Bloc biopsy by using submucosal endoscopy with a mucosal flap method for gastric subepithelial tumor tissue sampling (with video)

Endoscopic ultrasound-guided fine-needle aspiration for gastrointestinal subepithelial lesions

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20 mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

Utility and advantage of the unroofing technique for gastrointestinal subepithelial tumors: A multicenter retrospective cohort study

Background and aim

Various techniques for direct biopsy from gastrointestinal subepithelial tumors (SETs) have been reported, although no standard method has been established. A common feature of these techniques is the removal of overlaying mucosa to enable direct biopsies from the SETs. These methods have been synthesized under the collective term "unroofing technique". We conducted a multicenter retrospective study to assess its efficacy and identify potential complications.

Methods

This study was conducted in 10 hospitals and involved all eligible patients who underwent unroofing techniques to obtain biopsies for gastrointestinal SETs between April 2015 and March 2021. The primary endpoint was the diagnostic accuracy of the unroofing technique, and the secondary endpoints were the incidence of adverse events and the factors contributing to the accurate diagnosis.

Results

The study included 61 patients with 61 gastrointestinal SETs. The median tumor size was 20 mm, and the median procedure time was 38 min, with 82% successful tumor exposure. The rate of pathological diagnosis was 72.1%. In 44 patients with a pathological diagnosis, two showed discrepancies with the postresection pathological diagnosis. No factors, including facility experience, organ, tumor size, or tumor exposure, significantly affected the diagnostic accuracy. There was one case of delayed bleeding and two cases of perforation.

Conclusion

The diagnostic yield of the unroofing technique was acceptable. The unroofing technique was beneficial regardless of institutional experience, organ, tumor size, or actual tumor exposure.

Boring biopsy with rapid on-site evaluation for gastric gastrointestinal stromal tumor: A pilot study

One of 4 patients (25%) and 2 of 3 patients (67%) were correctly diagnosed by conventional and hot boring biopsies, respectively. The median procedure time of conventional and hot boring biopsies was 21 (range, 13-33) and 17 (range, 16-23) min, respectively. Rapid on-site evaluation was performed totally 12 times in 7 patients. The positive and negative predictive values of rapid on-site evaluation for gastrointestinal stromal tumor were 0.5 (0.12-0.88) and 1.0 (0.42-1.00), respectively.

Tissue diagnosis necessary for small endoscopic ultrasound-suspected gastric gastrointestinal stromal tumors 2 cm or less in size: A prospective study focusing on the endoscopic incisional biopsy

BACKGROUND AND AIM

The small endoscopic ultrasound (EUS)-suspected gastric gastrointestinal stromal tumors (GISTs), gastric subepithelial tumors at the muscularis propria layer on EUS, are detected frequently. Bite-on-bite forceps biopsy and EUS-guided tissue sampling yield variable results. This study aimed to analyze clinicopathologic features of the small EUS-suspected gastric GISTs 2 cm or less in size and to evaluate the efficacy and safety of the endoscopic incisional biopsy (EIB) for these small tumors.

METHODS

This prospective study investigated 70 patients with small EUS-suspected gastric GISTs 2 cm or less in size in two stages. Firstly, 30 patients were recruited for the efficacy and safety evaluation of the EIB. Secondly, 40 patients were randomly assigned to receive either EIB or the bite-on-bite biopsy for comparison of the diagnostic yield, procedure time, and adverse event rate.

RESULTS

Combining two study stages, leiomyoma (74%) was diagnosed histologically to outnumber GIST (26%) with a diagnostic rate of 94% for patients receiving EIB. KIT exon 11 mutations (50%) and PDGFRA exon 12 mutations (16%) were detected in the small gastric GISTs. In the direct comparison, the diagnostic yield of EIB and the bite-on-bite biopsy was 85% and 50%, respectively (P = 0.018). There was no statistically significant difference of the mean procedure time or adverse event rate between these two groups.

CONCLUSIONS

Leiomyoma is more common than expected among these small tumors. Tissue diagnosis with an effective and safe sampling technique, such as EIB, is necessary for making further clinical decisions.

Simplified Submucosal Tunneling Biopsy Using Clip-With-Line Traction and Closure for Gastric Subepithelial Lesion

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) has emerged as a standard and convenient method for the sampling of subepithelial lesions (SELs). Immunohistological analysis is required to definitively distinguish mesenchymal tumors; however, EUS-FNA provides insufficient material to achieve this, especially for small SELs < 2 cm. We therefore previously reported a novel submucosal tunneling biopsy (STB) technique that utilizes endoscopic submucosal dissection (ESD) for sampling SELs. However, unresolved advanced technical issues have hindered its widespread application. Currently, a counter-traction technique is used to facilitate ESD. We here describe a technically simplified STB technique using clip-with-line traction for gastric SELs.

Reasons for Diagnostic Failure in Forty-Five Consecutive Mucosal Cutting Biopsy Examinations of Gastric Subepithelial Tumors

BACKGROUND/AIMS

Mucosal cutting biopsy (MCB) is useful for the histopathological diagnosis of gastric subepithelial tumors (SETs). However, there is little information on cases in which MCB did not establish a diagnosis. In the current study, we aimed to investigate the characteristics of cases in which MCB was unsuccessful.

METHODS

Cases in which MCB was used to histopathologically diagnose gastric SETs at Kobe University Hospital between August 2012 and October 2018 were retrospectively reviewed.

RESULTS

Forty-five cases in which MCB was used to diagnose 43 gastric SETs in 43 patients were analyzed. The median tumor size was 20 mm (range, 8-50 mm). Pathological examinations resulted in definitive and suspected diagnoses and no diagnosis in 29 (gastrointestinal stromal tumor: n=17, leiomyoma: n=7, aberrant pancreas: n=3, others: n=2), 6, and 10 cases, respectively. Failure to expose the tumor according to retrospective examinations of endoscopic images was significantly associated with no diagnosis. Other possible explanations included a less elevated tumor, biopsy of the surrounding field instead of the tumor due to the mobility, and poor endoscope maneuverability due to the tumor being close to the cardia.

CONCLUSION

Clear exposure of gastric SETs during MCB may improve the diagnostic rate of such examinations.

Diagnostic yield of deep biopsy via endoscopic submucosal dissection for the diagnosis of upper gastrointestinal subepithelial tumors: a systematic review and meta-analysis

Background:

Conventionally, endoscopic ultrasound-guided fine-needle aspiration and biopsy (EUS-FNA)/EUS-FNB) has been used for tissue diagnosis of upper gastrointestinal (GI) subepithelial tumors (SETs). However, deep biopsy (DB) via endoscopic submucosal dissection (ESD) is emerging as an alternative technique, given the inadequate tissue sampling with EUS-FNA/EUS-FNB. Our aim was to conduct a systematic review and meta-analysis to report the overall diagnostic yield of DB via ESD for upper GI SETs.

Methods:

PubMed, Cochrane Library and Web of Science databases were searched to identify studies (from commencement to Oct 2017) that reported the DB via ESD technique for diagnosis of upper GI SETs. The primary outcome of interest was the method’s overall diagnostic yield and the secondary outcome was to the occurrence of complications. The meta-analysis was performed using the DerSimonian and Laird random-effects model.

Results:

A total of 7 studies, comprising 209 patients with a mean age of 57.3 years, were included in the final meta-analysis. The overall pooled diagnostic yield of DB via ESD for upper GI SETs was 95% (95% confidence interval [CI] 84.91-99.98, I²=78.2%). Overall, pooled outcomes of major bleeding and perforation in our meta-analysis was noted in 0.07% (95%CI 0.00-2.32, I²=0%) and 0% (95%CI 0.00-1.70, I²=0%) respectively. Data regarding major bleeding and perforation rates were not reported in 2 studies. Substantial heterogeneity was observed in our meta-analysis.

Conclusion:

DB via ESD is an effective and safe procedure for diagnosing upper GI SETs. Further multicenter randomized controlled trials are needed to validate these findings.

Mucosal incision-assisted biopsy versus endoscopic ultrasound-guided fine-needle aspiration with a rapid on-site evaluation for gastric subepithelial lesions: A randomized cross-over study

OBJECTIVES

This study aimed to compare the diagnostic yield of mucosal incision-assisted biopsy (MIAB) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with a rapid on-site evaluation (ROSE) for gastric subepithelial lesions (SEL) suspected of being gastrointestinal stromal tumors (GIST) with an intraluminal growth pattern.

METHODS

This was a prospective randomized, cross-over multicenter study. The primary outcome was the diagnostic yield of EUS-FNA and MIAB. The secondary outcomes were the technical success rate, complication rate, procedure time and biopsy frequency.

RESULTS

A total of 47 patients were randomized to the MIAB group (n = 23) and EUS-FNA group (n = 24). There was no significant difference in the diagnostic yield of MIAB and EUS-FNA (91.3% vs 70.8%, P = 0.0746). The complication rates of MIAB and EUS-FNA did not differ to a statistically significant extent. The mean procedure time in the MIAB group was significantly longer than that in the EUS-FNA group (34 vs 26 min, P = 0.0011).

CONCLUSIONS

The diagnostic yield of MIAB was satisfactorily as high as EUS-FNA with ROSE for gastric SEL with an intraluminal growth pattern.

Examine the Availability and Safety of Mucosal Cutting Biopsy Technique for Diagnosis of Gastric Submucosal Tumor

Objectives

Differentiating gastrointestinal stromal tumor (GIST) from other submucosal tumors (SMTs) is important in diagnosing SMT. GIST is an immunohistological diagnosis that cannot be made from images alone. Tissue sampling of tumor sites is thus becoming increasingly important. In this study, the utility and associated complications of mucosal cutting biopsy (MCB) for gastric SMTs were investigated.

Methods

This was a case series study. The subjects were patients aged ≥20 years old in whom an SMT was seen on esophagogastroduodenography and who underwent MCB between January 2012 and December 2016. Patient information, endoscopy findings, gastric SMT size, pathological diagnosis, and other information were gathered from medical records. The SMT size was the maximum diameter that could be visualized on EUS. The pathological diagnosis was made with hematoxylin-eosin staining, with immunostaining added to diagnose GIST. The endpoint was the histopathological diagnostic yield. Risk assessment using the Miettinen classification and modified Fletcher classification was also done for GISTs treated with surgery.

Results

The mean tumor diameter was 15.4 mm. The tumor diameter was ≥20 mm in seven patients and <20 mm in 23 patients. The tissue-acquiring rate was 93.3%. A histological diagnosis could not be made in two patients. The only complication was that bleeding required endoscopic hemostasis during the procedure in one patient, but no subsequent bleeding or no postoperative bleeding was seen.

Conclusions

MCB is an appropriate and safe procedure in the diagnosis of gastric SMTs. Many hospitals will be able to perform MCB if they have the environment, including skills and equipment, to perform endoscopic submucosal dissection.

2007-2019: a "Third"-Space Odyssey in the Endoscopic Management of Gastrointestinal Tract Diseases

PURPOSE OF REVIEW

The main scope of this review article is to introduce readers to the innovative field of third-space endoscopy and offer a closer look at its history, milestones, and procedure spectrum while discussing ongoing and future challenges arising from its increasing adoption worldwide.

RECENT FINDINGS

Over the past few years, third-space endoscopy has been utilized in various diagnostic and interventional procedures performed throughout the gastrointestinal tract: obliteration of Zenker's diverticulum, myotomy for achalasia, gastroparesis or Hirschsprung's disease, biopsy or removal of subepithelial tumors, stricture management, post-per-oral endoscopic myotomy endoscopic fundoplication, and mediastino-, thoraco-, and peritoneoscopy. Third-space endoscopic interventions have revolutionized the management of esophageal motility disorders, gastroparesis, and gastrointestinal tract subepithelial tumors. Despite the high efficacy and safety of such interventions, some common (e.g., the high level of necessary endoscopic skill) and unique for each procedure (e.g., post-procedure gastroesophageal reflux or poor outcomes in patient subgroups) challenges still remain. Through a dedicated endoscopic training, a rigorous pre-procedure patient evaluation and selection, and the application of modified or new techniques, challenges can be overcome thus establishing existing procedures and paving the way for additional breakthroughs in the field of third-space endoscopy.

Canalization technique to obtain deep tissue biopsy of gastrointestinal subepithelial tumors as an alternative to conventional known techniques

Background and Objectives

The most accurate technology to detect and diagnose subepithelial tumors (SETs) is the endoscopic ultrasonography (EUS) combined with puncture techniques, such as the endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) or the endoscopic ultrasonography-guided fine-needle biopsy. Going further in the improvement of the results of tumor samples obtained endoscopically to diagnose the SETs, the canalization technique guided by miniprobes (MPs) to obtain biopsies of SET could be an alternative to EUS-FNA. The objective of this study is to analyze the results of samples obtained by this procedure.

Materials and Methods

A multicenter, retrospective study of a review of a database of 32 consecutive patients with a SET in the digestive tract, from 2000 to 2015 was conducted. All patients underwent EUS-performed by MP, to define the size, internal echostructure, and layer of origin of tumor. Once the echostructure was defined, it proceeded to the canalization technique to arrive to the tumor tissue.

Results

The average diameter of SETs in this series (32 patients) was about 21.6±11 mm (range: 5-41 mm). The diagnostic accuracy was 28/32, 87.50% (Confidence interval 95%: 76.04%-98.99%), and there were no major complications. All procedures were performed on outpatients, none of which required additional hospitalization. The 50% of patients were operated or endoscopically resected and in all cases, the previous pathological diagnosis was confirmed.

Conclusions

This is a feasible, safe, and effective procedure that allows to access to inside of SET to obtain deep biopsies. Tumor samples obtained by deep biopsy, with prior performing of the canalization technique guided by MP, were sufficient for histopathological and immunohistochemical diagnosis and similar to those obtained with other known methods (FNA Trucut, ProCore^®, etc.). However, more prospective comparative studies with a larger number of patients and different specialists carrying out the procedure to reach a higher statistical significance are necessary.

The Advantage of an Endoscopic Submucosal Tunneling Technique for Rectal Carcinoid Tumors

Endoscopic treatment can be a curative option for small carcinoid tumors with an extremely low risk of metastasis. Since most carcinoid tumors are characterized by a specific growth pattern in the submucosal (SM) layer, specialized endoscopic techniques for deeper resection to achieve clear vertical margins are needed. The endoscopic submucosal dissection (ESD) method in the SM space is superior to conventional endoscopic mucosal resection. However, the standard ESD technique sometimes fails to provide complete deep SM dissection due to insufficient SM lifting. Here, to resolve this problem, we describe our initial experience with an endoscopic SM tunneling technique that is effective for treating rectal carcinoid tumors.

Interventional endoscopic ultrasound for a symptomatic pseudocyst secondary to gastric heterotopic pancreas

Heterotopic pancreas (HP) is a relatively uncommon entity that is defined as pancreatic tissue without a true anatomical or vascular connection to the pancreas. HP does not cause symptoms in most cases but can occasionally produce various manifestations, including nausea, vomiting, abdominal pain, and even heterotopic pancreatitis. Here, we report an unusual case in which heterotopic pancreatitis complicated by the formation of a pseudocyst that caused gastric outlet obstruction was diagnosed based on serum hyperamylasemia and findings from endoscopic ultrasonography (EUS)-guided fine needle aspiration (EUS-FNA) cytology. EUS-guided single pigtail stent insertion was successfully performed for recurrent gastric outlet obstruction. The patient has remained healthy and symptom-free during 4 years of surveillance. In the context of the relevant literature, the described case is a rare case of HP complicated by a pseudocyst treated via EUS-FNA and stent insertion.

Comparison of submucosal tunneling biopsy versus EUS-guided FNA for gastric subepithelial lesions: a prospective study with crossover design

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound-guided fine needle aspiration (FNA) for gastrointestinal subepithelial lesions (SELs) has limited diagnostic accuracy due to technical problems and small lesion size. We previously reported a novel submucosal tunneling biopsy (STB) technique for sampling SELs. This study aimed to evaluate the diagnostic ability and safety of STB compared to that of FNA for SELs.

PATIENTS AND METHODS

The study was a non-randomized, prospective comparative study with crossover design in patients with endoluminal gastric SELs. Forty-three patients, including 29 cases with lesions < 2 cm were enrolled. A crossover design with 2 intervention stages (Group A: FNA followed by STB for 23 SELs, Group B: STB followed by FNA for 20 SELs) was implemented. The primary outcome was the diagnostic yield (DY). Secondary outcomes were technical success rate, procedure time, complication rate, and sample quality.

RESULTS

The DY of STB was significantly higher than that of FNA (100 % vs. 34.8 %; P  < 0.0001) in group A, including 100 % in overall STB. The technical success rate of STB was significantly higher than that of FNA (100 % vs. 56.5 %; P  = 0.0006), whereas the median procedure time of STB was significantly longer than that of FNA (37 minutes vs. 18 minutes; P  < 0.0001). The median specimen area of STB samples was markedly larger than that of FNA samples (5.54 mm 2 vs. 0.69 mm 2 ; P  < 0.001). No complications occurred in either method.

CONCLUSIONS

 STB had significantly superior diagnostic ability and a more adequate sample quality than FNA for endoluminal gastric SELs, indicating the suitability of STB for small SELs.

CLINICAL TRIAL REGISTRATION

UMIN 000006754.

Drill needle aspiration biopsy for submucosal tumors in an experimental study

BACKGROUND AND AIMS

EUS-guided FNA biopsy has been widely performed to aid in the diagnosis of submucosal tumors (SMTs). However, in cases of small tumors, the diagnostic yield of EUS-FNA is poor. Therefore, it is necessary to develop a new needle for the diagnosis. We developed a device with a new mechanism that we refer to as a drill needle aspiration biopsy (DNAB). The aim of this study was to evaluate the use of DNAB in resected gastric SMT specimens.

METHODS

A drill needle with a sharp tip and wide ditch was inserted into a catheter for angiography. Continuous suction is enabled through the catheter at the tip. DNAB was performed with one pass and one stroke in 13 gastric SMTs resected by operation. Similarly, FNA was performed by one pass and ten strokes. These gastric tumors included nine diagnosed gastrointestinal stromal tumors and four undiagnosed SMTs by preoperative examinations. The tissue quantity between DNAB and FNA was macroscopically and microscopically examined.

RESULTS

All 13 drill biopsy specimens were obtained. Additionally, all 13 gastric SMTs, including 4 undiagnosed tumors, could be diagnosed by DNAB. The quantity of each specimen obtained by DNAB was macroscopically and microscopically much greater than that by FNA. In particular, for tumors <25 mm in the longer axis, the ratio of microscopic diagnosable cases was 100 % (7/7) for DNAB and 42.9 % (3/7) for FNA.

CONCLUSIONS

DNAB is a novel method that can obtain more tissue than FNA for small gastric SMT.

Efficacy of single-incision needle-knife biopsy for sampling subepithelial lesions

Background and study aims Single-incision needle-knife (SINK) biopsy is a diagnostic method for acquiring tissue samples for subepithelial lesions (SELs). A single linear incision is made in the overlying mucosa and tissue samples are obtained by passing conventional biopsy forceps through the opening and deep into the lesion. The aim of this study was to describe the efficacy and safety of this technique. Patients and methods Consecutive patients who underwent SINK biopsy for an upper gastrointestinal SEL between October 2013 and September 2015 were retrospectively reviewed. Results Forty-nine patients underwent 50 SINK biopsies. Sufficient sampling for a definite pathologic diagnosis was obtained in 42 (86 %) cases, with 91 % (40/44) having sufficient sample to perform immunohistochemistry when deemed clinically relevant. Of the 26 patients with prior non-diagnostic biopsies or FNA, a specific diagnosis was obtained in 85 % (22/26). There were no significant adverse events. Conclusions SINK biopsy is a safe and feasible strategy for obtaining a definitive tissue diagnosis with immunohistochemistry for SELs.

Clinical implications of doubling time of gastrointestinal submucosal tumors

AIM

To evaluate the efficacy of doubling time (DT) of gastrointestinal submucosal tumors (GIST).

METHODS

From April 1987 through November 2012, a total of 323 patients were given a final histopathological diagnosis of GISTs on surgical resection or endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in Kitasato University East Hospital or Kitasato University Hospital. We studied 53 of these patients (34 with resected tumors and 19 with unresected tumors) whose tumors could be measured on EUS on at least two successive occasions. The histopathological diagnosis was GIST in 34 patients, leiomyoma in 5, schwannoma in 3, ectopic pancreas in 1, hamartoma in 1, cyst in 1, Brunner’s adenoma in 1, and spindle-cell tumor in 7. We retrospectively calculated the DT of GISTs on the basis of the time course of EUS findings to estimate the growth rate of such tumors.

RESULTS

The DT was 17.2 mo for GIST, as compared with 231.2 mo for leiomyoma, 104.7 mo for schwannoma, 274.9 mo for ectopic pancreas, 61.2 mo for hamartoma, 49.0 mo for cyst, and 134.7 mo for Brunner’s adenoma. The GISTs were divided into risk classes on the basis of tumor diameters and mitotic figures (Fletcher’s classification). The classification was extremely low risk or low risk in 28 patients, intermediate risk in 3, and high risk in 3. DT of GIST according to risk was 24.0 mo for extremely low-risk plus low-risk GIST, 17.1 mo for intermediate-risk GIST, and 3.9 mo for high-risk GIST. DT of GIST was significantly shorter than that of leiomyoma plus schwannoma (P < 0.05), and DT of high-risk GIST was significantly shorter than that of extremely low-risk plus low-risk GIST (P < 0.05).

CONCLUSION

For GIST, a higher risk grade was associated with a significantly shorter DT. Small SMTs should initially be followed up within 6 mo after detection.

Endoscopic ultrasound-guided forceps biopsy from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope

BACKGROUND AND STUDY AIMS

Endoscopic tissue acquisition techniques using needle-knife and biopsy forceps allow abundant tissue acquisition from upper gastrointestinal subepithelial lesions; however, these techniques cannot capture real-time intratumor information. The aim of this study was to evaluate the feasibility of endoscopic ultrasound-guided forceps biopsy (EUS-FB) from upper gastrointestinal subepithelial lesions using a forward-viewing echoendoscope.

PATIENTS AND METHODS

This study was a prospective case series. After mucosal cuts, several specimens were taken using a hot biopsy forceps under real-time EUS visualization. The incision was closed using hemoclips. Diagnostic yield, rate of diagnosable samples obtained under EUS visualization, procedure time, and adverse events were assessed.

RESULTS

Ten patients (median lesion size 16 mm, range 15 - 44 mm) underwent EUS-FB. The overall rate of histological diagnosis by EUS-FB was 100 % (10/10). The rate of diagnosable samples among all cases was 97.6 % (41/42). The median procedure times for EUS-FB and complete closure were 28.5 and 4.5 minutes, respectively. No adverse events occurred.

CONCLUSIONS

This newly developed EUS-FB is feasible and allowed forceps biopsy from upper gastrointestinal subepithelial lesions.

STUDY REGISTRATION

UMIN000015364.

Metastatic pancreatic cancer presenting as linitis plastica of the stomach

Metastatic disease from pancreatic carcinoma involving the stomach is an unusual event, and the pattern of spread in the form of linitis plastica, to our knowledge, has not been reported previously. Local recurrence after curative resection for pancreatic cancer is the most common pattern of disease. We report a case of metastatic pancreatic adenocarcinoma presenting as linitis plastica of the stomach 4 years after curative resection. A 52-year-old man presented with epigastric pain and melaena 4 years after undergoing a Whipple's procedure for a poorly-differentiated pancreatic adenocarcinoma, stage IB; T2N0M0. CT imaging of the abdomen revealed thickening of the gastric wall, and subsequent oesophagogastroduodenoscopy (OGD) revealed diffuse friable erythaematous tissue. The biopsy specimen obtained during the OGD revealed a poorly differentiated adenocarcinoma, with similar appearance to the prior specimen obtained from the pancreas.

Successful mucosal incision-assisted biopsy for the histological diagnosis of duodenal lymphoma: A case report

Tissue sampling of primary duodenal lymphoma is essential for its histological diagnosis. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), which is frequently used for submucosal tumor (SMT)-like duodenal tumors, is adequate for cytological diagnosis, but not for histological diagnosis. Therefore, in the present study, a mucosal incision-assisted biopsy (MIAB) was performed in an 81-year-old woman for the diagnosis of an SMT-like duodenal mass, as tissue sampling for histological analysis using a regular endoscopic biopsy had failed to establish a definite diagnosis of malignant lymphoma. EUS-FNA had also led to poor tissue sampling due to the difficult location of the duodenal tumor. The pathological examination of biopsy samples using MIAB revealed the presence of a diffuse proliferation of atypical lymphocytes, and the expression of cluster of differentiation (CD)20 and CD79a, but no expression of CD3 in the tumor specimens. The patient was diagnosed with diffuse large B-cell lymphoma. To the best of knowledge, this is first report of a case using MIAB as a sampling method for the histological diagnosis of SMT-like primary duodenal lymphoma. This case suggests that MIAB may be an essential method for obtaining tissue samples from SMT-like duodenal tumors.

Differences in miRNA expression profiles between GIST and leiomyoma in human samples acquired by submucosal tunneling biopsy

BACKGROUND AND STUDY AIMS

Small gastrointestinal stromal tumors (GISTs) rarely have malignant potential with poor prognosis. Using conventional imaging to differentiate between small GISTs and leiomyoma, which often have similar characteristics, is difficult but essential in daily practice. Although some studies have reported on the utility of serum c-kit as a biomarker for non-small GIST and specific miRNA, clinical aspects of such testing are controversial. The aim of this study was to identify differences between small GIST and leiomyoma through the investigation of miRNA expression patterns in human cases.

PATIENTS AND METHODS

MiRNA expression was examined in nine GIST (less than low risk, mean 18 mm in size) samples and seven leiomyoma samples acquired by a novel sampling method, submucosal tunneling biopsy (STB), which produces tumor specimens of submucosal tumor (SMT) without contamination of sufficient size to be examined under direct vision. Total RNA was extracted from these tissues and analyzed for miRNA expression patterns by microarray. Subsequently, real-time quantitative polymerase chain reaction (qPCR) were used to confirm specific miRNA overexpression, comparing GISTs with leiomyomas.

RESULTS

Microarray analysis revealed upregulation of the miR-140 family up to 20 times higher in GISTs than in leiomyomas. Real-time qPCR revealed that the expression level of miR-140-5 p in GISTs was 27.86 times higher than in leiomyomas; miR-140-3 p was 12.24 times higher as well.

CONCLUSIONS

The STB method provided suitable SMT samples for miRNA analysis. MiR-140 family members may serve as specific biomarkers to distinguish GIST from leiomyoma.

Histological diagnosis of gastric submucosal tumors: A pilot study of endoscopic ultrasonography-guided fine-needle aspiration biopsy vs mucosal cutting biopsy

AIM: To compare the usefulness of endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) without cytology and mucosal cutting biopsy (MCB) in the histological diagnosis of gastric submucosal tumor (SMT).

METHODS: We prospectively compared the diagnostic yield, feasibility, and safety of EUS-FNAB and those of MCB based on endoscopic submucosal dissection. The cases of 20 consecutive patients with gastric SMT ≥ 1 cm in diameter. who underwent both EUS-FNAB and MCB were investigated.

RESULTS: The histological diagnoses were gastrointestinal stromal tumors (n = 7), leiomyoma (n = 6), schwannoma (n = 2), aberrant pancreas (n = 2), and one case each of glomus tumor, metastatic hepatocellular carcinoma, and no-diagnosis. The tumors’ mean size was 23.6 mm. Histological diagnosis was made in 65.0% of the EUS-FNABs and 60.0% of the MCBs, a nonsignificant difference. There were no significant differences in the diagnostic yield concerning the tumor location or tumor size between the two methods. However, diagnostic specimens were significantly more frequently obtained in lesions with intraluminal growth than in those with extraluminal growth by the MCB method (P = 0.01). All four SMTs with extraluminal growth were diagnosed only by EUS-FNAB (P = 0.03). No complications were found in either method.

CONCLUSION: MCB may be chosen as an alternative diagnostic modality in tumors showing the intraluminal growth pattern regardless of tumor size, whereas EUS-FNAB should be performed for SMTs with extraluminal growth.

Characteristic waffle-like appearance of gastric linitis plastica: A case report

Linitis plastica is a gastric cancer of diffuse histotype that presents in the fundic gland area, and is characterized by thickening of the stomach wall and deformation of the stomach, resulting in a leather bottle-like appearance. A 66-year-old female was admitted to Kagawa University Hospital (Kagawa, Japan) with epigastric pain. X-ray examination revealed reduced gastric distension and deformation of the stomach, which exhibited a leather bottle-like appearance. Endoscopy indicated a depressed lesion in the gastric antrum, and abnormal folds, which crossed to form a waffle-like appearance in the upper gastric body. Analysis of biopsy specimens from the depressed lesion revealed a poorly differentiated adenocarcinoma. Morphological changes in the gastric folds indicated that the tumor had invaded the upper gastric body, therefore, a total gastrectomy was performed. Subsequent pathological findings demonstrated that the tumor had spread from the primary lesion to the upper gastric body. Therefore, the present report recommends that the diagnosis of the spread of linitis plastica-type gastric cancer should include assessments of the primary lesion, as well as evaluation of morphological changes in the gastric folds.

Analysis of the amount of tissue sample necessary for mitotic count and Ki-67 index in gastrointestinal stromal tumor sampling

There are no established opinions concerning whether the amount of tissue affects the accuracy of histological analyses in gastrointestinal stromal tumors (GISTs). The aim of the present study was to investigate the appropriate amount of tissue sample needed for mitotic count based on the risk classification of GISTs and the Ki-67 index using the following three methods: endoscopic ultrasound-guided fine-needle aspiration (FNA), a novel sampling method called tunneling bloc biopsy (TBB), and biopsy forceps followed by TBB (Bf). Forty-three samples (12 FNA, 17 TBB and 14 Bf) diagnosed as GISTs by immunohistological analysis were utilized. The major and minor axes and overlay area of one piece of specimen (OPS) from the three sampling methods were measured using digital imaging software and were analyzed comparatively regarding the acquisition of histological data. The mean major and minor axes (mm) and overlay areas (mm2) were in the order of TBB > Bf > FNA. The evaluable rates by mitotic count and Ki-67 were, respectively, 75% (9/12) and 83.3% (10/12) for FNA samples, 100% (17/17) and 100% (17/17) for TBB samples, and 100% (14/14) and 100% (14/14) for Bf samples (P>0.05). Three FNA samples were judged unevaluable due to too small specimens in overall diagnosis including mitotic count and Ki-67, calculating the cut-off value for the overlay area of OPS as 0.17 mm2. Comparing the concordance rates between the pre- and post-operative samples, TBB samples was significantly better than FNA (P<0.05). Conclusively, while the amounts of tissues obtained by TBB and Bf are unnecessary for the histological assessment of mitotic count and Ki-67 index, developments of the FNA method are needed to minimize sample error. Considering the technical aspects, as well as the size of the specimens, could help to guide therapeutic planning and improve diagnostic yield for GI subepithelial tumors.

Submucosal endoscopy: the new frontier of therapeutic endoscopy

PURPOSE OF REVIEW

Peroral endoscopic myotomy (POEM) and submucosal tunneling and endoscopic resection (STER) have been recently described as minimally invasive therapies for achalasia and gastrointestinal subepithelial tumors originating from the muscularis propria, respectively. This review illustrates the latest developments in the field of submucosal endoscopy, focuses on POEM and sheds light on STER.

RECENT FINDINGS

Multiple studies from the United States, Asia and Europe have shown that POEM is an effective and safe procedure for achalasia when performed by experienced operators with adequate clinical response in 80-90% of patients. Nonetheless, POEM requires a demanding skill set that involves both advanced endoscopic skills and knowledge of surgical anatomy. In addition, the endoscopist must have the capability to manage procedural complications. Similarly, STER appears to be an effective therapy for treatment of small and medium sized gastrointestinal tumors originating from the muscularis propria.

SUMMARY

POEM and STER offer minimally invasive and effective treatment alternatives for patients with achalasia, spastic esophageal disorders and upper gastrointestinal tumors originating from the muscularis propria.

Evaluation of gastric submucosal tumors using endoscopically visualized features with submucosal endoscopy

Although the macroscopic characteristics of submucosal tumors (SMTs), such as gastrointestinal stromal tumors (GISTs), have been characterized, the assessment of SMTs by their endoscopically visualized features (EVF; which are observed by endoscopic imaging under direct view) remains unevaluated. The aim of the present study was to investigate the potential of endoscopic diagnostics for SMTs using EVF. The EVF of 26 gastric SMT cases, in which the final pathological diagnosis was obtained by core biopsy using the submucosal endoscopy with mucosal flap method, were retrospectively reviewed. Each type of SMT was classified according to the following five EVF: Color, clarity, shape, tumor coating and solidity. Additionally, the EVF of 13 low-risk GISTs and 13 benign submucosal tumors (BSTs) were comparatively evaluated for the five abovementioned EVF. Similar trends were identified between the low-risk GISTs, granular cell tumors and the schwannoma with regard to EVF. However, while these tumors exhibited cloudy EVF, the leiomyomas tended to exhibit clear EVF. Among SMTs of the heterotopic pancreas type, the EVF demonstrated particularly small nodules of the pancreatic tissue itself. Although the sample size included in the present study is small, a classification system for gastric SMTs was proposed according to the EVF. When compared with the BST group, the GIST group demonstrated a significantly higher frequency of tumors that exhibited a combination of three EVF (white, cloudy and rigid) that are consistent with all gastric GISTs (P<0.05). Gastric SMTs may be classified based on the EVF, which indicates that the EVF possess potential diagnostic value for the differentiation of GISTs from BSTs.

Submucosal tunneling techniques: current perspectives

Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

Indications of endoscopic submucosal dissection for symptomatic benign gastrointestinal subepithelial or carcinoid tumors originating in the submucosa

Endoscopic submucosal dissection (ESD) for upper gastrointestinal (GI) subepithelial tumors (SETs) originating in the muscularis propria (MP) layer is associated with numerous issues regarding secure closure and measures against accidental perforation. However, symptomatic benign GI SETs or carcinoid tumors originating in the submucosa (SM) may be safely resected en-bloc using ESD. In this study, the feasibility and safety of ESD as a novel method for endoscopic resection for such GI SETs revealed on endoscopic ultrasonography (EUS) was investigated. A total of 12 consecutive cases of patients with symptomatic benign SETs (n=3; 1 esophageal hemangioma and 2 gastric lipomas) or small carcinoid tumors (n=9; <10 mm, with an extremely low risk of metastasis) originating in the SM as determined on EUS, between March, 2009 and April, 2013, were retrospectively reviewed. The lesions were resected by ESD after confirming that the tumors originated from the SM. The complication rate following en-bloc resection was also determined. En-bloc resection was achieved in all 12 cases, the mean procedure time was 45 min (range, 20-120 min) and no complications occurred intra- or postoperatively. There was no tumor recurrence or disease-related mortality reported during the follow-up period (median follow-up time, 13.4 months). Histopathological curative resection was achieved with ESD without complications in all 9 cases with carcinoid tumors. Therefore, if EUS reveals a SET originating in the SM without infiltration of the MP and resection is indicated due to the presence of abdominal symptoms, ESD may be a feasible option for diagnostic treatment with minimal invasiveness. However, larger-scale prospective studies are required to establish the feasibility and safety of this procedure.