Endoscopic mucosal resection: not only therapeutic, but a diagnostic procedure for sessile gastric polyps

The long-term outcome and risk factors of histologic discrepancy between forceps biopsies and endoscopic resections in early gastric cancer: An observational study

Although endoscopic forceps biopsy is the gold standard for early gastric cancer (EGC) diagnosis, the method can cause endoscopic resection of specimens and histological discrepancies. This study aims to examine the risk factors for histological discrepancies in EGC and long-term clinical outcomes. This retrospective study included patients diagnosed with differentiated-type EGC using forceps biopsy. Patients without histological discrepancies and with undifferentiated types in endoscopic resection histology were categorized into the concordant and discordant groups, respectively. Clinical characteristics and long-term outcomes related to histological discrepancies were analyzed. A total of 957 lesions from 936 patients were enrolled. An overall discrepancy rate of 8.7% was confirmed, with an undifferentiated-type discrepancy of 5.5%. The discordant group showed a higher tendency for lesions to be located in the upper third region, to have whitish discoloration, and to undergo a greater number of biopsies compared with the concordant group. Multivariate analysis confirmed that lesion location in the upper third region (odds ratio [OR]: 2.125; 95% confidence interval [CI]: 1.032-5.277; P = .041) and whitish surface discoloration (OR: 13.615; 95% CI: 6.028-28.728; P = .001) were significantly correlated with histologic discrepancy. Compared with the concordant group, the discordant group had a lower curative resection rate, but no differences were observed in complications, local recurrence, or survival rates. Upper third location and whitish discoloration were risk factors for the histologic discrepancy between differentiated and undifferentiated types in patients with EGC. For curative resections performed in patients with EGC and histologic discrepancies and without additional treatment, careful follow-up is possible.

Comparative analysis of differences between preoperative endoscopic biopsy and postoperative pathological examination for diagnosis of gastric intraepithelial neoplasia

OBJECTIVE

This study was performed to compare the differences between preoperative endoscopic biopsy (PEB) and postoperative pathological examination (PPE) for diagnosis of gastric intraepithelial neoplasia (GIN).

METHODS

From September 2016 to July 2019, 188 consecutive patients with GIN at Yuyao People's Hospital were retrospectively analyzed. The 188 patients had 218 GIN lesions. All patients underwent PEB and either endoscopic submucosal dissection or surgical treatment. PPE was performed on pathological tissues that had been surgically removed.

RESULTS

Among 138 cases of low-grade dysplasia (LGD) diagnosed by PEB, 46 were upgraded to high-grade dysplasia (HGD), 20 were upgraded to early gastric cancer (EGC), and 2 were downgraded to inflammation after PPE. Among 42 cases of HGD, 23 were upgraded to EGC, 2 were downgraded to LGD, and 2 were downgraded to inflammation after PPE. Among 38 cases of EGC, 1 was downgraded to HGD and 2 were downgraded to LGD after PPE. The original diagnosis was maintained after the operation in 120 cases of GIN.

CONCLUSION

Biopsy did not fully reflect the lesions of GIN. Biopsy review should be actively performed, and the lesions should be clarified by endoscopic submucosal dissection or surgery.

Diagnosis and Endoscopic Treatment of Gastrointestinal Stromal Tumors Arising from Esophagus

Aim: The primary purpose of this study was to investigate the diagnosis and endoscopic treatment of gastrointestinal stromal tumors (GISTs) arising from esophagus. Materials and Methods: From January 2013 to December 2017, 16 cases of GISTs of esophagus were retrospectively identified from a total of >3000 GISTs treated in our center. Demographic characteristics, clinical data, endoscopic therapy outcomes, histopathology, and follow-up were analyzed. Results: The mean age of the patients was 53 years (range 35-71 years), mostly female (56.3%). Seven tumors were in the lower esophagus, five in the middle esophagus, and one in the upper esophagus. The most common symptom was abdominal discomfort (8/16; 50.0%), followed by acid reflux (6/16; 37.5%). All of the patients underwent CT scan, gastroscopy, and/or endoscopic ultrasound. Two patients were diagnosed with esophageal GISTs with a preoperative endoscopic biopsy. Tumors were resected completely in all patients by endoscopic surgery. The median operating time was 85 minutes (range 28-153 minutes), and the average tumor size was 11.6 mm (range 6-21 mm). Postoperative histopathology demonstrated esophageal GISTs were positive for CD117 and CD34. The mean length of postoperative hospital stay was 4.7 days (range 2-7 days). The median postoperative follow-up duration was 28 months (range 1-59 months). Conclusion: Endoscopic treatment seems to be safe and effective for tumors size <20 mm in diameter. However, long-term prospective randomized controlled trials are further needed.

Introduction of endoscopic submucosal dissection in the West

Endoscopic submucosal dissection (ESD) is well established in Asia as a modality for selected advanced lesions of both the upper and lower gastrointestinal tract, but ESD has not attained the same niche in the West due to a variety of reasons. These include competition from traditional surgery, minimally invasive surgery and endoscopic mucosal resection. Other obstacles to ESD introduction in the West include time commitment for learning and doing procedures, a steep learning curve, special equipment, lack of mentors, cost issues, interdisciplinary conflicts, concern regarding complications and lack of support from institutions and interfacing departments. There are intrinsic differences in pathology prevalence (e.g., early gastric cancer) between the two regions that are less conducive for ESD implementation in the West. We will elaborate on these issues and suggest measures as well as a protocol to overcome these obstacles and hopefully allow introduction of ESD as a tenable option for appropriate patients.

What Is Most Important to the Endoscopist for Therapeutic Plan? Morphology versus Pathology: A Nationwide Multicenter Retrospective Study in Korea

Histologic discrepancy may sometimes occur between biopsy and endoscopic resection. We investigated the discrepancy rate between the biopsy and the resection lesion in the Korean population. From January 2010 to October 2016, 268 patients with gastric endoscopic mucosal resection/endoscopic submucosal dissection history from nationwide hospitals were enrolled retrospectively. We compared the histologic discrepancy rates from the biopsy and the resection. The mean age was 63.2 years. Gastric adenomas occurred most frequently in the antrum. The pathology of the resected specimens classified 25 lesions (9.3%) as gastritis/hyperplasia, 146 lesions (54.5%) as low-grade dysplasia, 76 lesions (28.4%) as high-grade dysplasia (HGD), and 21 lesions (7.8%) as adenocarcinoma. The discrepancy rate between biopsy and resection was 23.1 per cent. Among the 44 cases of gastritis/hyperplasia, two cases (4.5%) were diagnosed as HGD and 11 cases (25.0%) were diagnosed as cancer after resection. Among the 182 cases of low-grade dysplasia, 33 cases (18.1%) were diagnosed as HGD and nine cases (5.0%) were diagnosed as cancer after resection. Gastritis/hyperplasia, ulceration, and lesions in the lower body location were significant factors related to the discrepancies. Especially, discrepancy occurred most frequently in gastritis/hyperplasia lesions with ulcer in the lower body. There was considerable histologic discrepancy between biopsy and resection. Ulcerative-type tumor morphology and biopsy diagnosis of gastritis/hyperplasia are suggestive factors predictive of discrepancy between biopsy and resection in terms of malignancy. Therefore, although the results of biopsy are gastritis/ hyperplasia, suspicious tumorous lesions with ulcer should be indicative of active endoscopic resection for diagnosis and treatment.

The Diagnostic Accuracy of Conventional Forceps Biopsy Compared to ESD

Objective

conventional forceps biopsy (CFB) is the most popular way to screen for gastric epithelial neoplasia (GEN). Our study aimed to compare the diagnostic accuracy between conventional forceps biopsy and endoscopic submucosal dissection (ESD).

Methods

105 patients diagnosed GEN finally undertook ESD in our hospital were enrolled. We retrospectively assessed the characteristics of pathological results of CFB and ESD.

Results

The overall pathologic concordance rate between the CFB and ESD specimens was 68.57%. 55 cases of CFB maintained low-grade intraepithelial neoplasia (LGIN) under ESD,18 cases (23.1%) diagnosis for high-grade intraepithelial neoplasia (HGIN), 5 cases (6.4%) diagnosis for cancer. Moreover, 10 cases of CFB maintained HGIN under ESD. Lesions with surface hyperemia (44.4% vs. 27.54%) or surface ulcer (57.14% vs.26.76%) were more likely to cancerate (P<0.05).

Conclusion

endoscopic biopsy in the diagnosis of low-grade intraepithelial neoplasia, may exist or progression to high-grade intraepithelial neoplasia, some may have cancer, should take active treatment measures.

Is screening and surveillance for early detection of gastric cancer needed in Korean Americans?

The incidence rate of gastric cancer in Korean Americans is over five times higher than that in non-Hispanic whites, and is similar to the incidence of colorectal cancer in the overall United States population. In Korea, the National Cancer Screening Program recommends endoscopy or upper gastrointestinal series for people aged 40 years and older every 2 years. However, the benefit of gastric cancer screening in Korean Americans has not been evaluated. Based on epidemiologic studies, Korean Americans appear to have more similar gastric cancer risk factors to Koreans as opposed to Americans of European descent, though the risk of gastric cancer appears to decrease for subsequent generations. Therefore, in accordance with recent recommendations regarding screening for gastric cancer in Korea, endoscopic screening for gastric cancer in Korean Americans should be considered, especially in those with known atrophic gastritis/intestinal metaplasia or a family history of gastric cancer. In the future, additional studies will needed to assess whether a screening program for gastric cancer in Korean Americans will result in a survival benefit.

Unusual Causes of Upper Gastrointestinal Bleeding

Upper gastrointestinal (GI) bleeding is an important clinical condition managed routinely by endoscopists. Diagnostic and therapeutic options vary immensely based on the source of bleeding and it is important for the gastroenterologist to be cognizant of both common and uncommon etiologies. The focus of this article is to highlight and discuss unusual sources of upper GI bleeding, with a particular emphasis on both the clinical and endoscopic features to help diagnose and treat these atypical causes of bleeding.

Pathological differences between forceps biopsy specimens and endoscopic resection specimens in early gastric cancer patients

Objective: Endoscopic resection(ER) is effective therapy on EGC and which is treated according to the histological diagnosis of forcep biopsy. But sometimes the histological diagnosis of forcep biopsy and post-ER does not match with each other and it might lead to wrong treatment. The aim of this study is to find the frequency of histologic differences between forcep biopsy and post-ER, and to confirm the characteristics of lesions which make errors. Methods: We selected the confirmed cancer cases of 141 patients of 1359 gastric tumor lesions which were treated under the ER in Eulji university hospital from May 2005 to March 2013. They were sorted by the age and sex of patient, location of lesion, present of ulcer and depression to identify the discordance between forcep biopsy and ER. The discordant group was compared with non-cancer-diagnosed controlled group, retrospectively. Results: 70 cases(5.5%) of 1283 cases of “cancer negative” in forceps biopsy were fo䴸nd to be diagnosed cancer on final diagnosis of cancer by post-ER result. In this discordant group showed characteristics of bigger size that are with more frequently in tumor size D15mm(17.9% vs. 31.4%, p=0.03), have depressed lesion(ᄀ 4.3% vs. 41.4%, p&lt;0.01) and have 䴸lceration(2.4% vs.18.6%, p&lt;0.01) than that of 84 control gro䴸p not diagnosed cancer. Conclusions: In cases of tumor with size D15mm, presented with depressed lesion and ulceration, we should consider combined cancer, even the result of forcep biopsy was negative. Therefore, more careful and accurate resection should be taken with characters listed above.

A randomized trial to determine the diagnostic accuracy of conventional vs. jumbo forceps biopsy of gastric epithelial neoplasias before endoscopic submucosal dissection; open-label study

BACKGROUND AND AIMS

Larger biopsy specimens or increasing the number of biopsies may improve the diagnostic accuracy of gastric epithelial neoplasia (GEN). The aims of this study was to compare the diagnostic accuracies between conventional and jumbo forceps biopsy of GEN before endoscopic submucosal dissection (ESD) and to confirm that increasing the number of biopsies is useful for the diagnosis of GEN.

RESULTS

The concordance rate between EFB and ESD specimens was not significantly different between the two groups [83.1 % (54/65) in JG vs. 79.1 % (53/67) in CG]. On multivariate analyses, two or four EFBs significantly increased the cumulating concordance rate [coefficients; twice: 5.1 (P = 0.01), four times: 5.9 (P = 0.02)]. But, the concordance rate was decreased in high grade dysplasia (coefficient -40.32, P = 0.006).

PATIENTS AND METHODS

One hundred and sixty GENs from 148 patients were randomized into two groups and finally 67 GENs in 61 patients and 65 GENs in 63 patients were allocated to the conventional group (CG) or jumbo group (JG), respectively. Four endoscopic forceps biopsy (EFB) specimens were obtained from each lesion with conventional (6.8 mm) forceps or jumbo (8 mm) forceps. The histological concordance rate between 4 EFB specimens and ESD specimens was investigated in the two groups.

CONCLUSIONS

Before ESD, the diagnostic accuracy of GENs was significantly increased not by the use of jumbo forceps biopsy but by increasing the number of biopsies.

Antral hyperplastic polyp: A rare cause of gastric outlet obstruction

INTRODUCTION

Gastric polyps are usually found incidentally during upper gastrointestinal endoscopic examinations. These polyps are generally benign, with hyperplasia being the most common. While gastric polyps are often asymptomatic, they can cause gastric outlet obstruction.

PRESENTATION OF CASE

A 64 years-old female patient presented to our polyclinic with a history of approximately 2 months of weakness, occasional early nausea, vomiting after meals and epigastric pain. A polypoid lesion of approximately 25mm in diameter was detected in the antral area of the stomach, which prolapsed through the pylorus into the duodenal bulbus, and subsequently caused gastric outlet obstruction, as revealed by upper gastrointestinal endoscopy of the patient. The polyp was retrieved from the pyloric canal into the stomach with the aid of a tripod, and snare polypectomy was performed.

DISCUSSION

Currently, widespread use of endoscopy has led to an increase in the frequency of detecting hyperplastic polyps. While most gastric polyps are asymptomatic, they can cause iron deficiency anemia, acute pancreatitis and more commonly, gastric outlet obstruction because of their antral location. Although there are no precise principles in the treatment of asymptomatic polyps, polyps >5mm should be removed due to the possibility of malignant transformation.

CONCLUSION

According to the medical evidence, polypectomy is required for gastric hyperplastic polyps because of the risks of complication and malignancy. These cases can be successfully treated endoscopically.

Discrepancy between endoscopic forceps biopsy and endoscopic resection in gastric epithelial neoplasia

BACKGROUND

Endoscopic forceps biopsy (EFB) is a major diagnostic procedure for gastric epithelial neoplasia (GEN). However, discrepancy between the result of EFB and endoscopic resection (ER) is not uncommon. Thus, there is controversy over whether specimens obtained by EFB are optimal for diagnosis of GEN. We investigated the discrepancy between EFB and ER in the diagnosis of GEN.

METHODS

A total of 1,850 GEN cases were histologically diagnosed with EFB, including 954 low-grade dysplasias (LGDs), 315 high-grade dysplasias (HGDs), and 581 carcinomas. Following diagnosis with EFB, all patients were treated with ER. We retrospectively reviewed the pathologic findings and patient characteristics and analyzed predictors for the discrepancy between the two procedures (largest diameter, number of biopsy fragments, number of biopsy fragments/largest diameter, location, macroscopic type, color, surface unevenness, and erosion).

RESULTS

The overall discrepancy rate between EFB and ER was 31.7 % (587/1,850). Among the discordant group, 440 (23.9 %) cases showed a higher grade of disease after ER; 229 of the 954 LGDs (24.0 %) were diagnosed as HGD or carcinoma, 166 of the 315 HGDs (52.7 %) as carcinoma, and 45 of the 581 differentiated carcinomas (7.7 %) as undifferentiated carcinoma. In the LGD group with EFB, the largest diameter (≥1.8 cm; P < 0.001), surface unevenness (P = 0.014), and depressed macroscopic type (P < 0.001) were factors associated with discrepancy. In the carcinoma group with EFB, flat macroscopic type (P = 0.043) was the only significant factor. In the HGD group with EFB, there were no significant factors for discrepancy.

CONCLUSIONS

EFB can be insufficient for diagnosing GENs, and ER can be considered not only as treatment but also as a diagnostic modality in GEN. It is especially pertinent to all cases of HGD regardless of their endoscopic features and to cases of LGDs with the largest lesion diameter ≥1.8 cm, surface unevenness, or a depressed macroscopic type.

Endoscopic resection for gastric epithelial neoplasia: how to solve pathological discrepancy and achieve curative resection?

OBJECTIVE

Endoscopic resection (ER) was introduced to China from Japan, while most pathologists are influenced by Western criteria. Japanese and Western pathologists have debated for decades how best to distinguish between gastric intraepithelial neoplasia (GIEN) and early gastric cancer (EGC). In this study we aimed to find out how to solve this pathological discrepancy and improve the curative resection of lesions based on our experiences.

METHODS

In total, 143 patients with GIEN or EGC were treated by ER in our hospital from April 2008 to April 2012. The risk factors related to the degree of malignancy of the lesions and the non-curability of ER were analyzed. Pathological discrepancy between forceps biopsies and ER specimens was also compared.

RESULTS

According to the histological types of the ER specimens, there were 67 patients with low-grade intraepithelial neoplasia (LGIN), 35 with high-grade intraepithelial neoplasia (HGIN) and 41 with EGC. The ER histological type was significantly correlated with gender, ER method, macroscopic type, tumor size, ulcer and histological type of the forceps biopsy (P < 0.05). The discrepancy between forceps biopsy and ER specimens was 41.3% (59/143). Furthermore, the depth of tumor invasion and ER histological type were associated with the curative resection of HGIN and EGC (P < 0.05).

CONCLUSIONS

The pathological discrepancy shows that patients with HGIN in forceps biopsy should be considered candidates for ER. The risk factors of lesion malignancy and ER curability indicate the great importance of pretreatment evaluation for ER.

Application of magnifying endoscopy with narrow-band imaging in diagnosing gastric lesions: a prospective study

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) can more clearly assess the surface pattern and microvascular architecture of gastric lesions.

OBJECTIVE

To evaluate the diagnostic efficacy of ME-NBI in patients with early gastric cancer.

DESIGN

Prospective study.

SETTING

Single academic center.

PATIENTS

This study involved 164 suspected gastric lesions in 146 consecutive patients who underwent ME-NBI for additional differential diagnosis before treatment.

INTERVENTION

ME-NBI findings were classified into 3 groups based on irregularities, absence of surface pattern, and microvascular architecture. All lesions were treated endoscopically or surgically, and ME-NBI diagnosis was compared with histopathological findings.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of real-time ME-NBI diagnosis were determined.

RESULTS

The sensitivity, specificity, and accuracy of ME-NBI were 97.3%, 84.4%, and 90.2%, respectively, in distinguishing between cancerous and noncancerous lesions and were 92.3%, 89.7%, and 90.4%, respectively, in distinguishing undifferentiated from differentiated adenocarcinoma. ME-NBI accurately predicted depth of invasion in 37 of 39 differentiated adenocarcinomas (95%).

LIMITATIONS

The sample size was relatively small.

CONCLUSIONS

ME-NBI can successfully distinguish between cancerous and noncancerous lesions and between undifferentiated and differentiated adenocarcinomas. Of the 3 patterns on ME-NBI, type A is mainly characteristic of noncancerous lesions, type B is a good indicator of differentiated adenocarcinoma and intramucosal/superficially invasive cancers, and type C is indicative of undifferentiated adenocarcinoma or differentiated cancer with deep submucosal invasion.

Discrepancies in histologic diagnoses of early gastric cancer between biopsy and endoscopic mucosal resection specimens

BACKGROUND

A preoperative histologic diagnosis of neoplasia is a requirement for endoscopic resection (ER). However, discrepancies may occur between histologic diagnoses based on biopsy specimens versus ER specimens. The aim of this study was to assess the rate of discrepancy between histologic diagnoses from biopsy specimens and ER specimens.

METHODS

A total of 1705 gastric lesions, from 1419 patients with a biopsy diagnosis of neoplasia, were treated by ER from September 2002 to December 2008. We compared the histologic diagnosis from the biopsy sample and the final diagnosis from the ER specimen to assess the discrepancy rate. Clinicopathological characteristics of the lesions that were related to the histologic discrepancies were also studied.

RESULTS

An ER diagnosis of gastric cancer was made in 49% (118/241) of lesions diagnosed as borderline lesions from biopsy specimens; this included adenomas and lesions difficult to diagnose as regenerative or neoplastic. The size, existence of a depressed area, and ulceration findings were significant factors observed in these lesions. An ER diagnosis of differentiated type cancer was obtained for 17% (12/63) of lesions diagnosed as undifferentiated type cancer from the biopsy specimens; for these lesions, the color and a mixed histology were significant factors related to the histologic discrepancies.

CONCLUSION

A biopsy diagnosis of borderline lesions or undifferentiated type cancer is more likely to disagree with the diagnosis from ER specimens. Endoscopic characteristics should be considered together with the biopsy diagnosis to determine the treatment strategy for these lesions.

Treatment strategy for gastric non-invasive intraepithelial neoplasia diagnosed by endoscopic biopsy

Treatment strategies, whether as follow-up or “total incisional biopsy” for gastric noninvasive intraepithelial neoplasia diagnosed by examination of an endoscopic forceps biopsy specimen, are controversial due to problems associated with the diagnostic accuracy of endoscopic forceps biopsy and questions about the safety and efficacy of endoscopic treatment. Based on the histological findings of the biopsy specimen, it is difficult to differentiate between reactive or regenerative changes, inflammation and neoplastic changes, intraepithelial and invasive tumors. Therefore, gastric neoplasia diagnosed as noninvasive intraepithelial often develop into invasive carcinoma during follow-up. Recent advances in endoscopic modalities and treatment devices, such as image-enhanced endoscopy and high-frequency generators, may make endoscopic treatment, such as endoscopic submucosal dissection (ESD), a therapeutic option for gastric intraepithelial neoplasia, including low-grade neoplasms. Future studies are required to evaluate whether ESD is a valid strategy for gastric intraepithelial neoplasm with regard to safety and cost effectiveness.

Endoscopic submucosal dissection as a treatment for gastric noninvasive neoplasia: a multicenter study by Osaka University ESD Study Group

BACKGROUND

Treatment with endoscopic submucosal dissection (ESD) for gastric noninvasive neoplasia (NIN) diagnosed by endoscopic forceps biopsy specimen, whether as a follow-up or "total incisional biopsy", is controversial. To validate the use of ESD for total incisional biopsy in NIN, we examined the underdiagnosis rate of NIN and the rates of complication associated with ESD.

METHODS

This is a cross-sectional multicenter retrospective study from 10 hospitals. Subjects diagnosed with NIN (equivalent to category 3 or 4.1 of the Vienna classification) by endoscopic forceps biopsy and treated with ESD were included. From March 2003 to December 2009, a total of 468 subjects were included and analyzed. The underdiagnosis rate was defined as the proportion of lesions diagnosed with adenocarcinoma after ESD. We assessed the complete en-bloc resection rate and the complication rate of ESD.

RESULTS

Among the 468 subjects with NIN, 205 were diagnosed with adenocarcinoma after ESD, with an underdiagnosis rate of 44% (95% confidence interval: 39-49%). Two submucosal cancer lesions had invaded beyond 500 μm and one had lymphatic involvement. The complete en-bloc resection rate was 97%. The incidences of post-ESD bleeding, perforation, and serious complications were 5.5, 4.7, and 0.43%, respectively. There were no procedure-related deaths.

CONCLUSIONS

In this large-scale, multicenter cross-sectional study, over 40% of the noninvasive gastric neoplasia specimens were determined to have adenocarcinoma, and the ESD-related complication rate was relatively low. Therefore, ESD was useful and may be a therapeutic option for gastric NIN.

Is endoscopic forceps biopsy enough for a definitive diagnosis of gastric epithelial neoplasia?

BACKGROUND AND AIM

Endoscopic forceps biopsy (EFB) as the primary histological diagnosis of gastric epithelial neoplasia (GEN) is debated in the era of endoscopic resection (ER). Our aim was to investigate the diagnostic reliability of EFB in patients with GEN compared with ER specimens as the reference standard for the final diagnosis in a large consecutive series.

METHODS

This was a cross-sectional retrospective study at a tertiary-referral center. A total of 354 consecutive patients with 397 GENs underwent ER (endoscopic mucosal resection or endoscopic submucosal dissection). Discrepancy rates between the histological results from EFB and ER specimens were assessed. Discrepancies that could affect patient outcome or clinical care were considered major.

RESULTS

The overall histological discrepancy rate between EFB and ER specimens was 44.5% (95% confidence interval [CI], 39.7-49.5%) among the enrolled patients. The overall discrepancy rate was significantly higher in the intraepithelial neoplasia (IEN) group than in the carcinoma group (49.8% vs 25.6%, P < 0.001). The major discrepancy rate was also significantly higher in the IEN group than in the carcinoma group (36.6% vs 7.0%, P < 0.001). In subgroup analysis of the IEN group, a major histological discrepancy rate of 33.6% (70/208) for low-grade and 42.7% (44/103) for high-grade IEN was found, respectively.

CONCLUSIONS

Endoscopic forceps biopsy was insufficient for a definitive diagnosis and therapeutic planning in patients with GEN. ER should be considered as not only definitive treatment but also a procedure for a precise histological diagnosis for lesions initially assessed as GEN by forceps biopsy specimens.

New Endoscopic Techniques: Challenges and Opportunities for Surgical Pathologists

In recent years, significant clinical and technological advances have been made in endoscopic methods for diagnosis and treatment of early gastrointestinal neoplasms. However, essential information related to these novel techniques and their implications for practicing surgical pathologists have largely been missing in the general pathology literature. This article provides a general introduction to these novel therapeutic and diagnostic methods, and discusses their indications, contraindications, and potential limitations. The article aims to enable surgical pathologists to interact more efficiently with basic scientists and clinical colleagues to help implement and improve the existing clinical methods and to advance the new technologies.

Intermittent gastric outlet obstruction caused by a prolapsing antral gastric polyp

Most gastric polyps have an asymptomatic presentation and are an incidental finding on upper endoscopy. Symptomatic presentations can range from an ulcerated polyp leading to anemia and occult bleed to complete gastric outlet obstruction. We report a case of an 89-year-old woman who presented with postprandial nausea and early satiety. Her upper endoscopy revealed a 2 cm pedunculated hyperplastic polyp arising from the antrum of the stomach which was seen prolapsing into the pylorus causing intermittent gastric outlet obstruction. In the present report, we statistically analyzed 39 prolapsing gastric polyps previously reported in the English literature and demonstrate the current utility of monopolar snare polypectomy in establishing a histological diagnosis while offering simultaneous treatment. Additionally, we review the literature for the management of all hyperplastic gastric polyps in relation to advancements in digestive endoscopy.

Coexpression of two distinct muscle acetylcholine receptor alpha-subunits during development

The nicotinic acetylcholine receptor is a ligand-gated channel that mediates signalling at the vertebrate neuromuscular junction. It is a pentameric complex of four different subunits, assembled with a stoichiometry of alpha 2 beta gamma delta. Muscle-like alpha-subunits have been cloned from Torpedo, mouse, calf, rat, chicken, human and Xenopus, and only a single alpha-subunit complementary DNA from each species has been detected. We report here the cloning and characterization of a second muscle alpha-subunit cDNA from Xenopus, and show that this and a previously reported Xenopus alpha-subunit cDNA are encoded by distinct genes. The novel alpha-subunit reported here is expressed uniquely in oocytes; but both types of alpha-subunit are coexpressed throughout muscle development. This latter observation indicates that the expression of these two alpha-subunits is different from a previously reported developmental 'subunit-switch' mechanism used to generate channel diversity.