Clinicopathological Features of Early Gastric Cancer Complicated by Autoimmune Gastritis.

INTRODUCTION: In the post-Helicobacter pylori era, autoimmune gastritis (AIG) is attracting increasing attention as an origin of gastric cancer. Here, we performed clinicopathological examination of gastric cancer complicating AIG treated in our hospital. METHODS: Eighty-six early gastric cancer lesions complicating AIG in 50 patients were treated by endoscopic submucosal dissection (ESD) at our hospital in 2008-2022. Their clinicopathological characteristics were compared with those of a control group comprising 2,978 early gastric cancer lesions (excluding lesions in the remnant stomach after surgery) in 2,278 patients treated by ESD during the same period. RESULTS: Mean age was significantly higher in the AIG group than in the control group (74.7 years vs. 70.9 years; p < 0.01). In the respective groups, the occurrence rate of synchronous/metachronous lesions was 38.0% and 20.4% (p < 0.01), the ratio of longitudinal cancer locations (upper/middle/lower third [U/M/L]) was 27/32/27 and 518/993/1,467 (p < 0.01), the ratio of circumferential cancer locations (lesser curvature/greater curvature/anterior wall/posterior wall) was 25/31/12/18 and 1,259/587/475/657 (p < 0.01), the ratio of major macroscopic types (I/IIa/IIb/IIc) was 13/38/5/30 and 65/881/220/1,812 (p < 0.01). The rates of multiple gastric cancer and cancers in the U region, at the greater curvature, and of protruding types were significantly higher in the AIG group. CONCLUSION: The occurrence rate of multiple gastric cancer was significantly higher in gastric cancer complicating AIG (approximately 40%), and compared with the control group, the proportions of cancers at the U region, at the greater curvature, and of protruding types were significantly higher.

Multicenter retrospective analysis of complications and risk factors in endoscopic resection for esophageal cancer across Japan.

BACKGROUND: Endoscopic resection (ER) is a minimally invasive treatment for esophageal cancer that sometimes causes complications. To understand the real-world incidence and risk factors for these complications, a nationwide survey was conducted across Japan. METHODS: This retrospective multicenter study included patients who underwent ER for esophageal cancer from April 2017 to March 2018 (2017 complication analysis) and April 2021 to March 2022 (2021 complication analysis). The study assessed the complication rates and conducted risk factor analyses for endoscopic submucosal dissection (ESD) using data for these patients, with exclusions based on specific criteria to ensure data accuracy. RESULTS: In the 2021 complication analysis, there were two mortalities highly likely attributable (0.03%) to ER and one mortality possibly attributable (0.01%) to ER. Intraoperative perforation, delayed bleeding, and pneumonia occurred in 137 cases (1.8%), 44 cases (0.6%), and 130 cases (1.7%), respectively. In the multivariate analysis for complications after ESD, low ER volume of the facility was an independent risk factor for perforation, while lesion location in the cervical or upper thoracic esophagus was an independent factor for reduced risk of perforation. Age ≥ 80 years was a risk factor for pneumonia, while use of traction techniques was a factor for reduced risk of pneumonia. Lesions located in the middle thoracic esophagus had a lower risk of stricture, and the risk of stricture increased as the circumferential extent of the lesion increased. CONCLUSIONS: This large-scale study provided detailed insights into the complications associated with esophageal ER and identified significant risk factors.

Long-term outcome of cervical lymph node metastasis in superficial pharyngeal squamous cell carcinoma after endoscopic submucosal dissection.

BACKGROUND AND AIMS: Superficial pharyngeal squamous cell carcinoma (PSCC) has received increasing attention as a therapeutic target in the GI field with recent innovations in endoscopic submucosal dissection (ESD). However, there are currently no defined criteria for the application of ESD to superficial PSCC. One of the problems encountered during follow-up after ESD is cervical lymph node metastasis (LNM). Identifying the clinicopathologic predictors of cervical LNM can help to provide a basis for the refinement of therapeutic strategies for superficial PSCC. METHODS: The risk of cervical LNM was evaluated in 331 patients with superficial PSCC who underwent initial ESD between 2008 and 2021. Since tumor size, rather than depth, is the dominant factor in the current TNM classification for PSCC, the correlation between tumor size and thickness was investigated. RESULTS: The median follow-up period was 4.8 years. The cumulative 5-year cervical LNM rate was 6.1%. Multivariate Cox proportional hazards regression analysis identified tumor thickness ≥1000 µm and lymphatic invasion as significant independent predictors. Among 204 cases with subepithelial invasion, both factors were also revealed to be significant independent predictors, suggesting that tumor thickness was superior to tumor size in predicting cervical LNM. Despite the positive correlation between tumor thickness and size, there was noticeable variability in the values (R = .20), and the current staging was inadequate to identify groups at high risk for cervical LNM. CONCLUSIONS: Tumor thickness and lymphatic invasion are validated as significant independent predictors for cervical LNM and can be useful indicators to optimize the therapeutic strategies for superficial PSCC.

Long-Term Outcomes of Endoscopic Submucosal Dissection for Special Type of Esophageal Cancer.

BACKGROUND: Esophageal cancers other than two types, squamous cell carcinoma (SCC) and adenocarcinoma, are commonly referred to as special type of esophageal cancer (STEC). Studies on STECs have been limited because of its low prevalence. Therefore, we aimed to clarify the clinicopathological findings and the long-term outcomes of STECs that were managed with ESD. METHODS: We reviewed 713 patients with 1,089 lesions who underwent ESD for primary esophageal cancer except Barrett's esophageal cancer. Patients were classified into the SCC group and the STEC group, respectively. Their clinicopathological findings and long-term outcomes including disease-specific survival (DSS) were collected and examined. RESULTS: A total of 19 consecutive patients (1.7%) were diagnosed with STEC. Nine patients were diagnosed with basaloid carcinoma, 6 with adenosquamous carcinoma, 2 with mucoepidermoid carcinoma, 2 with salivary duct-type carcinoma, and 1 with neuroendocrine cell carcinoma. There was significantly more pT1b esophageal cancer (47.4% vs. 11.0%, p < 0.01) and lymphovascular invasion (31.6% vs. 10.2%, p = 0.011) in the STEC group. Metastatic relapse and disease-specific mortality were significantly higher in the STEC group (both 15.8% vs. 1.2%, p < 0.01), and the STEC group had shorter DSS with 5-year DSS rates of 90.9%. In a subgroup analysis of patients with pT1a esophageal cancer, the 5-year DSS rate was shorter in the STEC group (p < 0.01). In the multivariate analysis, STEC (HR = 0.24) and tumor depth (HR = 12.60) were the factors associated with DSS. CONCLUSION: STECs are suggested to have high malignant potential and to be an independent negative prognostic factor for DSS.

Safety of Cold Snare Polypectomy during Continuous Use of Antithrombotic Drugs for Delayed Post-Polypectomy Bleeding: A Pilot Study.

BACKGROUND: Cold snare polypectomy is a high-risk endoscopic procedure with a low delayed post-polypectomy bleeding rate. However, it is unclear whether delayed post-polypectomy bleeding rates increase during continuous antithrombotic treatment. This study aimed to determine the safety of cold snare polypectomy during continuous antithrombotic treatment. METHODS: This single-center, retrospective cohort study enrolled patients who underwent cold snare polypectomy during antithrombotic treatment between January 2015 and December 2021. Patients were divided into continuation and withdrawal groups based on whether they continued with antithrombotic drugs or not. Propensity score matching was performed using age, sex, Charlson comorbidity index, hospitalization, scheduled treatment, type of antithrombotic drugs used, multiple medications used, indication for antithrombotic drugs, and gastrointestinal endoscopist qualifications. The delayed polypectomy bleeding rates were compared between the groups. Delayed polypectomy bleeding was defined as the presence of blood in stools and requiring endoscopic treatment or a decrease in hemoglobin level by 2 g/dL or more. RESULTS: The continuation and withdrawal groups included 134 and 294 patients, respectively. Delayed polypectomy bleeding was observed in 2 patients (1.5%) and 1 patient (0.3%) in the continuation and withdrawal groups, respectively (p = 0.23), before propensity score matching, with no significant difference. After propensity score matching, delayed polypectomy bleeding was observed in 1 patient (0.9%) in the continuation group but not in the withdrawal group, with no significant difference. CONCLUSION: Cold snare polypectomy during continuous antithrombotic treatment did not significantly increase delayed post-polypectomy bleeding rates. Therefore, this procedure may be safe during continuous antithrombotic treatment.

Metachronous Multiple Gastric Cancer Discovered as Endoscopic Curability C2 during Regular Follow-Up after Gastric Endoscopic Submucosal Dissection.

INTRODUCTION: The objective of this study was to clarify characteristics of metachronous endoscopic curability C2 (eCura C2) cancer during post-endoscopic submucosal dissection (ESD) follow-up. METHODS: Of 4,355 gastric lesions treated by ESD at our hospital during 2005-2021, 657 were metachronous. After excluding lesions found ≥2 years since the prior examination or in the gastric remnant, the remaining 515 were analyzed. Study 1: We compared 35 eCura C2 cancers and 480 eCura A-C1 cancers. Study 2: Endoscopic findings of the 35 lesions were examined to determine why they had been missed. RESULTS: Mean tumor size was larger (34.0 mm vs. 12.1 mm, p < 0.01) and the proportions of mixed-type and poorly differentiated cancers were higher (highly:mixed:poorly, 34.3:57.1:8.6 vs. 94.2:5.0:0.8, p < 0.01) in the eCura C2 group. Study 2: At the prior examination, 4 lesions were noticed but considered benign, 2 lacked sufficient imaging, 19 were detectable on imaging but missed, and 10 were not detectable on imaging. Over half the lesions that were detectable but missed at the prior examination were in the lesser curvature, many being type IIa-IIb lesions with color similar to the background mucosa. All lesions not detectable on imaging at the prior examination were mixed-type or poorly differentiated type. DISCUSSION: Metachronous cancer detected as eCura C2 cancers was significantly larger, and a significantly higher proportion was mixed-type or poorly differentiated cancers, compared with eCura A-C1 cancers. Possible reasons why these lesions were missed include rapid progression of mixed-type and poorly differentiated cancers, and poor recognition that lesions showing only slight color changes may be present at the lesser curvature.

Diagnostic Performance of Endoscopic Ultrasonography with Water-Filled Balloon Method for Superficial Esophageal Squamous Cell Carcinoma.

BACKGROUND: Endoscopic ultrasonography (EUS) is a commonly used tool for preoperative depth diagnosis of superficial esophageal squamous cell carcinoma (ESCC). Probing EUS using the water-filled balloon method is a simple and safe examination. AIM: The aim of this study was to clarify the diagnostic performance of EUS with the water-filled balloon method for superficial ESCC compared to magnifying narrow-band imaging (ME-NBI). METHODS: We retrospectively examined 403 lesions in 393 consecutive patients diagnosed with ESCC and evaluated them with ME-NBI and EUS. Clinicopathological findings were collected, and the accuracy of the preoperative diagnosis was compared between ME-NBI and EUS-B. EUS examiners were not blinded to prior ME-NBI results, and EUS results may have been influenced by ME-NBI results. RESULTS: The pathological tumor depth of the EP/LPM in 152 lesions, MM/SM1 in 130 lesions, and deep submucosa (SM2/SM3) in 121 lesions was examined. The proportion of total lesions with an accurate diagnosis was significantly higher in EUS than in ME-NBI (67.7% versus 62.0%, P = 0.015). When analyzed by clinical depth diagnosis using ME-NBI, the proportion of lesions with an accurate diagnosis was significantly higher for EUS in MM/SM1 (55.7% versus 46.1%, P = 0.033). The sensitivity was significantly higher in EUS for SM2/SM3 lesions (76.0% versus 54.5%, P < 0.001). The accuracy and specificity of EUS, which differentiate MM/SM1 from EP/LPM or SM2/SM3, were significantly higher than those of ME-NBI. The median endoscopic ultrasonography procedure time was approximately 6.5 min. CONCLUSIONS: EUS with the water-filled balloon method is a safe and straightforward method that can be performed on lesions clinically diagnosed as MM/SM1 using ME-NBI. We retrospectively reviewed lesions in patients diagnosed with ESCC and evaluated them using magnifying endoscopy with narrow-band imaging (ME-NBI) and endoscopic ultrasound using the water-filled balloon method (EUS-B). We conclude that EUS-B can increase the diagnostic accuracy.

Clinical predictors of special type of esophageal cancer.

BACKGROUND: Esophageal cancers with a histological type other than the two major types, squamous cell carcinoma (SCC) and adenocarcinoma, are referred to as "special type of esophageal cancer" (STEC). STEC is rare and difficult to diagnose preoperatively. Therefore, we aimed to clarify the clinicopathological findings of STEC, including magnifying endoscopy with narrow band imaging (ME-NBI). METHODS: We reviewed 1133 lesions in 936 consecutive cases who underwent endoscopic resection or surgical resection for primary esophageal cancer. Patients were classified into the SCC group and the STEC group, respectively. Factors that predict STEC endoscopically, as well as clinicopathologic features of STEC compared to SCC, were examined. RESULTS: Twenty-eight STECs were diagnosed in 28 patients: 15 with basaloid squamous cell carcinoma, 6 with adenosquamous carcinoma, 4 with mucoepidermoid carcinoma, 1 with carcinosarcoma, 1 with salivary duct-type carcinoma, and 1 with neuroendocrine cell carcinoma. There was significantly more pT1b or deeper cancer (60.7% vs. 12.8%), lymphovascular invasion (50.0% vs. 11.1%) and elevated type (53.6% vs. 16.1%) in the STEC group. The proportion of lesions with type R vessels on ME-NBI was significantly higher in the STEC group (46.4% vs. 3.9%). The STEC group had significantly lower accuracy of ME-NBI for prediction of depth (64.3% vs. 83.5%) and a greater proportion of underestimated lesions (32.1% vs. 9.3%). In the multivariate analysis, the histopathology of STEC was associated with type R vessels on ME-NBI. CONCLUSION: Type R vessels and submucosal tumor-like elevation might be the clinical predictors of STEC.

Effect of Helicobacter pylori infection on malignancy of undifferentiated-type gastric cancer.

BACKGROUND: Although almost all cases of gastric cancer are caused by Helicobacter pylori (HP) infection, there are some rare exceptions. Furthermore, the clinicopathological characteristics of gastric cancer may differ depending on HP infection status. This study aimed to determine the clinicopathological characteristics of undifferentiated-type gastric cancer (UD-GC) according to HP status. METHODS: The study involved 83 patients with UD-GC who were selected from 1559 patients with gastric cancer who underwent endoscopic resection at our hospital and whose HP infection status was confirmed. Clinicopathological characteristics were evaluated according to HP status (eradicated, n = 28; infected, n = 32; not infected, n = 23). RESULTS: In patients without HP infection, UD-GCs were < 20 mm and intramucosal with no vascular invasion. In patients with eradicated HP, there was no correlation between development of UD-GC and time since eradication. Nine of twelve patients with a tumor detected ≥ 5 years after eradication had undergone yearly endoscopy. Submucosal invasion was observed in two of four patients and lymphovascular invasion in three of four patients whose UD-GC was detected ≥ 10 years after eradication. There was no significant between-group difference in the frequency of lesions with invasion into the submucosal layer or deeper (14.3%, 10.5%, and 0% in the UD-E, UD-I, and UD-U groups, respectively). CONCLUSION: The clinicopathological characteristics of UD-GC were similar between HP-infected patients and HP-eradicated patients. Three of four patients with eradicated HP whose UD-GC developed ≥ 10 years after eradication were not eligible for endoscopic treatment and required additional surgery resection. In contrast, UD-GC was curable by endoscopic resection in all patients without HP infection.

Comprehensive risk evaluation for metachronous carcinogenesis after endoscopic submucosal dissection of superficial pharyngeal squamous cell carcinoma.

BACKGROUND: Pharyngeal squamous cell carcinoma (PSCC) is associated with a high likelihood of metachronous carcinogenesis, which is known to have a poor prognosis. This study aimed to identify comprehensive risk evaluation indicators for metachronous carcinogenesis after endoscopic submucosal dissection (ESD) of superficial PSCC. METHODS: The risk of metachronous carcinogenesis was evaluated in 144 patients with superficial PSCC (with no history of PSCC or esophageal squamous cell carcinoma) who underwent initial ESD from 2008 to 2020. Multiple lugol-voiding lesions (LVLs) in the background pharyngeal and esophageal epithelium were evaluated as endoscopic indicators. The hemoglobin, albumin, lymphocyte, and platelet (HALP) score was analyzed as a serum marker. RESULTS: The median follow-up period was 4.3 years. The coincidence rate for pharyngeal and esophageal LVL grade was 55%. The cumulative 3-year metachronous PSCC rate was 18.9%. The cumulative 3-year second metachronous PSCC rate was 43.9%. Forward stepwise multivariate Cox proportional hazards regression analysis identified pharyngeal LVL grade and a lower HALP score as significant independent predictors. Pharyngeal LVL grade was superior to esophageal LVL grade as a predictor of metachronous PSCC. A lower HALP score was significantly associated with younger age in forward stepwise multivariate logistic regression analysis. CONCLUSIONS: Patients with a history of superficial PSCC remain at risk for metachronous carcinogenesis over time, and long-term follow-up is imperative. Comprehensive evaluation of endoscopic features with a novel serum marker, namely, the HALP score, can help predict metachronous carcinogenesis.

Clinical relevance of endoscopic treatment for superficial pharyngeal cancer: feasibility of techniques corresponding to each location and long-term outcomes.

BACKGROUND AND AIMS: Superficial pharyngeal cancers are being detected and treated using endoscopy in many medical facilities with increasing frequency. However, the reports focus on the hypopharynx. We identified reliable treatments by adapting the method for each region of the pharynx. Here, we introduce our methods for treating various pharyngeal regions and show their long-term results. METHODS: Of 308 consecutive patients who underwent pharyngeal endoscopic submucosal dissection between February 2007 and December 2018 at our institution, we selected 293 patients who were diagnosed histologically with squamous cell carcinoma. The patients were divided into 4 groups based on the specific location of superficial pharyngeal lesions and the short- and long-term outcomes, such as technical success, adverse events, overall survival, and case-specific survival, were evaluated. RESULTS: The procedure time was 51 minutes at location A where cancer develops most commonly. The rate of en bloc resection was 99.4%, and the R0 resection rate was 82.6%. With regard to adverse events, there were 2 cases of postoperative hemorrhage, both treated with endoscopic hemostasis. The average observation period was 61.2 months overall, with 14 cases of recurrent lymph node metastasis. The 5-year survival rate was 84.1%, and cause-specific survival was 100%. CONCLUSIONS: Adaptation of the treatment method according to the location of the lesion led to good results. Endoscopic treatment of superficial pharyngeal cancer is both feasible and beneficial.

Efficacy of Vonoprazan for Refractory Reflux Esophagitis after Esophagectomy.

BACKGROUND: Refractory reflux esophagitis (RRE), unresponsive to conventional proton-pump inhibitors (PPIs), is a complication in esophagectomy with gastric pull-up. Vonoprazan (VPZ), a novel potassium-competitive acid blocker, has been available in Japan since 2015. Here, we investigated the efficacy of VPZ on PPI-resistant RRE after esophagectomy with gastric pull-up. METHODS: This was a single-center retrospective study. We used the revised Los Angeles (r-LA) classification based on the Los Angeles classification and the modified Los Angeles classification to evaluate abnormal forms of mucosal breaks such as lateral spreading consistently. Patients who underwent esophagectomy with gastric pull-up and had RRE grade B-D as per the r-LA classification, despite using standard-dose PPIs or double dose of rabeprazole, were included. Sixteen patients who switched to VPZ (20 mg/day) and 14 patients who continued PPIs were assigned to the VPZ and PPI groups, respectively. Endoscopic observations were reviewed by 3 endoscopists using the r-LA classification to ensure consistent diagnosis, while the treatment arm and patient information were blinded to evaluators. We defined mucosal breaks that improved by at least one grade after treatment as improved mucosa and recovery to grade M or N as mucosal healing. RESULTS: The percentage of patients with improved mucosa in the VPZ and PPI groups was 81.3 and 14.3%, respectively (p < 0.001). The rate of mucosal healing was 68.8 and 7.1%, respectively (p = 0.001). CONCLUSION: VPZ significantly improved PPI-resistant RRE after esophagectomy with gastric pull-up.

Effectiveness of Chemoradiotherapy for Metachronous Esophageal Squamous Cell Carcinoma.

INTRODUCTION: Multiple Lugol-voiding lesions (LVLs) in the esophagus increase the risk of synchronous and metachronous development of esophageal squamous cell carcinoma (ESCC). Chemoradiotherapy (CRT) following endoscopic submucosal dissection (ESD) may reduce the incidence of metachronous ESCC, but few studies have investigated this. Therefore, we retrospectively examined the effect of CRT on metachronous ESCC and multiple esophageal dysplasias visible as multiple LVLs. METHODS: This study reviewed 146 patients who underwent esophageal ESD and were determined pathologically to have noncurative resection. They were divided into 2 groups: those who received additional CRT (CRT group; n = 64) and those without additional treatment (control group; n = 82). Incidence of metachronous ESCC was analyzed using propensity scores to adjust for patient characteristics. The number of multiple LVLs was also examined. RESULTS: The CRT group was significantly younger than the control group (mean 66.6 vs. 70.6 years, p = 0.011), had significantly deeper tumor invasion (p = 0.013), and had a significantly higher rate of lymphovascular invasion (47.8 vs. 12.2%, p < 0.001). The CRT group also had a significantly higher improvement rate of multiple LVLs (58.1 vs. 2.0%, p < 0.001). The LVLs after CRT had a distinctive irregular crack-shaped appearance. Metachronous ESCC was found in 7 patients (10.9%) in the CRT group and in 17 patients (20.7%) in the control group (p = 0.113). In propensity score-adjusted logistic regression analysis, the odds ratio for metachronous ESCC in the CRT group was 0.316 (p = 0.023). The occurrence rate was significantly lower in the CRT group than in the control group. DISCUSSION/CONCLUSION: CRT may be effective in preventing metachronous ESCC.

Metachronous carcinogenesis of superficial esophagus squamous cell carcinoma after endoscopic submucosal dissection: incidence and risk stratification during long-term observation.

BACKGROUND: This study aimed to reveal long-term outcomes, such as incidence of metachronous esophageal and head and neck squamous cell carcinomas and overall survival rate, through long-term observation of patients with esophageal carcinoma post-endoscopic submucosal dissection. METHODS: Risk of metachronous carcinogenesis was evaluated in 88 patients with intramucosal esophageal carcinoma (without history of metachronous esophageal or head and neck squamous cell carcinomas) who underwent endoscopic submucosal dissection from 2007 to 2008 and were endoscopically observed for > 3 years. Histologically, the papillary vessel is defined as the clock gear-like structure composed of capillaries directly penetrating the epithelium (starting from the lamina propria) and covering at least two-thirds of it, around which the tumor cells are arranged in a spiral pattern. RESULTS: Median endoscopic follow-up period was 11.0 years. Cumulative 2-, 5-, and 10-year metachronous esophageal carcinoma rates were 11.4%, 20.6%, and 39.3%, respectively. Stepwise multivariate Cox proportional hazard regression analysis identified multiple Lugol-voiding lesions (LVLs) as the single significant independent predictor. Cumulative 2-, 5-, and 10-year metachronous head and neck squamous cell carcinoma rates were 6.9%, 10.4%, and 19.6%, respectively. Stepwise multivariate Cox proportional hazard regression analysis identified multiple LVLs, Brinkman index, papillary vessel, and younger age as significant predictive factors. Overall post-endoscopic submucosal dissection survival rates were 98.8% and 87.5% at 5 and 10 years, respectively. CONCLUSION: Patients with a history of esophageal carcinoma remain at risk for metachronous carcinogenesis even > 5 years after endoscopic submucosal dissection. Thus, long-term follow-up is important.

Primary alveolar soft part sarcoma of the rectum resected by endoscopic submucosal dissection: A case report.

Alveolar soft part sarcoma (ASPS) is a very rare soft tissue sarcoma. Primary ASPS of the gastrointestinal tract is especially rare. Due to the scarcity of cases, neither its clinicopathologic features nor its mutational background has been clarified. Here, we report a case of ASPS arising from the rectum, which was completely resected by endoscopic submucosal dissection. The lesion was a 17 × 16 × 15 mm semi-pedunculated mass in the upper portion of the rectum in a 46-year-old female. In terms of histology, tumor cells exhibited confluent eosinophilic cytoplasm, forming a sheet-like architecture. Periodic acid Schiff-positive diastase-resistant intracytoplasmic crystals were observed in the tumor cells. Fluorescence in situ hybridization revealed TFE3 rearrangement, and reverse transcription polymerase chain reaction revealed an ASPSCR1-TFE3 type 1 fusion. Negative PAX8 immunostaining and the absence of other massive lesions in postoperative imaging studies led to a diagnosis of primary ASPS of the rectum. The potential oncogenic role of the canonical ASPSCR1-TFE3 fusion transcript in gastrointestinal ASPS was indicated. Primary gastrointestinal ASPS remains a diagnostic pitfall in routine surgical pathology.

Columnar epithelium morphology after esophagectomy: clinical insight into the development of Barrett's esophagus.

BACKGROUND: The presence of Barrett's mucosa in the esophageal remnant is a result of post-esophagectomy anastomotic site exposure to gastric acid and is regarded as a human model of Barrett's esophagus onset. Here, we attempted to clarify the relationship between duodenogastric reflux and formation of columnar epithelium by following the changes over time after esophagectomy. METHODS: A total of 96 patients underwent esophagectomy due to superficial cancer from April 2000 to March 2018 were included in this study. Cases were divided into two groups according to the reconstruction technique after esophagectomy as either the gastric pull-up (Ga) group and ileocolonic interposition (Ic) group. Previously obtained endoscopic pictures of the cases were reviewed retrospectively and chronologically. RESULTS: There were 24 cases of columnar epithelium in the Ga group (42%) and 1 in the Ic group (2.6%) (P < 0.01) with 32 reflux cases (56%) in the Ga group and 1 (2.6%) in the Ic group (P < 0.01). Reflux precedes the development of columnar epithelium in both the Ga- and Ic groups. Multivariate analysis revealed surgical technique (odds ratio 10.6, 95% CI 1.2-97.5, P = 0.037) and reflux (odds ratio 4.5, 95% CI 1.3-15.6, P = 0.0017) as risk factors. CONCLUSIONS: The development of columnar epithelium was preceded by reflux comprising principally gastric acid and was strongly associated with a strong inflammatory state.

Utility of Valsalva maneuver in the endoscopic pharyngeal observation.

BACKGROUND: Metachronous cancer rate in the pharynx is high before and after the treatment of esophageal cancer. Endoscopic observation is difficult in the pharynx especially in the postcricoid area. Pharyngeal cancer in the postcricoid area has been often found in advanced stage. Valsalva maneuver has been reported to improve the visibility. METHODS: From May 2017 we introduced a dedicated mouthpiece to conduct Valsalva maneuver. One hundred consecutive patients who had been observed throughout the pharynx by one endoscopist were enrolled. A total of 200 image files before and after introduction were made and reviewed by three endoscopists. We retrospectively evaluated the utility and safety of Valsalva maneuver. RESULTS: The visibility before introduction was Good in three cases, Moderate in 12 cases and Poor in 85 cases. Meanwhile, the visibility after introduction was Good in 58 cases, Moderate in 23 cases, and Poor in 19 cases (P < 0.05). Nine lesions including hypopharyngeal cancer were found and adverse events were not observed in this study. CONCLUSION: The Valsalva maneuver was considered to be a safe and effective method in endoscopic observation of the pharynx.

Comparison of 3D endoscopy and conventional 2D endoscopy in gastric endoscopic submucosal dissection: an ex vivo animal study.

BACKGROUND AND OBJECTIVES: Conventional endoscopy provides two-dimensional (2D) information without depth information. This study compared three-dimensional (3D) endoscopy and 2D endoscopy using an endoscopic submucosal dissection (ESD) training model to evaluate the utility of 3D endoscopy. METHODS: Porcine stomach specimens (7 × 7 cm) were prepared from commercially available resected porcine stomachs and a 10-mm hypothetical lesion was marked at the center of each specimen. Specimens were individually placed in an ESD training model, and subjected to either 2D or 3D ESD. En bloc resection rate, perforation rate, incision time, dissection time, and levels of five eyestrain symptoms (fatigue, pain, blurred vision, head-heaviness, and headache; 100-mm visual analog scale) were compared between the 2D and 3D procedures. In a crossover design, 8 endoscopists each performed two 2D and two 3D procedures. RESULTS: All 32 lesions were resected en block, but perforation occurred in one 2D procedure. Incision time was significantly shorter in 3D ESD than in 2D ESD (102.8 ± 42.1 s vs. 135.8 ± 65.7 s, p < 0.05). Dissection time was also significantly shorter in 3D ESD than in 2D ESD (366.3 ± 187.6 s vs. 517.8 ± 282.3 s, p < 0.05). Differences in levels of all symptoms except blurred vision between before and after ESD were larger in 3D ESD than in 2D ESD. CONCLUSIONS: Incision time and dissection time were significantly shorter in 3D ESD compared with 2D ESD, but eyestrain was increased. Depth information from 3D images appears to facilitate rapid and stable ESD maneuvers.

Operational effectiveness of three-dimensional flexible endoscopy: an ex vivo study using a new model.

BACKGROUND AND OBJECTIVES: Two-dimensional (2D) images lack depth information and thus provide probabilistic recognition that do not completely match the actual three-dimensional (3D) information. Here, we investigated the operability of 3D endoscopes. METHODS: A 3D operation model was developed by passing 20 silk threads through upper and lower plates at 2-mm intervals in front and back rows separated by 1 mm. We evaluated accuracy and time of operating an electrosurgical knife. A successful operation was defined as pulling only a front-row thread; an unsuccessful operation was defined as pulling no thread (miss) or simultaneously pulling front- and back-row threads. Endoscopists (four experts, six trainees) repeated the operation under 2D and 3D conditions until individually accumulating 10 successful attempts under each condition. RESULTS: Operation accuracy was significantly higher for 3D compared with 2D in all endoscopists (88.5% vs. 61.3%; p < 0.01) and in both experience groups (trainees: 84.5% vs. 61.2%; experts: 95.2% vs. 61.5%; both p < 0.01). Operation time was significantly shorter for 3D compared with 2D in all endoscopists (12.5 ± 4.1 s vs. 14.8 ± 4.7 s; p < 0.01) and in both experience groups (trainees: 12.8 ± 4.2 s vs. 15.2 ± 4.9 s; experts: 12.1 ± 4.0 s vs. 14.3 ± 4.3 s; both p < 0.01). DISCUSSION: Compared with 2D endoscopy, 3D endoscopy significantly improved operation accuracy and shortened operation time, suggesting that 3D endoscopy enables accurate operation by depth information, aiding spatial recognition.