0% (1/20; 0.1-24.8%) and was treated with three EBD. Six patients showed mild stenosis. Additional TA filling was carried out in these seven patients: 0% (0/9) for grade 1 resection, 40% (2/5) for grade 2, and 83% (5/6) for grade 3 (P < 0.05). Median time to stenosis and re-epithelialization was 3 and 7 weeks, respectively. Dysphagia score deteriorated in one patient. No adverse events occurred. CONCLUSIONS: The esophageal TA-filling method prevented stenosis after subcircumferential ESD. Grade ≥2 resection showed a high risk for stenosis, but additional TA filling for mild stenosis inhibited stenosis progression (UMIN000024384).