Preoperative diagnosis of gastrointestinal stromal tumor by endoscopic ultrasound-guided fine needle aspiration

Mutation analysis of gastrointestinal stromal tumors using RNA obtained via endoscopic ultrasound-guided fine-needle aspiration

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is useful for pathologically diagnosing gastrointestinal stromal tumor (GIST) before surgery. However, its role in mutation analysis remains unclear. To examine the feasibility of analyzing GIST mutations using mRNA obtained with EUS-FNA, we prospectively enrolled 41 patients with subepithelial lesion from which EUS-FNA was successfully acquired tissue sample. Thirty-two, 5, and 4 subepithelial lesions were diagnosed as GISTs, schwannomas, and leiomyomas, respectively. After RNA was extracted from FNA sample, RNA was converted to cDNA. Full-length sequence of the KIT cDNA amplified via the polymerase chain reaction (PCR) was successful in 31 (96.9%) out of 32 GIST and three out of 9 non-GIST (33.3%). The KIT mutation statuses of 31 GISTs in which KIT cDNA was amplified were successfully determined through directional sequencing. Furthermore, 15 of 16 surgically excised GISTs exhibited the same mutation status in both the EUS-FNA and resected samples. In vitro experiment, the minimum number of cells required to amplify full-length of KIT cDNA from RNA was one-tenth of that required to amplify KIT exon11 gene from DNA. This study clarifies that mutation analysis using RNA obtained with EUS-FNA is feasible and reliable. Moreover, our data would support that RNA-based mutation is superior to DNA-based mutation analysis in GIST.

Locoregional Residual Esophageal Cancer after Neo-adjuvant Chemoradiotherapy and Surgery Regarding Anatomic Site and Radiation Target Fields: A Histopathologic Evaluation Study

OBJECTIVE

Neoadjuvant chemoradiotherapy followed by surgery establishes a considerable pathologic complete response (pCR) in EC. The aim was to determine site of residual tumor and its prognostic impact.

SUMMARY BACKGROUND DATA

High rates of residual tumor in the adventitial region even inside the radiation fields will influence current decision-making.

METHODS

We evaluated resection specimens with marked target fields from 151 consecutive EC patients treated with carboplatin/paclitaxel and 41.4Gy between 2009 and 2018.

RESULTS

In radically resected (R0) specimens 19.8% (27/136) had a pCR (ypT0N0) and 14% nearly no response (tumor regression grade: tumor regression grade 4-5). Residual tumor commonly extended in or restricted to the adventitia (43.1%; 47/109), whereas 7.3% was in the mucosa (ypT1a), 16.5% in the submucosa (ypT1b) and 6.4% only in lymph nodes (ypT0N+). Macroscopic residues in R0-specimens of partial responders (tumor regression grade 2-3: N = 90) were found in- and outside the gross tumor volume (GTV) in 33.3% and 8.9%, and only microscopic in- and outside the clinical target volume in 58.9% and 1.1%, respectively. Residual nodal disease was observed proximally and distally to the clinical target volume in 2 and 5 patients, respectively. Disease Free Survival decreased significantly if macroscopic tumor was outside the GTV and in ypT2-4aN+.

CONCLUSIONS

After neoadjuvant chemoradiotherapy, pCR and ypT1aN0 were seen in a limited number of R0 resected specimens (19.8% and 7.3%, respectively), whereas 6.4% had only nodal disease (yT0N+). Disease Free Survival decreased significantly if macroscopic residue was outside the GTV and in responders with only nodal disease. Therefore, we should be cautious in applying wait and see strategies.

EUS-guided fine-needle biopsy sampling versus FNA in the diagnosis of subepithelial lesions: a large multicenter study

BACKGROUND AND AIMS

Although conventional EUS-guided FNA (EUS-FNA) has previously been considered first-line for sampling subepithelial lesions (SELs), variable accuracy has resulted in increased use of fine-needle biopsy (FNB) sampling to improve diagnostic yield. The primary aim of this study was to compare FNA versus FNB sampling for the diagnosis of SELs.

METHODS

This was a multicenter, retrospective study to evaluate the outcomes of EUS-FNA and EUS-guided FNB sampling (EUS-FNB) of SELs over a 3-year period. Demographics, lesion characteristics, sensitivity, specificity, accuracy, number of needle passes, diagnostic adequacy of rapid on-site evaluation (ROSE), cell block accuracy, and adverse events were analyzed. Subgroup analyses were performed comparing FNA versus FNB sampling by location and diagnostic yield with or without ROSE. Multivariable logistic regression was also performed.

RESULTS

Two hundred twenty-nine patients with SELs (115 FNA and 114 FNB sampling) underwent EUS-guided sampling. Mean patient age was 60.86 ± 12.84 years. Most lesions were gastric in location (75.55%) and from the fourth layer (71.18%). Cell block for FNB sampling required fewer passes to achieve conclusive diagnosis (2.94 ± 1.09 vs 3.55 ± 1.55; P = .003). The number of passes was not different for ROSE adequacy (P = .167). Immunohistochemistry was more able to be successfully performed in more FNB sampling samples (69.30% vs 40.00%; P < .001). Overall, sensitivity and accuracy were superior for FNB sampling versus FNA (79.41% vs 51.92% [P = .001] and 88.03% vs 77.19% [P = .030], respectively). On subgroup analysis, sensitivity and accuracy of FNB sampling alone was superior to FNA + ROSE (79.03% vs 46.67% [P = .001] and 87.25% vs 68.00% [P = .024], respectively). There was no significant difference in diagnostic yield of FNB sampling alone versus FNB sampling + ROSE (P > .05). Multivariate analysis showed no predictors associated with accuracy. One minor adverse event was reported in the FNA group.

CONCLUSIONS

EUS-FNB was superior to EUS-FNA in the diagnosis of SELs. EUS-FNB was also superior to EUS-FNA alone and EUS-FNA + ROSE. These results suggest EUS-FNB should be considered a first-line modality and may suggest a reduced role for ROSE in the diagnosis of SELs. However, a large randomized controlled trial is required to confirm our findings.

Endoscopic ultrasound-guided fine-needle aspiration cytology in the diagnosis of the gastrointestinal stromal tumor of the stomach

BACKGROUND

This study aims to evaluate the usefulness of endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNAC) in the diagnosis of the gastric gastrointestinal stromal tumor (GIST).

METHODS

We retrospectively investigated the efficacy and accuracy of EUS-FNAC in the diagnosis of gastric GIST. Cytological smears and cytoblock sections including immunohistochemistry and mutational studies from patients diagnosed as gastric GISTs were retrieved.

RESULTS

Thirty patients (mean age 68.8 years, range 32-88 years, Male:Female 1:1.7) were diagnosed by cytological and cytoblock study to have GIST. The size of tumors ranged from 1.6 to 25 cm (mean 6.0 cm). 7 (23%) cases were incidentally discovered. Location was: gastric body 13 (43.3%), fundus 8 (26.7%), antrum 7 (23.3%), cardia 2 (6.7%). The study of removed tumors was correlated with the cytological findings. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 75%, 100%, 100%, 46%, and 96%. There were no false-positive cases. The preoperative risk assessment of 27 cases with cytoblock were: none 3 (11.1%), very low 8 (29.6%), low 12 (44.4%), high 3 (11.1%), insufficient clinical data 1 (3.7%). The follow-up varied from 2 to 120 months (mean 46.7 months). Only 1 patient of the high-risk group died. The most frequent mutations found were those of c-KIT in exon 11.

CONCLUSIONS

Pathological diagnosis was based on a combination of cytological, histopathological, and immunohistochemical features. EUS-FNAC is a reliable, accurate, and safe method for the diagnosis of GIST. The cytoblock allows tumor risk classification and mutational study of the cases.

Thoracoscopic surgery combined with endoscopic creation of a submucosal tunnel for a large complicated esophageal leiomyoma

BACKGROUND

The standard surgical method for symptomatic submucosal tumors (SMTs) or tumors with unclear biological behavior is enucleation. Minimally invasive approaches are usually considered appropriate for surgical enucleation; thus, thoracoscopic and laparoscopic enucleation is performed widely and safely. However, it is sometimes difficult to enucleate large and complicated esophageal tumors using thoracoscopic surgery, and even if rare, there is the risk of requiring thoracotomy or esophagectomy. In the present case, we enucleated a large and complicated leiomyoma safely using a new combined method with endoscopic and thoracoscopic procedures.

CASE PRESENTATION

A 42-year-old woman presented to our hospital for a detailed examination of an abnormal finding in her health check-up chest X-ray images. She complained of upper abdominal pain after eating, and computed tomography revealed an esophageal tumor measuring 60 mm in length surrounding her lower thoracic esophagus. Esophagogastroduodenoscopy revealed a huge complicated SMT at the esophagogastric junction. Cytological examination with endoscopic ultrasound-guided fine-needle aspiration showed that the tumor was a leiomyoma. To enucleate this large and complicated esophageal SMT safely and without damaging the esophageal mucosa, we performed endoscopic and thoracoscopic procedures. We created a submucosal tunnel, endoscopically, and then performed thoracoscopic surgery to enucleate the tumor completely from the esophageal muscularis. Using these combined procedures, we were able to easily mobilize even a complicated tumor of this size from the mucosa and completed the surgery thoracoscopically without difficulty. As a result, the tumor was dissected safely with a minimal defect in the muscularis and without damaging the mucosa. Finally, we closed the defect in the esophageal muscularis with continuous sutures, thoracoscopically, and closed the entry of the submucosal tunnel using clips, endoscopically.

CONCLUSIONS

Using these combined procedures, we safely enucleated a huge complicated esophageal SMT. The increased mobility of the tumor after creating the submucosal tunnel contributed to the minimal defect in the muscular layer and prevented injury to the esophageal mucosa, possibly leading to fewer postoperative complications such as esophageal stenosis and local infection.

Endoscopic ultrasound-guided needle-based confocal laser endomicroscopy in gastrointestinal subepithelial lesions: Feasibility study

BACKGROUND AND AIM

Needle-based confocal laser endomicroscopy (nCLE) allows for real-time optical biopsies during endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Little is known about nCLE imaging of gastrointestinal subepithelial lesions (GI-SEL); therefore, we determined its feasibility.

METHODS

We carried out EUS, nCLE, and finally FNA in 25 patients with GI-SEL between November 2015 and December 2018. We retrospectively compared nCLE findings with pathological findings of EUS-FNA or surgical specimens. For concordance analysis, two endoscopists independently validated representative nCLE images 5 months or more after examinations.

RESULTS

Adequate sample acquisition rate of EUS-FNA was 67% per needle pass and 96% per patient. EUS-FNA was diagnostic in 80% (20/25), suspicious in 4% (1/25), and nondiagnostic in 16% (4/25). nCLE image acquisition rate was 100% and its concordance rate with final pathology was 88% (22/25), which was not significantly different from diagnostic and suspicious EUS-FNA. nCLE could differentiate GI stromal tumors (GISTs) from leiomyoma, in that GISTs were characterized by contrast-enhanced densely populated spindle cell tumors with unenhanced rod-shaped nuclei in 93% of 14 patients, whereas leiomyomas were characterized by narrower spindle cell tumors with fewer and smaller unenhanced nuclei in 100% of three patients. In rectal metastasis from lung adenocarcinoma, some pleomorphic dark nests were observed. At concordance analysis between the two endoscopists' validation results, κ value was 0.560 (P < 0.001), indicating moderate agreement. There were no adverse events associated with nCLE and EUS-FNA.

CONCLUSION

Needle-based confocal laser endomicroscopy can be safe and useful for on-site detection of abnormalities of GI-SEL (UMIN 000013857).

A multivariate prediction model for high malignancy potential gastric GI stromal tumors before endoscopic resection

BACKGROUND AND AIMS

Endoscopic resection is becoming an option in the management of gastric GI stromal tumors (GISTs). Although no consensus has been reached, patients with high malignancy potential GISTs are generally considered to be surgical candidates. However, no systematic preoperative evaluation strategy has yet been developed. The current study was performed to develop a preoperative multivariate model to predict the malignant potential of gastric GISTs.

METHODS

This study consisted of 2 stages. First, a multivariate prediction model for gastric GISTs smaller than 5 cm was developed using a multivariate logistic regression analysis in a retrospective cohort. Next, the prediction model was validated further in a validation cohort of gastric GISTs.

RESULTS

In the developing stage, 275 patients were included. The multivariate analysis demonstrated that independent risk factors for high malignancy potential gastric GISTs smaller than 5 cm were tumor size ≥2 cm (according to cutoff value), an irregular tumor shape, and mucosal ulceration (P < .05). Based on accordant regression coefficients, 3 risk factors were weighted with point values: 1 point for mucosal ulceration, 2 points for an irregular tumor shape, and 3 points for tumor size ≥2 cm. In the validation stage, 186 patients were included. The area under the curve of the prediction model was .80 (95% confidence interval, .73-.85), which was significantly higher than that of tumor size alone (P = .034).

CONCLUSIONS

The independent risk factors for high malignancy potential gastric GISTs smaller than 5 cm were tumor size larger than 2 cm, an irregular tumor shape, and mucosal ulceration. These factors could be used to predict malignancy potential of gastric GISTs in a simple combination.

Characteristic of extra luminal gastric stromal tumor arising from the lesser curvature of the stomach: A case report

RATIONALE

Gastrointestinal stromal tumor (GIST) is one of the most common malignant mesenchymal tumors of the gastrointestinal tract. They generally arise from the fourth layer (muscularis propria) and rarely from the second or third layer. Although the manifestations of gastric stromal tumors are diverse, to our knowledge, there are only several cases of an extra-gastric stromal tumor in the literature appearing with a pedunculation. Pedunculated large GISTs are not frequent and compress the neighboring organs. When they were huge, it is difficult to differentiate the origin of the masses. Thus, in the clinical setting, physicians should pay more attention to the pattern of manifestation of the gastric stromal tumor.

PATIENT CONCERNS

A 62-year-old man had no gastrointestinal symptoms or significant medical and family histories. During the health examination with US, a cystic-solid tumor was found below liver. The results of the physical examination were unremarkable, and routine laboratory data on admission did not show any abnormal findings.

DIAGNOSIS

Computed tomography of the abdomen showed a mixed echoic mass measuring 10 × 8 × 8 cm and located below the liver, adjacent to the gastric antrum. After endoscopic ultrasound-guided fine-needle aspiration, cytopathology showed that the specimen was filled with red blood cells, and it had no malignant cells. Histopathology revealed that the mass was a GIST, and immunohistochemical analysis showed the following: CD117(+), CD34(+), desmin(-), Dog-1(+), Ki-67% <1%, and smooth muscle actin(-).

INTERVENTIONS

Surgical resection was performed on the patient.

OUTCOMES

The lesion was diagnosed as a gastric stromal tumor with a pedicle and an old hemorrhage. The patient's recovery was uneventful. After surgery, computed tomography at the 6-month and 1-year postoperative follow-up visits did not reveal relapse or any metastasis.

LESSONS

In the clinical setting, physicians should pay more attention to the pattern of manifestation of the extra-gastric stromal tumor in patients with a pedicle or hemorrhage. Additionally, endoscopic ultrasound-guided fine-needle aspiration can be used to make an accurate preoperative diagnosis of such diseases, and its findings can serve as an important basis for surgical excision of the lesions.

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.

In vivo real-time diagnosis of endoscopic ultrasound-guided needle-based confocal laser endomicroscopy in gastric subepithelial lesions

BACKGROUND AND AIM

The effect of real-time analysis of needle-based confocal laser endomicroscopy (nCLE) for gastric subepithelial lesions (SELs) on the diagnostic value is unclear. The study aimed to investigate the diagnostic efficacy of real-time nCLE for gastric SELs and to assess the technical aspects and safety of real-time nCLE.

METHODS

Consecutive patients with gastric SELs ≥ 1 cm were prospectively investigated by endoscopic ultrasound (EUS), followed by nCLE. During EUS-nCLE, real-time nCLE diagnosis was made by an expert endoscopist. The procedure-relative adverse events were assessed and recorded. One-month washout period later, nCLE videos were reviewed off-line by the same endoscopist. The nCLE diagnoses were compared with corresponding pathological results. Additionally, image quality and interobserver agreements for the criteria were evaluated by three experienced endomicroscopists.

RESULTS

Except for one failing to be punctured, 60 patients completed EUS-nCLE procedures successfully. Real-time nCLE had high diagnostic accuracies of ≥ 88.3% for gastric SELs. There were no significant differences between real-time and off-line nCLE diagnoses for gastric SELs (P > 0.05). The overall accuracy of real-time nCLE for diagnosis of gastric SELs was 86.7%. There were no procedure-relative adverse events occurred. In addition, the mean image quality score was 3.6 (1 = poor and 5 = excellent). The interobserver agreement was "almost perfect" for ectopic pancreas and "substantial" for gastrointestinal stromal tumor, leiomyoma, and carcinoma.

CONCLUSIONS

Endoscopic ultrasound-nCLE could provide in vivo real-time diagnostic imaging with a high diagnostic accuracy. Meanwhile, real-time nCLE was feasible and had a satisfactory safety profile.

EUS-guided 22-gauge fine needle biopsy versus single-incision with needle knife for the diagnosis of upper gastrointestinal subepithelial lesions: a randomized controlled trial

Background and study aims  EUS-FNA has suboptimal accuracy in diagnosing gastrointestinal subepithelial tumors (SETs). EUS-guided 22-gauge fine needle biopsy (EUS-FNB) and single-incision with needle knife (SINK) were proposed to increase accuracy of diagnosis. This study aimed to prospectively compare the diagnostic accuracy and safety of EUS-FNB with SINK in patients with upper gastrointestinal SETs. Patients and methods  All adult patients referred for EUS evaluation of upper gastrointestinal SETs ≥ 15 mm in size were eligible for inclusion. Patients were randomized to undergo EUS-FNB or SINK. Lesions were sampled with a 22-gauge reverse beveled core needle in the EUS-FNB group and by a conventional needle-knife sphincterotome and biopsy forceps in the SINK group. Patients were blinded to the technique used. The primary outcome was diagnostic accuracy. Secondary outcomes included adverse events, histological yield and procedure duration. Study enrollment was terminated early due to poor recruitment. Results  A total of 56 patients (31 male (55.37 %); mean age, 67.41 ± 12.70 years) were randomized to either EUS-FNB (n = 26) or SINK (n = 30). Technical success was 96.15 % and 96.66 %, respectively. The majority of lesions were gastrointestinal stromal tumors (51.78 %). No significant difference was found between EUS-FNB and SINK in terms of diagnostic accuracy for a malignant or benign disease (76 % vs. 89.28 %, respectively; P  = 0.278). The rate of adverse events (none severe) was also comparable (7.69 % vs. 10 %, respectively; P =  1.0) including two abdominal pain episodes in the EUS-FNB group compared to two delayed bleeding (one requiring hospitalization and radiologic embolization) and 1 abdominal pain in the SINK group. Conclusion  EUS-FNB and SINK are equally effective techniques for upper gastrointestinal SETs sampling. SINK can be associated with mild to moderate delayed bleeding.

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.

Utility of EUS elastography in the diagnosis of gastric subepithelial tumors: a pilot study (with video)

BACKGROUND AND AIMS

EUS elastography is a real-time imaging technique that analyzes tissue elasticity. The aim of this study was to investigate the applicability of quantitative EUS elastography in the differential diagnosis of gastric subepithelial tumors (SETs).

METHODS

We prospectively registered 41 consecutive patients with gastric SETs and measured their strain ratios with EUS elastography. The strain ratios of gastric SETs were compared with the histopathologic diagnosis.

RESULTS

Thirty-one patients (mean age, 51.4 ± 12.6 years) were included in the analysis. The mean size of the SETs was 2.3 ± 0.7 cm. Lipomas had the lowest strain ratio of 1.6 (1.1-2.0), followed by leiomyomas 6.0 (2.0-29.0), ectopic pancreas 11.8 (1.7-29.3), gastrointestinal stromal tumors (GISTs) 51.1 (29.0-67.0), and schwannomas 62.0. With a cut-off value of 22.7, EUS elastography could differentiate GISTs from leiomyomas with sensitivity and specificity of 100% and 94.1%, respectively (P = .001; 95% confidence interval, 0.979-1.000).

CONCLUSIONS

EUS elastography could be a promising diagnostic adjunct for the assessment of gastric SETs, especially in differentiating GISTs from leiomyomas.

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration: A single-center analysis

Background: Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has become an important modality for identification of intra-abdominal masses. This study analyzed the accuracy of EUS-FNAB in a single medical center and explored factors related to positive diagnosis. Materials and methods: In total, 77 patients with EUS-FNAB were retrospectively reviewed from July 2016 to February 2020. "Atypical (tends to be neoplasm/malignancy)," "suspicious (first consider neoplasm/malignancy)," and "malignant" were defined as positive cytology. The final diagnoses were based on histopathologic examination. The positive rate of EUS-FNAB for the diagnosis of neoplasm and its associations with age, sex, target puncture mass size, liver function, tumor markers, albumin, hypertension, and diabetes were examined. Results: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in all patients were 77.9% (60/77), 76.1% (54/71), 100%, 100%, and 26.1% (6/23), respectively. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in the pancreas were 80.0% (48/60), 79.3% (46/58), 100%, 100%, and 14.3% (2/14), respectively. The results of EUS-FNAB in pancreatic masses showed that the level of CA19-9 was higher in the true positive group than in the false-negative group (p<0.05). There were no factors associated with the true positive cytologic diagnoses (p>0.05). Conclusions: Our single-medical center study showed that EUS-FNAB is an accurate diagnostic procedure for the evaluation of intra-abdominal masses. Further follow-up is required to explore factors associated with the true positive cytology.

A rare case of incidental finding of GIST during sleeve gastrectomy: Case report

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) is the term used to describe rare stromal neoplasms that are located in the gastrointestinal tract, it most commonly arises in the stomach. GIST is usually asymptomatic and discovered incidentally by Computed Tomography (CT) or Endoscopy.

PRESENTATION OF CASE

We report a case of incidental finding of GIST during Sleeve gastrectomy in a 56 year-old female that presented with a complaint of sever obesity and articular pain in lower limbs. The tumor was not compromising the performance of a save vertical gastric resection, so the resection was done and a mass specimen was sent for pathological examination that confirmed Gist with a low grade of malignancy.

DISCUSSION AND CONCLUSION

As a conclusion, we recommend keeping in mind incidental finding of GIST during abdominal surgeries and especially Sleeve gastrectomy, in order to detect this tumor as earlier as possible and have a good prognosis with a low chance for recurrence.

Snare-assisted endoscopic resection of gastric subepithelial tumors originating from the muscularis propria layer: a multicenter study

BACKGROUND AND AIM

Although successful endoscopic resection of gastric subepithelial tumors (SETs) originating from the muscularis propria (MP) layer has been frequently reported, it requires a relatively complicated technique and has a high perforation rate. In this retrospective study, we evaluated the efficacy and safety of the snare-assisted endoscopic resection (SAER) method which is performed using a snare and insulated-tip (IT) knife via a single-channel endoscope to reduce the perforation rate.

METHODS

In this study, fifty-six patients with gastric SETs originating from the MP layer treated by the SAER method at three institutions between July 2017 and December 2017 were reviewed. The procedure involved multiple steps as shown in Fig. 2. Data were obtained on demographics, SET features, histopathological diagnoses, procedure time, en bloc resection rate, R0 resection (negative margins) status, and adverse events.

RESULTS

Endoscopic resection was successfully performed in all patients. The median overall procedure time was 43.5 min (range 26-106 min). The mean size of resected specimens was 19.73 mm (range 10-33 mm). The overall rate of en bloc resection was 96.4% (54/56). In addition, the perforation rate was 7.1% (4/56), and defects in the stomach wall were very small and easily closed using metallic clips. No postprocedural bleeding occurred in any case.

CONCLUSIONS

The SAER method is an effective, safe, less costly technique for the removal of some gastric SETs originating from the MP layer with an appropriate size.

Efficacy and safety of endoscopic resection for small submucosal tumors originating from the muscularis propria layer in the gastric fundus

BACKGROUND

Gastric small submucosal tumors (SMTs) are becoming increasingly common. However, the fundus of stomach is regarded as a difficult area for endoscopic resection (ER). In this study, we investigated the efficacy, safety, and long-term outcomes of ER for small SMTs of the gastric fundus in a large series of patients, research that was previously lacking.

METHODS

537 consecutive patients with SMTs no more than 20 mm in diameter, occurring in the gastric fundus and originating from the muscularis propria layer, which were treated with endoscopic submucosal excavation or endoscopic full-thickness resection (EFTR) were included in this retrospective study at Zhongshan Hospital of Fudan University from January 2013 to September 2016. Clinicopathological, endoscopic, and follow-up data were collected and analyzed.

RESULTS

En bloc resection was achieved in 100% of patients, and complete resection was achieved for 530 (98.7%) lesions. Although the total rate of complications was 9.3%, few serious adverse events occurred in only three (0.6%) patients, including major pneumoperitoneum, major hydrothorax, and bleeding. Unlike lager tumor sizes and longer procedure times, endoscopist experience had a positive impact on decreasing the likelihood of complications. Based on statistical analysis, tumors with greater size near the cardia, which were treated by EFTR, were the significant contributors to longer operative times. A median follow-up of 32 months was available, and all patients were free from local recurrence or distant metastasis during the study period.

CONCLUSIONS

Although the gastric fundus presents technical difficulties, ER is effective for the resection of small gastric SMTs with a high complete resection rate and rare serious adverse events.

Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy in Gastrointestinal Subepithelial Tumors

The incidence of asymptomatic and incidentally found upper gastrointestinal subepithelial tumors (SETs) is increasing with the implementation of national cancer screening and the development of high-resolution endoscopy in Korea. However, endoscopy alone cannot be used to determine whether SETs are benign or malignant. Endoscopic ultrasound (EUS) is used to further characterize these lesions through the examination of their layered structure, internal echogenicity, size, and relationship to the extramural structure. These provide additional information on whether the lesion is benign or malignant. Nevertheless, the sensitivity and specificity of EUS alone in predicting malignancy is unsatisfactory. Recent guidelines have recommended deciding the timing of EUS-fine needle aspiration and biopsy (EUS-FNA/B) for SETs based on tumor size, malignant features on endoscopy, and high-risk features on EUS. The diagnostic accuracy of EUS-FNA/B is reportedly influenced by factors including needle size, number of needle passes, use of suction, use of a stylet in the needle assembly, fanning technique, availability of an on-site cytopathologist, and experience of the endosonographer. Therefore, according to the characteristics of the SETs, various subsequent methods and techniques should be appropriately employed to improve the diagnostic yield of EUS-FNA/B.

Fine-needle biopsy is superior to fine-needle aspiration of suspected gastrointestinal stromal tumors: a large multicenter study

Background and study aims  There are numerous studies published on the diagnostic yield of the new fine-needle biopsy (FNB) needles in pancreas masses. However, there are limited studies in suspected gastrointestinal stromal tumors (GIST lesions). The aim of this study was to evaluate the diagnostic yield of a new fork-tip FNB needle. Patients and methods  This was a multicenter retrospective study of consecutive patients from prospectively maintained databases comparing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) versus endoscopic ultrasound-guided FNB (EUS-FNB) using the fork-tip needle. Outcomes measured were cytopathology yield (ability to obtain tissue for analysis of cytology), ability to analyze the tissue for immunohistochemistry (IHC yield), and diagnostic yield (ability to provide a definitive diagnosis). Results  A total of 147 patients were included in the study of which 101 underwent EUS-FNB and 46 patients underwent EUS-FNA. Median lesion size in each group was similar (21 mm vs 25 mm, P  = 0.25). Cytopathology yield, IHC yield, and diagnostic yield were 92 % vs 46 % ( P  = 0.001), 89 % vs 41 % ( P  = 0.001), and 89 % vs 37 % ( P  = 0.001) between the FNB and FNA groups, respectively. Median number of passes was the same between the two groups at 3.5. Conclusion  EUS-FNB is superior to EUS-FNA for diagnostic yield of suspected GIST lesions. This should be confirmed with a prospective study.

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.

Efficacy of Mucosal Cutting Biopsy for the Histopathological Diagnosis of Gastric Submucosal Tumors

Background

Gastrointestinal stromal tumors occur frequently. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is performed commonly for diagnosis. However, the success rate of histological diagnosis is insufficient when the submucosal tumor (SMT) is small. Recently, another technique, mucosal cutting biopsy (MCB) has been reported. The aim of this study is to evaluate the efficacy and safety of MCB.

Method

Between January 2012 and August 2018, MCB and EUS-FNA were performed 16 and 31 times for diagnosing gastric SMT. The diagnostic rate, the rate of successful immunohistochemistry, and the safety were reviewed. Difficult locations for EUS-FNA were also evaluated.

Results

The mean SMT sizes measured on MCB and EUS-FNA were 21.2 and 36.2 mm. The diagnostic rates of MCB and EUS-FNA were almost the same (88 vs. 81%), but successful immunohistochemistry was significantly higher in the MCB group (93 vs. 59%, p = 0.03). In the subgroup of SMTs < 20 mm, the successful histological diagnosis rate from EUS-FNA was relatively low. There were no complications. Failures of EUS-FNA were more frequent in the middle third of the stomach.

Conclusions

MCB was an effective procedure for diagnosing gastric SMT, especially in the case of small SMTs located at the middle third of the stomach.

EUS-guided tissue sampling with a 20-gauge core biopsy needle for the characterization of gastrointestinal subepithelial lesions: A multicenter study

BACKGROUND AND OBJECTIVE

A new 20-gauge (G) biopsy needle with a core-trap technology has been developed with a large core size and enhanced flexibility. The aim of this multicenter study was to determine the feasibility, efficacy, and safety of EUS-guided fine-needle biopsy (EUS-FNB) with the new 20G needle in diagnosing subepithelial lesions (SELs).

MATERIALS AND METHODS

Retrospectively collected data from consecutive patients with SELs undergoing EUS-FNB with the 20G needle at five centers were analyzed.

RESULTS

A total of 50 SELs were included. The mean lesion size was 43.1 ± 17.5 mm. The lesion locations were esophagus (n = 1), stomach (n = 37), distal duodenum (n = 5), rectum (n = 6), and colon (n = 1). The procedure was technically feasible in all patients. Definitive diagnosis with full histological assessment including immunohistochemistry was obtained in 88% (44/50) of the patients. Considering malignant versus benign lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 85% (95% confidence interval [CI] 70.2-94.3), 100% (95% CI 58.7%-100%), 100% (95% CI 85.1%-100%), and 62.5 (95% CI 27.7-84.8), respectively. No major complications requiring additional care have been observed.

CONCLUSIONS

In this multicenter study, we found that EUS-FNB with the new 20G core needle is an effective and safe method for the diagnosis of SELs with a high rate of producing adequate histological material and high diagnostic accuracy even from difficult-to-approach anatomical locations.

Impact of endoscopic ultrasound-guided fine-needle biopsy on the diagnosis of subepithelial tumors: A propensity score-matching analysis

BACKGROUND AND AIM

Immunohistological evaluations are essential for diagnosing subepithelial tumors (SET). However, endoscopic ultrasound-guided sampling using fine-needle aspiration (FNA) needles is limited in its ability to procure core tissue for immunostaining. Fine-needle biopsy (FNB) needles may mitigate this limitation. The present study aimed to examine the efficacy of FNB needles for procuring samples that enable the diagnosis of SET.

METHODS

One hundred sixty patients were included in the study and separated into those whose samples were obtained using FNB needles (FNB group) and those whose samples were procured using FNA needles (FNA group). Groups were compared regarding the conclusive diagnosis rate and unwarranted resection rate. Propensity score matching was introduced to reduce selection bias.

RESULTS

Rates at which conclusive diagnoses were reached through adequate immunohistological evaluations were 82% and 60% in the FNB and FNA groups, respectively; this difference was significant (P = 0.013). Unwarranted resection rate was significantly lower in the FNB group (2%) than in the FNA group (14%; P = 0.032). Multivariate analyses showed that lesions ≤20 mm were a significant risk factor for lower conclusive diagnosis rates following the use of FNB needles (P = 0.017).

CONCLUSIONS

Fine-needle biopsy needles can be useful for obtaining samples that facilitate the diagnosis of SET and for avoiding unwarranted resections. However, FNB needles may be less advantageous for small SET.

Lesion size determines diagnostic yield of EUS-FNA with onsite cytopathologic evaluation for upper gastrointestinal subepithelial lesions

BACKGROUND/AIMS

The aim of this study was to determine the diagnostic yield and factors influencing the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for upper gastrointestinal (GI) subepithelial lesions (SELs) with rapid onsite cytopathologic evaluation.

MATERIALS AND METHODS

This is a single-center, retrospective study.

RESULTS

Among 22 patients who underwent EUS-FNA, a cytopathological diagnosis was reached in 16 (72.7%) patients. The EUS-FNA results were as follows: seven GISTs (31.8%), six leiomyomas (27.2%), four non-diagnostics (18%), two duplication cysts (9%), two spindle cell tumor (9%), and one ectopic pancreas (4.5%). The long-axis size was > 20 mm in 12 patients (average size: 31.3 ±9.3 mm) and < 20 mm (average size: 16.6 ±2.5 mm) in 10 patients. Diagnostic accuracy of EUS-FNA from lesions < 20 mm was 50% (5/10 lesions), and of lesions > 20 mm was 91.6% (11/12 lesions) (Fisher's exact test; p=0.028). Six patients underwent surgical resection. Surgical pathology results of five lesions (four GIST, one leiomyoma) were consistent with cytopathology results (83.3%).

CONCLUSION

The diagnostic yield of EUS-FNA of the upper GI SELs with an onsite cytopathologic interpretation was 72.7%. Lesion size < 2 cm significantly reduces the diagnostic yield of EUS-FNA for the upper GI SELs.

Endoscopic Enucleation Is Effective and Relatively Safe in Small Gastric Subepithelial Tumors Originating from Muscularis Propria

BACKGROUND

Gastric subepithelial tumors originating from muscularis propria (MP) are usually benign, but some have malignant potential.

AIMS

The aim of this study was to evaluate the utility of endoscopic enucleation for the diagnosis and treatment of MP tumors.

PATIENTS AND METHODS

From January 2010 to February 2018, eighty patients with gastric MP tumors underwent endoscopic enucleation at our hospital. Band ligation and resection (BLR) or endoscopic muscularis resection (EMD) was performed based on considerations of tumor size (≤ 12 mm or > 12 mm). Tumor characteristics, procedure times, complete resection rates, adverse events and recurrence were analyzed.

RESULTS

Eighty patients with 82 lesions were eligible for inclusion in this study. BLR was used to treat 41 lesions. For these lesions, mean tumor size was 9.5 mm, median procedural time was 17.6 min (range 4-52), and the endoscopic complete resection rate was 100% (41/41). Perforation was developed in four patients, and was closed by endoscopic clipping. EMD was used to treat 41 lesions. Median procedure time was 66.1 min (range 12-260) and the endoscopic complete resection rate was 85.4% (35/41). Perforation occurred in eight patients, four patients received endoscopic treatment and four underwent surgery. Tumor recurrence was not observed in any patient over follow-up (mean 26.3 months).

CONCLUSION

Endoscopic enucleation appears to offer an effective, relatively safe means for diagnosing and treating gastric subepithelial tumors originating from the MP, and BLR provides a straightforward, effective, and relatively safe treatment for small MP tumors (≤ 12 mm).

Characterization of subepithelial lesions of the stomach and esophagus by contrast-enhanced EUS: A retrospective study

Background and Objectives:

Subepithelial lesions (SELs) of the upper part of the digestive tract are rare, and it can be difficult to characterize them. Recently, contrast-enhanced endosonography (EUS) and elastometry have been reported as useful adjuncts to EUS and EUS-guided fine needle aspiration (EUS-FNA) in cases of pancreatic mass and lymph node involvement. The aim of this retrospective analysis was to evaluate whether contrast-enhanced EUS can discriminate benign submucosal lesions from malignant ones. We describe our retrospective experience using the contrast agent SonoVue^® (Bracco Imaging, Milan, Italy) in an attempt to increase the diagnostic yield.

Patients and Methods:

Between May 2011 and September 2014, 14 patients (5 men, 9 women; median age 64 years, range 31–80 years) with SELs of the stomach or esophagus underwent EUS with SonoVue^® (low mechanical index). There were 3 esophageal lesions and 11 gastric lesions. Mean size of the lesions was 30 mm (range 11–50 mm). They were discovered after anemia (n = 5), dysphagia (n = 1), and pain (n = 4) and during follow-up for resected gastrointestinal stromal tumors (GISTs) (n = 1) and a standard upper gastrointestinal endoscopy (n = 3). On endoscopic sonograms, 10 of these lesions were hypoechoic and located in the fourth layer (muscularis), and 4 were in the second or third layer (mucosa and submucosa). Contrast enhancement was assessed in the early phase (after several seconds) and late phase (>30 seconds); a final diagnosis was made based on the findings of EUS-FNA using a 19-gauge ProCore (Cook Medical, Bloomington, IN) (n = 9) or 22-gauge FNA system (Cook Medical) (n = 1), the resected specimen (n = 3), or deep biopsy (n = 1). Different immunostaining was used in the pathologic studies (RNA was analyzed later using the C-kit, CD-117, CD-34, desmin, DOG-1, α-smooth actin, caldesmon, PS-100, and Ki-67 antibodies).

Results:

Final diagnoses were leiomyoma (n = 4), GIST (n = 5), schwannoma (n = 1), inflammatory tumor of Helvig (n = 1), pancreas rest (n = 2), and fibrosis (n = 1). No complications occurred. All 5 GISTs showed enhancement in the early and late phases, whereas the 8 remaining lesions did not show any enhancement. Only 1 leiomyoma showed heterogeneous enhancement.

Limitations:

The monocentric and retrospective study design and small number of patients.

Conclusions:

In cases of SELs of the stomach or esophagus, SonoVue^® could be a complementary tool to endosonography to differentiate GISTs (early and clear enhancement) from other SELs (few or no enhancement), such as leiomyomas or pancreatic rest. These results are similar to those of the few, small studies published on this topic, but more studies with a larger number of patients are needed to confirm these findings.

Concise review on the comparative efficacy of endoscopic ultrasound-guided fine-needle aspiration vs core biopsy in pancreatic masses, upper and lower gastrointestinal submucosal tumors

Endoscopic ultrasound (EUS)-guided fine needle aspiration with or without biopsy (FNA/FNB) are the primary diagnostic tools for gastrointestinal submucosal tumors. EUS-guided fine needle aspiration (EUS-FNA) is considered a first line diagnostic method for the characterization of pancreatic and upper gastrointestinal lesions, since it allows for the direct visualization of the collection of specimens for cytopathologic analysis. EUS-FNA is most effective and accurate when immediate cytologic assessment is permitted by the presence of a cytopathologist on site. Unfortunately, the accuracy and thus the diagnostic yield of collected specimens suffer without this immediate analysis. Recently, a EUS-FNB needle capable of obtaining core samples (fine needle biopsy, FNB) has been developed and has shown promising results. This new tool adds a new dimension to the diagnostic and therapeutic utility of this technique. The aim of the present review is to compare the efficacy of EUS-FNA to that afforded by EUS-FNB in the characterization of pancreatic masses and of upper and lower gastrointestinal submucosal tumors.

A Novel Method of Diagnosing Aberrant Pancreas: Needle-based Confocal Laser Endomicroscopy

Aberrant pancreas is defined as pancreatic tissue present outside of the pancreas and is often found incidentally during esophagogastroduodenoscopy. Obtaining sufficient tissue to differentiate aberrant pancreas from other subepithelial lesions is sometimes difficult. Due to the lack of a definitive diagnosis, patients often undergo unnecessary surgery. We herein report the first case of aberrant pancreas in which the concomitant use of needle-based probe confocal laser endomicroscopy and fine-needle aspiration supported the final diagnosis. Needle-based probe confocal laser endomicroscopy provides a real-time in vivo histopathology evaluation and may be a feasible means of diagnosing aberrant pancreas.

Diagnostic ability of a 22G Franseen needle in endoscopic ultrasound-guided fine needle aspiration of subepithelial lesions

The differential diagnosis of gastrointestinal subepithelial lesions (SELs) such as gastrointestinal stromal tumors from other benign tumors is important. In the present study, adequate sample rates of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with a 22G Franseen needle for SELs were evaluated. The present study included 57 consecutive lesions (61 sessions) of EUS-FNA using a 22G needle to evaluate SELs between July 2013 and October 2017. Adequate sample rates were compared retrospectively between a 22G conventional needle group (C group) and a 22G Franseen needle group (F group). The overall adequate sample rate was 80.3%. The adequate sample rates in the C and F groups were 75.0% (33/44) and 94.1% (16/17), respectively (P=0.15). For lesions ≥20 mm, the adequate sample rates were 82.8% (24/29) in the C group and 91.7% (11/12) in the F group, 8.9% higher in the F group. However, for lesions <20 mm, the adequate sample rates were 60% (9/15) in the C group and 100% (5/5) in the F group, 40% higher in the F group (P=0.65, 0.26). In conclusion, the results of the present study suggested that using a 22G Franseen needle for EUS-FNA evaluation of SELs may improve adequate sample rates in small lesions <20 mm in diameter.

Current clinical management of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common malignant subepithelial lesions (SELs) of the gastrointestinal tract. They originate from the interstitial cells of Cajal located within the muscle layer and are characterized by over-expression of the tyrosine kinase receptor KIT. Pathologically, diagnosis of a GIST relies on morphology and immunohistochemistry [KIT and/or discovered on gastrointestinal stromal tumor 1 (DOG1) is generally positive]. The prognosis of this disease is associated with the tumor size and mitotic index. The standard treatment of a GIST without metastasis is surgical resection. A GIST with metastasis is usually only treated by tyrosine kinase inhibitors without radical cure; thus, early diagnosis is the only way to improve its prognosis. However, a GIST is usually detected as a SEL during endoscopy, and many benign and malignant conditions may manifest as SELs. Conventional endoscopic biopsy is difficult for tumors without ulceration. Most SELs have therefore been managed without a histological diagnosis. However, a favorable prognosis of a GIST is associated with early histological diagnosis and R0 resection. Endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (EUS-FNA) are critical for an accurate diagnosis of SELs. EUS-FNA is safe and effective in enabling an early histological diagnosis and adequate treatment. This review outlines the current evidence for the diagnosis and management of GISTs, with an emphasis on early management of small SELs.

EUS-guided sampling with 25G biopsy needle as a rescue strategy for diagnosis of small subepithelial lesions of the upper gastrointestinal tract

BACKGROUND AND STUDY AIMS

 This study was designed to evaluate the impact of additional tissue obtained with endoscopic ultrasound (EUS)-guided 25-gauge core biopsy needle (25G-PC) following an unsuccessful fine-needle biopsy (FNB) performed with larger-bore needles for the characterization of gastrointestinal subepithelial lesions (GI-SELs).

PATIENTS AND METHODS

 We prospectively collected and retrospectively analyzed information in our database from January 2013 to June 2017 for all patients with GI-SELs who received a EUS-guided FNB (EUS-FNB) with 25G-PC during the same procedure after failure of biopsy performed with larger-bore needle. Diagnostic yield, diagnostic accuracy and procedural complications were evaluated.

RESULTS

Sixteen patients were included in this study, 10 men and 6 women, median age 67.8 (range 43 to 76 years). Five patients were found to have a SEL localized in the distal duodenum, five in the gastric antrum, two in the gastric fundus and four in the gastric body. The mean size of the lesions was 20.5 mm (range 18 - 24 mm). EUS-FNB with 25G-PC enabled final diagnosis in nine patients (56.2 %). Regarding the subgroup of duodenal lesions, the procedure was successful in four of five (80 %). Final diagnoses with EUS-guided sampling were GIST (n = 6), leiomyoma (n = 2) and metastatic ovarian carcinoma (n = 1). No procedure-related complications were recorded.

CONCLUSION

 In patients with small GI-SELs, additional tissue obtained with 25G-PC could represents a "rescue" strategy after an unsuccessful procedure with larger-bore needles, especially when lesions are localized in the distal duodenum.

Leiomyosarcoma of the stomach treated by endoscopic submucosal dissection

There have been no reports of primary leiomyosarcoma of the stomach treated by endoscopic submucosal dissection (ESD). We report an extremely rare case of gastric leiomyosarcoma that was successfully treated by ESD. An asymptomatic 74-year-old female underwent esophagogastroduodenoscopy for screening in December 2013. A centrally depressed submucosal tumor 10 mm in diameter was detected at the posterior wall of the upper gastric body. Follow-up esophagogastroduodenoscopy conducted 5 months later showed that the tumor diameter had increased to 15 mm. Endoscopic ultrasound revealed a hypoechoic mass located in the second to the middle of the third layer. Endoscopic ultrasound-guided fine-needle aspiration demonstrated a myogenic tumor. The tumor was completely resected by ESD without complications. Immunohistopathological diagnosis of the resected specimen was gastric leiomyosarcoma derived from the muscularis mucosae, with negative lateral and vertical margins. No local recurrence or metastasis has been detected at 36 months after ESD. This is the first report of gastric leiomyosarcoma treated by ESD in the English language literature.

Case Report of a Small Gastric Neuroendocrine Tumor in a Deep Layer of Submucosa With Diagnosis by Endoscopic Ultrasound-Guided Fine-Needle Aspiration and Treatment With Laparoscopic and Endoscopic Cooperative Surgery

Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by enterochromaffin-like cells of the stomach. Optimal management of GNETs has not yet been definitively determined. Endoscopic resection is approximately recommended for small GNETs associated with hypergastrinemia. However, endoscopic resection might present risk of perforation or positive vertical margin because neuroendocrine tumors occur in the deep mucosa, with some invading the submucosa. In this case, a patient with type A chronic atrophic gastritis had a small subepithelial lesion in a deep submucosal layer, and we diagnosed it as GNET using endoscopic ultrasound-guided fine-needle aspiration biopsy using a forward-viewing and curved linear-array echoendoscope. Moreover, our results show that laparoscopic and endoscopic cooperative surgery with regional lymph node dissection is a safe and feasible procedure for GNETs, especially those that cross to the muscularis propria. We suggest this approach as one therapeutic option for GNETs because it safely minimizes resection and is less invasive.

Direct endoscopic biopsy for subepithelial tumor larger than 20 mm after removal of overlying mucosa

OBJECTIVE

An accurate diagnosis of a subepithelial tumor (SET) using endoscopic ultrasound (EUS) without tissue acquisition is difficult. Treatment plan for a SET may be influenced by endoscopic tissue diagnosis. We aimed to clarify the clinical outcomes of direct endoscopic biopsy for SET after removal of the overlying mucosa.

METHODS

We evaluated the medical records of 15 patients. All patients underwent direct endoscopic biopsy for a SET larger than 20 mm (involving proper muscle layer) after removal of the overlying mucosa. The rate of achieving an accurate diagnosis and the treatment decision after the procedure were evaluated.

RESULTS

The patients' mean age was 55.1 ± 14.7 years. The patient population predominantly comprised men (9/15, 60%). The mean tumor size was 24.3 ± 7.8 mm. The mean biopsy number was 3.5 ± 1.7. No major complications occurred with the procedure. The mean procedure time was 15 ± 7.4 min. An accurate diagnosis was achieved in 93.3% of patients (14/15). The main pathological diagnoses after direct endoscopic SET biopsy were leiomyoma (33.3%, 5/15) and ectopic pancreas (33.3%, 5/15) followed by gastrointestinal stromal tumor (GIST) (13.3%, 2/15) and schwannoma (13.3%, 2/15). The treatment plan was influenced by the result of biopsy in 80% of patients (9/15), and unnecessary surgical resection was avoided.

CONCLUSIONS

Direct endoscopic SET biopsy after removal of the overlying mucosa using an endoscopic conventional snare was a useful diagnostic tool with high diagnostic accuracy and low risk of complications.

A novel grasp-and-loop closure method for defect closure after endoscopic full-thickness resection (with video)

BACKGROUND

Endoscopic full-thickness resection (EFTR) is a minimally invasive method for en bloc resection of gastrointestinal (GI) lesions originating from the muscularis propria layer. Successful closure of the wall defect is a critical step.

OBJECTIVE

The aim of this study was to evaluate the feasibility and efficacy of a novel and simplified endoscopic grasp-and-loop (GAL) closure method using an endo-loop assisted with grasping forceps for defect closure.

METHODS

From January 2015 to March 2016, 13 patients with submucosal tumors (SMTs) originating from the muscularis propria (MP) layer underwent EFTR and were enrolled in this study. After successful tumor resection, an endo-loop was anchored onto the circumferential margin of the gastric defect with grasping forceps assistance and tightened gently. Patient characteristics, tumor size, en bloc resection, and postoperative complications were evaluated.

RESULTS

Of the 13 lesions in the stomach, two were located in the greater curvature of the mid-upper body, 11 were located in the fundus. The endoscopic GAL closure method was successfully performed after EFTR in all the 13 patients without laparoscopic assistance. The mean procedure time was 43.5 min (range 20-80 min), while the GAL closure procedure took a mean of 9.4 min (range 3-18 min). The mean resected lesion size was 1.5 cm (range 0.5-3.5 cm). Pathological diagnoses of these lesions were 11 gastrointestinal stromal tumors (GISTs) and two leiomyomas. No major adverse events occurred during or after the procedure. All the patients were discharged after a mean time of 2.4 days (range 1-4 days). No residual lesion or tumor recurrence was found during the follow-up period (median, 5 months; range, 1-15 months).

CONCLUSIONS

The endoscopic GAL closure method is feasible, effective, and safe for closing the gastric defect after EFTR in patients.

Pancreatic Gastrointestinal Stromal Tumor: Clinicopathologic Features and Prognosis

GOALS

The present study aimed to investigate the clinicopathologic features and prognosis of pancreatic gastrointestinal stromal tumor (GIST).

BACKGROUND

Reports on clinicopathologic features and prognosis of pancreatic GIST are limited due to the extremely rare incidence.

STUDY

One case of pancreatic GIST from our center and 44 cases reported in MEDLINE were enrolled in this study. Clinicopathologic features and prognosis of pancreatic GISTs were analyzed and compared with 297 gastric GISTs from our center.

RESULTS

The most common location was head of pancreas (38.5%). The majority of pancreatic GISTs exceeded 5 cm (74.4%), displayed cystic or mixed imaging features (56.4%), and were high risk (85.7%). The 5-year disease-free survival (DFS) and disease-specific survival rates were 66.1% and 95.8%, respectively. Mitotic index was the only risk factor for DFS of pancreatic GISTs. The distribution of tumor size, histologic type and National Institutes of Health risk category were significantly different between pancreatic and gastric GISTs. The 5-year DFS rate of pancreatic GISTs was significantly lower than that of gastric GISTs. Multivariate analysis showed that location was an independent prognostic factor for DFS between pancreatic and gastric GISTs.

CONCLUSIONS

The most common location was head of pancreas. The majority of pancreatic GISTs were large and highly malignant. Pancreatic GISTs differed significantly from gastric GISTs in respect to clinicopathologic features. The DFS of pancreatic GISTs was worse than that of gastric GISTs.

Comparison of FNA and fine-needle biopsy for EUS-guided sampling of suspected GI stromal tumors

BACKGROUND AND AIMS

Subepithelial lesions are found in about 1% of all EGD procedures, and GI stromal tumors are a type of subepithelial lesion commonly encountered. Although the majority of subepithelial lesions are benign, GI stromal tumors have malignant potential, making a definitive diagnosis important. Currently, the criterion standard for the diagnosis of GI stromal tumors is EUS-directed FNA (EUS-FNA). The definitive diagnosis of GI stromal tumors relies on immunohistochemical staining, which depends on enough tissue being submitted to the pathologist. Achieving adequate tissue acquisition from suspected GI stromal tumors by EUS-FNA remains a limitation. Advancements in needle design, however, have improved tissue acquisition and therefore may improve the definitive diagnosis of GI stromal tumors by EUS-FNA. The goal of this study is to compare a fine-needle biopsy (FNB) needle (SharkCore, Medtronics) with FNA needles in definitively diagnosing suspected GI stromal tumors.

METHODS

This is a retrospective, single-center study of consecutive patients with suspected GI stromal tumors by EUS characterization who underwent EUS-FNA or EUS-FNB.

RESULTS

A total of 106 patients (53 men, mean [± standard deviation {SD}] age 62.19 ± 16.33 years) were included in the study undergoing EUS-FNA or EUS-FNB of suspected GI stromal tumors. The needle size that was used most often was 22 gauge in both groups. The average size of the lesions was 27.68 ± 15.70 mm; 71.7% of lesions were located in stomach, 19.8% in the esophagus, 5.7% in the duodenum, and 2.8% in the rectosigmoid colon. Ninety-one patients underwent EUS-FNA and 15 patients underwent EUS-FNB. Adequate tissue was procured, allowing immunohistochemical staining in 59 (64.8%) patients in the FNA group and 15 (100%) patients in the FNB group; P = .006. A diagnosis was reached by immunohistochemical staining in 48 (52.7%) patients in the FNA group and 13 (86.7%) patients in the FNB group; P = .01. Tissue was insufficient to make a cytologic diagnosis in 22 (24.2%) patients in the FNA group compared with none in the FNB group; P = .03. Adequate tissue was procured on the first pass of the FNB needle in the majority of patients (83.3%), whereas only 23.5% of patients had adequate tissue on the first pass by the FNA needle, with a median of 3 passes; P = .00. Tissue was insufficient to perform immunohistochemical staining, and thus a diagnosis could not be confirmed before surgery in 8 of the 34 surgical patients in the FNA group. Ten of 15 patients in the EUS-FNB group underwent surgery, all of whom were correctly diagnosed by FNB. There were no reported immediate adverse events or technical difficulties in either group.

CONCLUSIONS

EUS-FNB by using a SharkCore needle for suspected GI stromal tumors is technically similar and equally safe as FNA, with better tissue acquisition, which was achieved with fewer needle passes and an improved diagnostic yield by immunohistochemical staining.

High clinical impact and diagnostic accuracy of EUS-guided biopsy sampling of subepithelial lesions: a prospective, comparative study

Background

In a tertiary center setting we aimed to study the diagnostic accuracy and clinical impact of EUS-guided biopsy sampling (EUS-FNB) with a reverse bevel needle compared with that of fine needle aspiration (EUS-FNA) in the work-up of subepithelial lesions (SEL).

Methods

All patients presenting with SELs referred for EUS-guided sampling were prospectively included in 2012–2015. After randomization of the first pass modality, dual sampling with both EUS-FNB and EUS-FNA was performed in each lesion. Outcome measures in an intention-to-diagnose analysis were the diagnostic accuracy, technical failures, and adverse events. The clinical impact was measured as the performance of additional diagnostic procedures post-EUS and the rate of unwarranted resections compared with a reference cohort of SELs sampled in the same institution 2006–2011.

Results

In 70 dual sampling procedures of unique lesions (size: 6–220 mm) the diagnostic sensitivity for malignancy and the overall accuracy of EUS-FNB was superior to EUS-FNA compared head-to-head (90 vs 52%, and 83 vs 49%, both p < 0.001). The adverse event rate of EUS-FNB was low (1.2%). EUS-FNB in 2012–2015 had a positive clinical impact in comparison with the reference cohort demonstrated by less cases referred for an additional diagnostic procedure, 12/83 (14%) vs 39/73 (53%), p < 0.001, and fewer unwarranted resections in cases subjected to surgery, 3/48 (6%) vs 12/35 (34%), p = 0.001.

Conclusions

EUS-FNB with a reverse bevel needle is safe and superior to EUS-FNA in providing a conclusive diagnosis of subepithelial lesions. This biopsy sampling approach facilitates a rational clinical management and accurate treatment.

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-017-5808-2) contains supplementary material, which is available to authorized users.

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.

Endoscopic ultrasound with tissue sampling is accurate in the diagnosis and subclassification of gastrointestinal spindle cell neoplasms

BACKGROUND AND OBJECTIVES

Mesenchymal (spindle cell) neoplasms (SCN) of the gastrointestinal (GI) tract are an important subtype of subepithelial lesions that need subclassification to assess their malignant potential. Reported success rates of accurate subclassification with endoscopic ultrasound (EUS)-guided biopsies are variable. Our goal was to analyze our experience using EUS-guided TruCut biopsy (EUS-TCB) in the majority of patients.

METHODS

Retrospective analysis in patients who underwent EUS with biopsies for suspected SCN at our tertiary referral center between 2004 and 2013.

RESULTS

A total of 146 patients with suspected SCN underwent EUS with tissue acquisition. Thirteen patients were excluded from analysis because tissue acquisition established a definite diagnosis other than SCN. In the remaining 133 patients, tissue acquisition was diagnostic of SCN in 118 (88.7%) and nondiagnostic in 15 (11.3%). Subclassification based on immunohistochemistry (IHC) was possible in 109 of the 133 cases (81.9%). The final diagnosis was GI stromal tumor in 64, leiomyoma in 39, and schwannoma in 6 cases. The percentage of patients who were subclassified by the various EUS-guided techniques together was 72.18%, and the percentage of patients who were subclassified specifically with EUS-TCB was 61.65%. Tissue specimens that enabled a specific diagnosis based on histological or cytological characteristics in conjunctions with IHC were obtained with EUS core biopsy in 83 (TCB in 82 and ProCore needle biopsy in 1), fine-needle aspiration in 13, mucosal resection in 10, and forceps biopsies (bite-on-bite) in 3 cases.

CONCLUSION

EUS with endoscopic tissue acquisition is accurate in the diagnosis and subclassification of SCN. In experienced hands, the EUS-TruCut needle is a valuable tool with a high success rate for this indication.

Endoscopic ultrasound-guided tissue sampling of small subepithelial tumors of the upper gastrointestinal tract with a 22-gauge core biopsy needle

Background and study aims The optimal approach to small subepithelial tumors (SETs) of the upper gastrointestinal tract remains inconclusive. The aim of this study was to evaluate endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for less invasive tissue sampling of small SETs of the upper gastrointestinal tract. Patients and methods In this prospective observational study patients with small ( ≤ 3 cm) SETs of the upper gastrointestinal tract were eligible and underwent EUS-FNB with a 22-gauge core biopsy needle. The main outcome measure was the diagnostic yield. The number of obtained core biopsies was also assessed. Results Twenty patients were included. The mean SET size was 16 mm (range 10 - 27 mm). EUS-FNB was technically feasible in all cases and no complications were observed. The diagnostic yield was 75 %. Core biopsy specimens were obtained in only 25 % of cases. Conclusion EUS-FNB with a 22-gauge core biopsy needle of small SETs can achieve a definite diagnosis in the majority of cases. However, because core samples cannot regularly be obtained, EUS-FNB seems not to be convincingly superior to standard EUS-FNA in this setting.

Rapid On-Site Evaluation by Endosonographers during Endoscopic Ultrasonography-Guided Fine-Needle Aspiration for Diagnosis of Gastrointestinal Stromal Tumors

BACKGROUND/AIMS

Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been used to diagnose gastrointestinal submucosal tumors (SMTs). Although rapid on-site evaluation (ROSE) has been reported to improve the diagnostic accuracy of EUS-FNA for pancreatic lesions, on-site cytopathologists are not routinely available. Given this background, the usefulness of ROSE by endosonographers themselves for pancreatic tumors has also been reported. However, ROSE by endosonographers for diagnosis of SMT has not been reported. The aim of this study was to evaluate the diagnostic accuracy of EUS-FNA with ROSE by endosonographers for SMT, focusing on diagnosis of gastrointestinal stromal tumor (GIST), compared with that of EUS-FNA alone.

METHODS

Twenty-two consecutive patients who underwent EUS-FNA with ROSE by endosonographers for SMT followed by surgical resection were identified. Ten historical control subjects who underwent EUS-FNA without ROSE were used for comparison.

RESULTS

The overall diagnostic accuracy for SMT was significantly higher in cases with than without ROSE (100% vs. 80%, p=0.03). The number of needle passes by FNA with ROSE by endosonographers tended to be fewer, although accuracy was increased (3.3±1.3 vs. 5.9±3.8, p=0.06).

CONCLUSIONS

ROSE by endosonographers during EUS-FNA for SMT is useful for definitive diagnosis, particularly for GIST.

The cut-off value of tumor size and appropriate timing of follow-up for management of minimal EUS-suspected gastric gastrointestinal stromal tumors

Backgroud

The detectable rate of minimal gastric GISTs has continuously increased. While the surveillance and management of GIST <2 cm have been deemed controversial or lack evidence-based approaches.  The aim of the current study is to propose a cut-off value of tumor size for treatment policy and the appropriate timing for endoscopic ultrasonography (EUS) follow-up in the minimal EUS-suspected gastric GIST patients.

Methods

A single-institution retrospective study was performed. 69 patients with EUS-suspected gastric GISTs were studied from November 2008 to March 2015. 69 patients with minimal gastric GISTs ≤2 cm diagnosed by EUS were followed for a mean period of 29 months (range, 12 to 70). An at least 20% increase of the maximal diameter of the tumors was set as a significant change.

Results

During follow-up, Of the 69 minimal EUS-suspected GISTs, 16 (23.2%) showed significant changes in size. 11 out of 69 GISTs (15.9%), 6 out of 43 GISTs (14.0%), 7 out of 30 GISTs (23.3%) showed significant changes in size, at 1 year, 2 years, and more than 3 years respectively. The receiver operating characteristic curve analysis showed that the tumor size cut-off was 9.5 mm. Only 4.7 and 3.7% of gastric EUS-suspected GISTs of <9.5 mm in size showed significant changes at 1 year and 2 years, while 9.5% at more than 3 years. 34.6, 31.3 and 55.6% of gastric EUS-suspected GISTs of ≥ 9.5 mm in size showed significant changes at 1 year, 2 years and more than 3 years.

Conclusions

Minimal EUS-suspected GISTs, larger than 9.5 mm may be associated with significant progression. The patients with a ≥ 9.5 mm GIST should have a EUS 6–12months, while <9.5 mm GIST may have a EUS extended to every 2–3 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0567-4) contains supplementary material, which is available to authorized users.

Contrast-enhanced (endoscopic) ultrasound and endoscopic ultrasound elastography in gastrointestinal stromal tumors

Background and Objectives:

Gastrointestinal stromal tumors (GISTs) represent the largest group of subepithelial tumors (SET) of the upper gastrointestinal (GI) tract. They may show malignant behavior, in contrast to other SET. Endoscopic ultrasound (EUS) is frequently used to characterize SET. With the introduction of contrast-enhanced ultrasound (CEUS) into EUS (CE-EUS), distinct enhancement patterns can be detected. In the presented study, the characteristic features of CE-EUS in GIST are analyzed and compared with those of other SET.

Materials and Methods:

Consecutive patients from four centers with SET of the upper and middle GI tract were included and received endoscopic or transcutaneous CEUS. The results were compared with EUS-guided tissue acquisition, forceps biopsy, or surgical resection.

Results:

Forty-two out of 62 (68%) patients had SET of the stomach, 17/62 (27%) of the small intestine, 2/62 (3%) of the esophagus, and 1/62 (2%) extraintestinal. Eighty-one percent underwent surgery. Leiomyoma was found in 5/62 (8%) and GIST in 57/62 patients (92%). Thirty-nine out of 57 (68%) patients had GIST lesions in the stomach, 17/57 (30%) had GIST of the small intestine, and 1/57 (2%) patients had extraintestinal GISTs. GIST size was 62.6 ± 42.1 (16–200) mm. Hyperenhancement had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 100%, 100%, 93%, and 98% for the diagnosis of GIST. Fifty out of 57 patients with GIST (88%) showed avascular areas in the center of the lesions.

Conclusion:

CE-EUS and CEUS show hyperenhancement and avascular areas in a high percentage of GIST but not in leiomyoma. Thus, GIST and leiomyoma can be discriminated accurately.

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.

EUS-guided 22-gauge fine needle biopsy for the diagnosis of gastric subepithelial tumors larger than 2 cm

OBJECTIVE

EUS-guided fine needle biopsy (EUS-FNB) was introduced to obtain tissue cores. However, data on the efficacy of EUS-FNB for the diagnosis of gastric subepithelial tumors (SET) are limited. This study was aimed to determine the tissue acquisition and diagnostic yield of EUS-FNB using a novel 22-gauge FNB needle.

MATERIAL AND METHODS

Between May 2012 and February 2014, we retrieved data on 78 consecutive patients who underwent 22-gauge EUS-FNB for tissue sampling of gastric SET larger than 2 cm. Relevant tumor and EUS-related parameters were reviewed retrospectively.

RESULTS

The median tumor diameter was 2.8 cm and tumors were punctured successfully in 77 SET (98.7%). EUS-FNB was diagnostic in 81.8% of SET (63/77), by obtaining core biopsy tissue in 96.8% (61/63) and aspirates in 27.0% (17/63). FNB specimens permitted immunostaining for the diagnosis of gastrointestinal stromal tumors (GIST) in 30 SET (47.6%), 20 leiomyomas (31.7%), and 3 schwannomas (4.8%). Diagnoses could be made without immunostaining in 10 SET (15.9%). Tissue adequacy was optimal in 85.7% of FNB specimens by endosonographers' on-site visual evaluation. Endosonographers' evaluation of tissue adequacy was the only factor significantly associated with a higher diagnostic yield in univariate analysis. No adequate high-power fields for GIST risk stratification were available in FNB specimens. There was a single case of post-procedural bleeding (1.3%).

CONCLUSION

EUS-FNB using 22-gauge needle obtains a high yield for the diagnosis of gastric SET ≥2 cm, mostly via core tissue acquisition. Endosonographers should pay careful attention to the adequacy of FNB specimens.

Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors

The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730).