Endoscopic ultrasound-guided Trucut biopsy of gastrointestinal mesenchymal tumor

The maximum transverse diameter: an effective indicator for predicting peroral en bloc retrieval rate of mesenchymal tumors after endoscopic resection

BACKGROUND

Gastrointestinal mesenchymal tumors (GIMTs) are being increasingly resected under endoscopy. Large GIMTs cannot be completely retrieved through the mouth, but the cut-off diameter of peroral en bloc retrieval (PEBR) for GIMTs completely resected is still unknown. This study aimed to investigate the ability of maximum transverse diameter (MTD) to predict the PEBR rate of GIMTs after endoscopic resection (ER).

METHODS

We retrospectively reviewed all patients who underwent ER for upper GIMTs from January 2009 to August 2023. The MTD was measured according to the maximum transverse diameter of specimen immediately retrieved after ER. For the PEBR rate, the independent predictors and optimal cut-off value of MTD were determined by logistic regression analysis and the receiver operating characteristic (ROC) curve analysis. The potential significance of preoperative CT for the evaluation of MTD was also clarified.

RESULTS

A total of 2032 patients were diagnosed with upper GIMTs after en bloc resection under endoscopy. The overall PEBR rate was 98.72% (2006/2032). The PEBR rate was 100% for 1943 GIMTs with MTD < 2.5 cm, 85.71% (60/70) for GIMTs with 2.5 cm but ≤ 3.0 cm, and 15.79% (3/19) for GIMTs with MTD > 3.0 cm, and these rates were significantly different (P < 0.01). In terms of the PEBR rate of GIMTs, the ROC curve revealed that the optimal cut-off MTD value was 3.0 cm, and logistic regression analysis revealed that MTD > 3.0 cm was an independent predictive factor (OR 71.07, 95% CI 9.14-552.43; P < 0.001). The MTD of CT was related to that of the resected specimen (r = 0.7149, P < 0.01), and CT underestimated the mean MTD of upper GIMTs by 0.17 cm (95% CI 0.09-0.24, P < 0.01).

CONCLUSION

MTD is an effective indicator for predicting the PEBR rate of GIMTs after ER. Resected specimens with MTD > 3.0 cm could not be routinely retrieved en bloc. Preoperative CT is suitable for evaluating the MTD of GIMTs, but underestimates the mean MTD of upper GIMTs by 0.17 cm.

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.

Analysis of Thoracoscopic Enucleation Combined with Esophagoscopy in the Prone Position for Esophageal Submucosal Tumor

Background: Esophageal submucosal tumors (SMTs) are rare, occurring in less than 1% of esophageal neoplasms. For surgical treatment of esophageal SMTs, enucleation is usually the procedure of choice for benign tumors. This study aimed at evaluating the surgical technique and outcomes of thoracoscopic enucleation with esophagoscopy for esophageal SMTs. Methods: Patients with esophageal SMTs who underwent thoracoscopic enucleation between 2015 and 2022 were retrospectively investigated. Surgery was performed with the patient in the prone position. First, an esophagoscope was inserted, and a sodium hyaluronate solution with indigo carmine dye was injected into the submucosal layer just below the tumor. Next, under thoracoscopy, the tumor was exposed through a thoracoscopic incision and dissection of the muscularis propria and adventitia was performed at the tumor site. The colored layer resulting from the previously injected dye was identified, and tumor enucleation was performed under guidance of the dye so as not to damage the mucosa or pseudocapsule. Results: In total, 5 surgeries were performed. The mean operative time was 122.6 minutes (range 84-168 minutes), mean blood loss was 21.1 mL (range 0-80 mL), and mean postoperative hospital stay was 8 days (range 7-10 days). There were no postoperative complications. Pathological diagnosis revealed 2 cases of gastrointestinal stromal tumors, 2 cases of schwannoma, and 1 case of leiomyoma. Conclusions: We believe that this technique is a useful and safe method of performing thoracoscopic enucleation of esophageal SMTs because the injected dye provides an indicator of the resection line during enucleation.

A Gastroenterologist's Approach to the Diagnosis and Management of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. These tumors have been shown to harbor oncogenic mutations of the c-kit tyrosine kinase receptor or platelet-derived growth factor receptor alpha (PDGFRA). Immunohistochemical analysis of GISTs allows for the differentiation of these tumors from other mesenchymal tumors of the GI tract such as leiomyomas and leiomyosarcomas. All GISTs have the potential to behave in a malignant fashion. Tumor location, size, and mitotic index are factors used to predict the risk of malignant behavior. Endoscopy and endoscopic ultrasound play a critical role in the diagnosis of GISTs and can yield important information to further risk-stratify tumors and determine management. This article provides a gastroenterologist's perspective on the diagnosis and management of GISTs.

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.

Recent advancement in EUS-guided fine needle sampling

EUS-guided tissue acquisition technique plays an essential role for evaluation of gastrointestinal tumors. Several components affect the yield of EUS-guided tissue acquisition outcomes such as sampling techniques, use of ROSE (rapid onsite evaluation), training and experience, and needle designs. In this review we discuss advancement in EUS-guided fine needle sampling.

Surgical treatment of gastrointestinal stromal tumors of the duodenum: a literature review

Background

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumours in the digestive tract. The duodenal GIST (dGIST) is the rarest subtype, representing only 4-5% of all GIST, but up to 21% of the resected ones. The diagnostic and therapeutic management of dGIST may be difficult due to the rarity of this tumor, its anatomical location, and the clinical behavior that often mimic a variety of conditions; moreover, there is lack of consent for their treatment. This study has evaluated the scientific literature to provide consensus on the diagnosis of dGIST and to outline possible options for surgical treatment.

Methods

An extensive research has been carried out on the electronic databases MEDLINE, Scopus, EMBASE and Cochrane to identify all clinical trials that report an event or case series of dGIST.

Results

Eighty-six studies that met the inclusion criteria were identified with five hundred forty-nine patients with dGIST: twenty-seven patients were treated with pancreatoduodenectomy and ninety-six with only local resection (segmental/wedge resections); in four hundred twenty-six patients it is not possible identify the type of treatment performed (pancreatoduodenectomy or segmental/wedge resections).

Conclusions

dGISTs are a very rare subset of GISTs. They may be asymptomatic or may involve symptoms of upper GI bleeding and abdominal pain at presentation. Because of the misleading clinical presentation the differential diagnosis may be difficult. Tumours smaller than 2 cm have a low biological aggressiveness and can be followed annually by endoscopic ultrasound. The biggest ones should undergo radical surgical resection (R0). In dGIST there is no uniformly adopted surgical strategy because of the low incidence, lack of experience, and the complex anatomy of the duodenum. Therefore, individually tailored surgical approach is recommended. R0 resection with 1-2 cm clear margin is required. Lymph node dissection is not recommended due to the low incidence of lymphatic metastases. Tumor rupture should be avoided.

EUS-FNA WITH 19 OR 22 GAUGES NEEDLES FOR GASTRIC SUBEPITHELIAL LESIONS OF THE MUSCLE LAYER

Background:

Tissue diagnosis is required for gastric subepithelial lesions for differential diagnosis of GISTs. However, there has not been consensus about the best needle for EUS-guided sampling of these lesions.

Aim:

To evaluate the diagnostic yield of EUS-FNA for gastric subepithelial lesions of the proper muscle layer with large-bore 19 gauge needles.

Methods:

A prospectively maintained database was retrospectively reviewed to identify consecutive patients who underwent EUS-FNA with 19 and 22 gauge needles for gastric subepithelial lesions of the fourth endosonographic layer in a tertiary care referral center. EUS-FNA was performed by the same endosonographer, using the fanning technique, without on-site cytopathologist. Specimens were analysed through cell blocks by the same pathologist. Procedure results were categorized into diagnostic, defined as enough material for histopathology and immunohistochemistry, or nondiagnostic.

Results:

Eighty-nine patients (mean age: 59 years, 77% women) underwent 92 EUS-FNA with 19 (75) or 22 (17) gauge needles. Mean lesion size was 22.6 mm. Overall diagnostic yield was 88%. The diagnostic yield of 19 gauge was higher than that of 22 gauge needle (92%x70.6%; p=0.0410), and similar for lesions >2 cm and <2 cm (93.7%x90.7%; p=0.9563). The best performance for 19 gauge needles was obtained performing <3 needle passes. Complication rate was 2.8%.

Conclusions:

Diagnostic yield of EUS-FNA with 19 gauge needles is 92% for gastric subepithelial lesions of the proper muscle layer. It is safe and highly valuable for differentiation between GIST and leiomyoma, no matter the size of the lesion.

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.

How best to manage gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are rare but most common nonepithelial tumor of gastrointestinal tract. They are often found incidentally on computed tomography and endoscopic investigations. Increasing knowledge of the pathogenesis of GISTs and the advent of tyrosine kinase inhibitors revolutionized the management of GISTs. The newer advanced endoscopic techniques have challenged the conventional surgery although the true efficacy and safety of endoscopic approach is not clear at this time. This review article focuses on pathogenesis, diagnosis and management of GISTs.

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.

Endosonographic Features of Gastric Schwannoma: A Single Center Experience

BACKGROUND/AIMS

Gastric schwannomas are rare benign mesenchymal tumors that are difficult to differentiate from other mesenchymal tumors with malignant potential, such as gastrointestinal stromal tumors. This study aimed to evaluate the characteristic findings of gastric schwannomas via endoscopic ultrasonography (EUS).

METHODS

We retrospectively reviewed the EUS findings of 27 gastric schwannoma cases that underwent surgical excision at Pusan National University Hospital during 2007 to 2014.

RESULTS

Gastric schwannomas were mainly located in the middle third of the stomach with a mean tumor size of 32 mm. All lesions exhibited hypoechoic echogenicity, and 24 lesions (88.9%) exhibited heterogeneous echogenicity. Seventeen lesions (63.0%) exhibited decreased echogenicity compared to the normal proper muscle layer. Distinct borders were observed in 24 lesions (88.9%), lobulated margins were observed in six lesions (22.2%), and marginal haloes were observed in 24 lesions (88.9%). Hyperechogenic spots were observed in 21 lesions (77.8%), calcifications were observed in one lesion (3.7%), and cystic changes were observed in two lesions (7.4%).

CONCLUSIONS

During EUS, gastric schwannomas appear as heterogeneously hypoechoic lesions with decreased echogenicity compared to the normal proper muscle layer. These features may be helpful for differentiating gastric schwannomas from other mesenchymal tumors.

Diagnostic accuracy of 22/25-gauge core needle in endoscopic ultrasound-guided sampling: systematic review and meta-analysis

BACKGROUND/AIMS

To compare the diagnostic accuracy of endoscopic ultrasound-guided core needle aspiration with that of standard fine-needle aspiration by systematic review and meta-analysis.

METHODS

Studies using 22/25-gauge core needles, irrespective of comparison with standard fine needles, were comprehensively reviewed. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curves for the diagnosis of malignancy were used to estimate the overall diagnostic efficiency.

RESULTS

The pooled sensitivity, specificity, and DOR of the core needle for the diagnosis of malignancy were 0.88 (95% confidence interval [CI], 0.84 to 0.90), 0.99 (95% CI, 0.96 to 1), and 167.37 (95% CI, 65.77 to 425.91), respectively. The pooled sensitivity, specificity, and DOR of the standard needle were 0.84 (95% CI, 0.79 to 0.88), 1 (95% CI, 0.97 to 1), and 130.14 (95% CI, 34.00 to 495.35), respectively. The area under the curve of core and standard needle in the diagnosis of malignancy was 0.974 and 0.955, respectively. The core and standard needle were comparable in terms of pancreatic malignancy diagnosis. There was no significant difference in procurement of optimal histologic cores between core and standard needles (risk ratio [RR], 0.545; 95% CI, 0.187 to 1.589). The number of needle passes for diagnosis was significantly lower with the core needle (standardized mean difference, -0.72; 95% CI, -1.02 to -0.41). There were no significant differences in overall complications (RR, 1.26; 95% CI, 0.34 to 4.62) and technical failure (RR, 5.07; 95% CI, 0.68 to 37.64).

CONCLUSIONS

Core and standard needles were comparable in terms of diagnostic accuracy, technical performance, and safety profile.

Initial experience with a novel EUS-guided core biopsy needle (SharkCore): results of a large North American multicenter study

BACKGROUND AND AIMS

The ability to safely and effectively obtain sufficient tissue for pathologic evaluation by using endoscopic ultrasound (EUS) guidance remains a challenge. Novel designs in EUS needles may provide for improved ability to obtain such core biopsies. The aim of this study was to evaluate the diagnostic yield of core biopsy specimens obtained using a novel EUS needle specifically designed to obtain core biopsies.

PATIENTS AND METHODS

Multicenter retrospective review of all EUS-guided fine-needle biopsies obtained using a novel biopsy needle (SharkCore FNB needle, Medtronic, Dublin, Ireland). Data regarding patient demographics, lesion type/location, technical parameters, and diagnostic yield was obtained.

RESULTS

A total of 250 lesions were biopsied in 226 patients (Median age 66 years; 113 (50 %) male). Median size of all lesions (mm): 26 (2 - 150). Overall, a cytologic diagnosis was rendered in 81 % specimens with a median number of 3 passes. When rapid onsite cytologic evaluation (ROSE) was used, cytologic diagnostic yield was 126/149 (85 %) with a median number of 3 passes; without ROSE, cytologic diagnostic yield was 31/45 (69 %, P = 0.03) with a median number of 3 passes. Overall, a pathologic diagnosis was rendered in 130/147 (88 %) specimens with a median number of 2 passes. Pathologic diagnostic yield for specific lesion types: pancreas 70/81 (86 %), subepithelial lesion 13/15 (87 %), lymph node 26/28 (93 %). Ten patients (10/226, 4 %) experienced adverse events: 4 acute pancreatitis, 5 pain, 1 fever/cholangitis.

CONCLUSIONS

Initial experience with a novel EUS core biopsy needle demonstrates excellent pathologic diagnostic yield with a minimum number of passes.

A New Method for Endoscopic Sampling of Submucosal Tissue in the Gastrointestinal Tract: A Comparison of the Biopsy Forceps and a New Drill Instrument

Background Sampling of submucosal lesions in the gastrointestinal tract through a flexible endoscope is a well-recognized clinical problem. One technique often used is endoscopic ultrasound-guided fine-needle aspiration, but it does not provide solid tissue biopsies with preserved architecture for histopathological evaluation. To obtain solid tissue biopsies from submucosal lesions, we have constructed a new endoscopic biopsy tool and compared it in a crossover study with the standard double cupped forceps. Methods Ten patients with endoscopically verified submucosal lesions were sampled. The endoscopist selected the position for the biopsies and used the instrument selected by randomization. After a biopsy was harvested, the endoscopist chose the next site for a biopsy and again used the instrument picked by randomization. A total of 6 biopsies, 3 with the forceps and 3 with the drill instrument, were collected in every patient. Results The drill instrument resulted in larger total size biopsies (mm²; Mann-Whitney U test, P = .048) and larger submucosal part (%) of the biopsies (Mann-Whitney U test, P = .003) than the forceps. Two patients were observed because of chest pain and suspicion of bleeding in 24 hours. No therapeutic measures were necessary to be taken. Conclusion The new drill instrument for flexible endoscopy can safely deliver submucosal tissue samples from submucosal lesions in the upper gastrointestinal tract.

Small EUS-suspected gastrointestinal stromal tumors of the stomach: An overview for the current state of management

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors found in the gastrointestinal (GI) tract, with the stomach being the most common site. They represent a distinct group of GI tumors originating from the interstitial cells of Cajal and are characterized by gain-of-function mutations of KIT. KIT oncoprotein serves as both diagnostic and therapeutic targets. Prognosis is related to size, mitotic activity, and site of the tumor. Asymptomatic, small endoscopic ultrasonography (EUS)-suspected GISTs are increasingly encountered with the wide availability of endoscopic/endosonographic examination. The majority of small GISTs are biologically indolent, albeit possibly harboring c-KIT gene mutations. An ongoing controversy exists regarding the management and surveillance policy for small gastric GISTs. A number of reports on the management of GISTs have been published, not confidently addressing the issue of gastric GISTs of small size. This work provides an overview on the current state of management considerations, specifically focusing on small EUS-suspected gastric GISTs, which are increasingly encountered by clinicians.

Clinicopathologic Features of Gastric Schwannoma: 8-Year Experience at a Single Institution in China

To explore the clinicopathologic characteristics, diagnosis, treatment, and prognosis of gastric schwannoma in the imatinib era.The clinicopathologic characteristics and postoperative outcomes of patients diagnosed with gastric schwannoma at our institution between January 2007 and February 2015 were retrospectively collected and analyzed.The main patient complaint was epigastric pain or discomfort. Tumor sizes ranged from 15 to 80 mm (mean, 57.1 mm). In 17 patients, the tumors were located in the body of the stomach. A total of 20 patients were preoperatively misdiagnosed with a gastrointestinal stromal tumor. The rate of correct preoperative diagnosis was only 3.3%. All patients underwent surgical resection and showed strong S-100 protein positivity. Laparoscopic surgery for gastric schwannoma was associated with less blood loss and a shorter postoperative hospital stay than open surgery (P < 0.01). Total 28 patients were disease free without recurrence or metastasis at a median follow-up time of 50 months.Gastric schwannoma is often preoperatively misdiagnosed as gastric gastrointestinal stromal tumor. Laparoscopic resection of gastric schwannoma is considered safe and effective, and it may be the preferred surgery for most small- and moderate-sized tumors. The long-term outcome is excellent, as this type of neoplasm is uniformly benign.

Comparison of EUS-guided tissue acquisition using two different 19-gauge core biopsy needles: a multicenter, prospective, randomized, and blinded study

BACKGROUND AND STUDY AIMS

The optimal core biopsy needle for endoscopic ultrasound (EUS) is unknown. The principle aim of this study is to compare outcomes of EUS-fine-needle biopsy (EUS-FNB) with a new 19-gauge EUS histology needle (ProCore, Cook Medical Inc., Winston-Salem, North Carolina, United States) to a conventional 19-gauge Tru-Cut biopsy (EUS-TCB) needle (19G, Quick-Core, Cook Medical Inc.).

PATIENTS AND METHODS

Patients referred for EUS who require possible histologic biopsy were prospectively randomized to EUS-FNB or EUS-TCB. With the initial needle, ≤ 3 biopsies were obtained until either technical failure or an adequate core was obtained. Patients with suspected inadequate biopsies were crossed over to the other needle and similarly ≤ 3 passes were obtained until adequate cores or technical failure occurred. Technical success, diagnostic histology, accuracy and complication rates were evaluated.

RESULTS

Eighty-five patients (mean 58 years; 43 male) were randomized to FNB (n = 44) and TCB (n = 41) with seven patients excluded. Procedure indication, biopsy site, mass size, number of passes, puncture site, overall technical success and adverse events were similar between the two groups. FNB specimens had a higher prevalence of diagnostic histology (85 % vs. 57 %; P = 0.006), accuracy (88 % vs. 62 %; P = 0.02), mean total length (19.4 vs. 4.3 mm; P = 0.001), mean complete portal triads from liver biopsies (10.4 vs. 1.3; P = 0.0004) and required fewer crossover biopsies compared to those of TCB (2 % vs. 65 %; P = 0.0001). Overall technical success and complication rates were comparable.

CONCLUSION

EUS-FNB using a 19-gauge FNB needle is superior to 19-gauge EUS-TCB needle.

Diagnostic efficacy of endoscopic ultrasound-guided needle sampling for upper gastrointestinal subepithelial lesions: a meta-analysis

BACKGROUND

An increasing number of studies have been conducted on the use of endoscopic ultrasound (EUS)-guided needle sampling for upper gastrointestinal subepithelial lesions (SEL). However, reported diagnostic efficacy varies greatly.

OBJECTIVE

To summarize up current evidences on the diagnostic efficacy of EUS-guided needle sampling for upper GI SEL.

METHOD

A reproducible strategy was used to search four databases. Search results were evaluated for eligibility, and the quality of eligible studies was assessed by QUADAS-2. Pooled efficacy of EUS-guided needle sampling in upper GI SEL was calculated. Procedure-related complications, diagnostic errors, and independent factors related to a higher success rate were also recorded and analyzed.

RESULTS

Seventeen studies, comprising 978 attempts of EUS-guided needle sampling, were included in a meta-analysis. Pooled diagnostic rate of EUS-guided needle sampling was 59.9 %, with a heterogeneity I (2) of 55.2 %. Subgroup analysis showed no difference in diagnostic rate among fine needle aspiration (FNA), trucut needle biopsy (TCB), and fine needle biopsy (FNB), or among 19-, 22-, and 25-G needles. Subgroup analysis and meta-regression suggested that the cell block method might be correlated with a higher diagnostic rate. Few severe complications were reported. Diagnosis errors were rare.

CONCLUSION

EUS-guided needle sampling is a safe, but only moderately effective method for pathology diagnosis of upper GI SEL. Choice of FNA/TCB/FNB, or 19 G/22 G/25 G does not seem to alter the overall diagnostic rate.

Forward-viewing versus oblique-viewing echoendoscopes in the diagnosis of upper GI subepithelial lesions with EUS-guided FNA: a prospective, randomized, crossover study

BACKGROUND

The role of the forward-viewing echoendoscope compared with the oblique-viewing echoendoscope for EUS-guided FNA (EUS-FNA) of upper GI subepithelial lesions has not been defined.

OBJECTIVE

To compare the diagnostic yield and clinical efficacy of EUS-FNA by using the 2 echoendoscopes in the same upper GI subepithelial lesion.

DESIGN

Prospective, randomized, crossover study.

SETTING

Tertiary-care medical center.

PATIENTS

Forty-one patients with an upper GI subepithelial lesion.

INTERVENTIONS

All patients first underwent EUS-FNA with a 19-gauge needle by using both echoendoscopes, based on random selection. When required, 22-gauge or 25-gauge needles were used additionally.

MAIN OUTCOME MEASUREMENTS

Comparison of diagnostic yield, tissue sample area, puncture success rates, procedure time, and adverse events.

RESULTS

Forty-one patients (median lesion size 22 mm, range 15-63 mm) were enrolled. Rates of histologic diagnosis were 80.5% (33/41) and 73.2% (30/41) (P=.453) by using forward-viewing and oblique-viewing echoendoscopes, respectively. Median tissue sample area in GI stromal tumors (n=22) obtained with the forward-viewing echoendoscope was larger than with the oblique-viewing echoendoscope (2.46 mm2 vs 1.00 mm2; P=.046). Puncture success rates were 39 of 41 (95.1%) and 35 of 41 (85.4%; P=.289) with forward-viewing and oblique-viewing echoendoscopes, respectively. Median procedure time was 21 minutes with the forward-viewing echoendoscope and 27 minutes with the oblique-viewing echoendoscope (P=.009). An infectious adverse event occurred in a patient and was treated with antibiotics.

LIMITATIONS

Small sample size.

CONCLUSION

Diagnostic yield did not differ between the 2 echoendoscopes. However, tissue sample area and procedure time were superior with the forward-viewing echoendoscope.

When to puncture, when not to puncture: Submucosal tumors

Subepithelial masses of the gastrointestinal (GI) tract are a frequent source of referral for endosonographic evaluation. Subepithelial tumors most often appear as protuberances in the GI tract with normal overlying mucosa. When there is a need to obtain a sample of the mass for diagnosis, endoscopic ultrasound (EUS) - guided fine-needle aspiration (FNA) is superior to other studies and should be the first choice to investigate any subepithelial lesion. When the decision is made to perform EUS-guided FNA several technical factors must be considered. The type and size of the needle chosen can affect diagnostic accuracy, adequacy of sample size and number of passes needed. The use of a stylet or suction and a fanning or standard technique during EUS-guided FNA are other factors that must be considered. Another method proposed to improve the efficacy of EUS-guided FNA is having an on-site cytopathologist or cytotechnician. Large or well-differentiated tumors may be more difficult to diagnose by standard EUS-FNA and the use of a biopsy needle can be used to acquire a histopathology sample. This can allow preservation of tissue architecture and cellularity of the lesion and may lead to a more definitive diagnosis. Alternatives to FNA such as taking bite-on-bite samples and endoscopic submucosal resection (ESMR) have been studied. Comparison of these two techniques found that ESMR has a significantly higher diagnostic yield. Most complications associated with EUS-FNA such as perforation, infection and pancreatitis are rare and the severity and incidence of these adverse events is not known. Controversy exists as to the optimal method in which to perform EUS-FNA and larger prospective trials are needed.

State of the Art in the Treatment of Gastrointestinal Stromal Tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequently diagnosed mesenchymal neoplasms of the gastrointestinal tract. Despite their biological and clinical heterogeneity, the majority of these tumors are positive for the receptor tyrosine kinase KIT and are driven by KIT- or platelet-derived growth factor receptor alpha (PDGFRA)-activating mutations. There are still uncertainties regarding their clinical and molecular characterization and the optimal treatment regimens, making it difficult to establish a universal treatment algorithm for these tumors.

SUMMARY

From a clinical perspective, the main difference between GISTs and other gastrointestinal neoplasms is that the benign or malignant behavior of GISTs cannot be predicted from histopathology, but instead relies on empirically established scoring systems. Clinical data suggest that malignant potential may be an inherent quality of some GISTs rather than a feature acquired by the tumor during disease progression. Thus, some patients may require prolonged anti-tumor treatment even after complete surgical removal of the tumor.

KEY MESSAGE

Although GISTs are the most frequently occurring mesenchymal neoplasms in the gastrointestinal tract, no universal treatment algorithms exist. This paper reviews the current evidence that guides the management of GISTs.

PRACTICAL IMPLICATIONS

The management of localized GISTs involves the use of surgical resection, with the inclusion of preoperative tyrosine kinase inhibitor treatment for locally advanced, primarily unresectable tumors and for resectable cases requiring extensive surgery. Imatinib is also indicated as adjuvant therapy after complete surgical removal of GISTs with a high estimated risk of recurrence unless specific mutations conferring imatinib resistance are present. The optimal duration of adjuvant treatment is still controversial. For patients with metastatic imatinib-sensitive GISTs, imatinib constitutes the first-line standard treatment. Molecular characterization of the tumor (with respect to the PDGFRA and KIT genes) is mandatory prior to imatinib therapy. Sunitinib and regorafenib are established as alternative treatments for patients demonstrating generalized disease progression on imatinib. New tyrosine kinase inhibitors such as ponatinib and crenolanib as well as drugs targeting alternative pathways are currently under investigation. Surgery and locally ablative treatments may be indicated in some metastatic patients.

Endoscopic ultrasound guided fine needle tissue acquisition: Where we stand in 2013?

Since its introduction, endoscopic ultrasound (EUS) guided fine needle aspiration and fine needle biopsy have become an indispensable tool for the diagnosis of lesions within the gastrointestinal tract and surrounding organs. It has proved to be an effective diagnostic method with high accuracy and low complication rates. Several factors can influence the accuracy and the diagnostic yield of this procedure including experience of the endosonographer, availability of onsite cytopathology services, the method of cytopathology preparation, the location and physical characteristics of the lesion, sampling techniques and the type and size of the needle used. In this review we will outline the recent studies evaluating EUS-guided tissue acquisition and will provide practical recommendations to maximize tissue yield.

Beyond cytology: why and when does the oncologist require core tissue?

There are 2 main reasons why oncologists may require additional tissue and a histologic section in addition to cytopathology from FNA specimens: improved diagnostic accuracy and molecular characterization of tumors. Rather than mutually exclusive diagnostic procedures, EUS-FNA and EUS-CNB must be viewed as supplementary techniques and both approaches should be incorporated as essential tools in the current endoscopic armamentarium.

Techniques for endoscopic ultrasound-guided fine-needle biopsy

Although endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the method of choice to obtain samples to reach definitive diagnosis of lesions of the gastrointestinal tract and of adjacent organs, it cannot fully characterize certain neoplasms. The lack of cytology expertise has hindered the dissemination of EUS, limiting its widespread use. The obtainment of a tissue specimen through EUS fine-needle biopsy (EUS-FNB) may overcome the limitations of EUS-FNA. EUS-FNB is expected to move the practice of EUS from cytology to histology, expanding the use of EUS and facilitating targeted therapies and monitoring of treatment response in a more biologically driven manner.

Tips to overcome technical challenges in EUS-guided tissue acquisition

The diagnostic yield of EUS-FNA depends on several factors, such as the experience of the endosonographer, the characteristics of the lesion, the clinical status of the patient, the size and type of needles, the methods of specimen preparation, as well as cytopathologist expertise. The endosonographic technique can be improved when several tips and tricks useful to overcome challenges of FNA are known. Technical challenges of FNA are related to the characteristics of the lesion and its surroundings, sonographic imaging, and limitations related to the needle. Several tips and tricks necessary to overcome them are presented in this review.

Prediction of risk of malignancy of gastrointestinal stromal tumors by endoscopic ultrasonography

Background/Aims

The accurate preoperative prediction of the risk of malignancy of gastrointestinal stromal tumors (GISTs) is difficult. The aim of this study was to determine whether tumor size and endoscopic ultrasonography (EUS) features can preoperatively predict the risk of malignancy of medium-sized gastric GISTs.

Methods

Surgically resected, 2 to 5 cm gastric GIST patients were enrolled and retrospectively reviewed. EUS features, such as heterogeneity, hyperechoic foci, calcification, cystic change, hypoechoic foci, lobulation, and ulceration, were evaluated. Tumors were grouped in 1 cm intervals. The correlations of tumor size or EUS features with the risk of malignancy were evaluated.

Results

A total of 75 patients were enrolled. The mean tumor size was 3.43±0.92 cm. Regarding the risk of malignancy, 51 tumors (68%) had a very low risk, and 24 tumors (32%) had a moderate risk. When the tumors were divided into three groups in 1 cm intervals, the proportions of tumors with a moderate risk were not different between the groups. The preoperative EUS features also did not differ between the very low risk and the moderate risk groups.

Conclusions

Tumor size and EUS features cannot be used to preoperatively predict the risk of malignancy of medium-sized gastric GISTs. A preoperative diagnostic modality for predicting risk of malignancy is necessary to prevent the overtreatment of GISTs with a low risk of malignancy.

A multidisciplinary approach to the diagnosis and treatment of gastrointestinal stromal tumor

Management of patients with gastrointestinal stromal tumor (GIST) typically involves a combination of surgical, pathologic, and pharmacologic interventions. Gastroenterologists are often the first specialists to encounter patients presenting with GIST and are therefore responsible for facilitating early intervention strategies. Although patients with gastric or small-bowel GISTs typically present with symptoms, a diagnosis of GIST should be considered whenever a submucosal lesion is seen endoscopically. Visualization by standard endoscopy often can determine tumor location and size, although endoscopic ultrasound (EUS) is the most accurate imaging technique for submucosal lesions. Biopsy techniques that yield sufficient tumor samples for diagnostic studies, such as EUS-guided fine needle aspiration, are essential, although other approaches such as EUS-guided core needle biopsy may increase diagnostic yield for subepithelial lesions. Pathology assessment should include immunohistochemical staining for KIT and possibly DOG1 expression, and mutational analysis can have prognostic and predictive value for certain patients. R0 resection is the goal for patients with localized or potentially resectable tumors, which often can be accomplished by laparoscopic resection, even for larger tumors. Medical oncologists play a key role in assessing risk of recurrence after resection and optimizing tyrosine kinase inhibitor therapy in the adjuvant or metastatic setting. Cytoreductive surgery may have value for patients with recurrent or metastatic GIST who exhibit stable disease or respond to tyrosine kinase inhibitor therapy. A coordinated multidisciplinary approach over the course of the disease will serve to enhance communication among GIST team members, reduce risk of progression, and optimize outcomes.

Gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal tract. Soon after GIST was recognized as a tumor driven by a KIT or platelet-derived growth factor receptor mutation, it became the first solid tumor target for tyrosine kinase inhibitor therapies. More recently, alternative molecular mechanisms for GIST pathogenesis have been discovered. These are related to deficiencies in the succinate dehydrogenase complex, NF1-gene alterations in connection with neurofibromatosis type 1 tumor syndrome, and mutational activation of the BRAF oncogene in very rare cases.

Gastrointestinal stromal tumors: diagnosis, therapy and follow-up care in Austria

Optimal treatment for patients suffering from gastrointestinal stromal tumors (GIST) is based on an interdisciplinary treatment approach. Austrian representatives of Medical and Surgical Oncology, Pathology, Radiology, Nuclear Medicine, Gastroenterology, and Laboratory Medicine issued this manuscript on a consensual base within the context of currently available and published literature. This paper contains guidelines and recommendations for diagnosis, therapy, and follow-up of GIST patients in Austria.

Rescue Endoscopic Ultrasound (EUS)-Guided Trucut Biopsy Following Suboptimal EUS-Guided Fine Needle Aspiration for Mediastinal Lesions

Background/Aims

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and Trucut biopsy (TCB) are sensitive techniques for diagnosing mediastinal lesions, but it is unclear how either one or both should be used to obtain a pathologic diagnosis. The objective of our study was to evaluate whether EUS-TCB impacts the diagnosis of mediastinal lesions after the initial on-site review of EUS-FNA specimen suggests a suboptimal result.

Methods

We enrolled consecutive patients with mediastinal lesions who underwent EUS-TCB during the same procedure if the initial EUS-FNA demonstrated an inadequate FNA sample or suggested that histopathology was required for diagnosis. Diagnostic accuracies between procedures were compared as the main outcome.

Results

Twenty-seven patients (14 men; median age, 56 years; range, 19 to 82 years) underwent EUS-FNA and EUS-TCB to evaluate a mediastinal lymphadenopathy or mass (n=17), to determine the cancer stage (n=3) or to exclude tumor recurrence or metastasis (n=7). The overall diagnostic accuracies of EUS-FNA and EUS-TCB were 78% and 67%, respectively (p=0.375). The combined diagnostic accuracy of EUS-FNA plus EUS-TCB was 82%. In six patients with nondiagnostic EUS-FNA, EUS-TCB provided a final diagnosis in one patient (17%).

Conclusions

In the current series of patients with mediastinal masses or adenopathy, the administration of EUS-TCB following suboptimal results for the on-site cytology review did not increase the diagnostic yield.

Use of potassium channel tetramerization domain-containing 12 as a biomarker for diagnosis and prognosis of gastrointestinal stromal tumor

Previously, we showed that the expression of potassium channel tetramerization domain-containing 12 (KCTD12), which was discovered by a proteomics approach, is associated with high-risk behavior of gastrointestinal stromal tumors (GISTs). Here, we examined the distribution and expression of this protein by immunostaining with a commercially available polyclonal KCTD12 antibody in GISTs (n = 64) and other types of malignancy (n = 168) to clarify its diagnostic and clinical significance. Diffuse KCTD12 immunoreactivity was found in most GISTs (52 cases; 81%). KCTD12 expression was observed primarily in vascular endothelial cells, Purkinje cells of the cerebellum, and some neurons scattered throughout the cerebral cortex. KCTD12 was absent from not only the interstitial cells of Cajal but also interstitial cells of Cajal hyperplasia that was encountered incidentally in colon diverticulitis. KCTD12 immunostaining was also seen in malignant peripheral nerve sheath tumors (2/10 cases; 20%), synovial sarcomas (2/10; 20%), solitary fibrous tumor (1/8; 13%), angiosarcoma (1/7; 14%), and colon adenocarcinoma (1/24; 4%). In survival analyses, the 5-year recurrence-free survival rate of patients without KCTD12 expression was only 16.7% compared with 95.6% in those with KCTD12 expression (P < .0001). Ki-67 and KCTD12 were significant predictors of recurrence-free survival, and KCTD12 expression provided additional information about recurrence-free survival after accounting for Ki-67 status. Overall, KCTD12 expression was specific for GISTs from neoplastic and nonneoplastic adult tissues other than brain and served as a predictor of GIST recurrence. These findings suggest that KCTD12 is a useful and reliable biomarker for both the diagnosis and prognosis of GIST.

Gastrointestinal stromal tumors: the role of the gastroenterologist in diagnosis and risk stratification

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that are best classified as sarcomas with variable aggressiveness. They are typically treated with surgical resection and adjuvant tyrosine kinase inhibitors or, for advanced/metastatic GISTs, with tyrosine kinase inhibitors alone. Gastroenterologists are often the first to detect GISTs and are, therefore, tasked with diagnosis and facilitation of early intervention. Diagnostic tools including various imaging techniques such as endoscopic ultrasound (EUS) and EUS-assisted tissue sampling are critical for an accurate diagnosis. In the case of small tumors, EUS-assisted resection or ligation techniques to treat asymptomatic small tumors have been described. This paper reviews current evidence for the diagnosis and management of GISTs, with an emphasis on the role of the gastroenterologist.

Assessment of the technical performance of the flexible 19-gauge EUS-FNA needle

BACKGROUND

A needle made of nitinol has been developed with enhanced flexibility to overcome the limitations of the currently available 19-G EUS-FNA needles.

OBJECTIVE

Evaluate the ability to perform transduodenal FNAs, procure histologic specimens, and undertake therapeutic interventions using the flexible 19-G needle.

DESIGN

Prospective cohort study.

SETTING

Tertiary-care academic medical center.

PATIENTS

Consecutive patients with subepithelial masses, pancreatic head or uncinate lesions, or lesions adjacent to the pancreatic head, and patients undergoing therapeutic intervention.

INTERVENTIONS

Perform tissue acquisition and interventions with the flexible 19-G FNA needle.

MAIN OUTCOME MEASURES

Evaluate the ability to perform transduodenal passes with the flexible 19-G FNA needle. Also, assess the utility of the needle to yield both cytologic and histologic samples and to perform therapeutic interventions.

RESULTS

Of the 50 patients enrolled, tissue acquisition was undertaken in 38 and therapeutic intervention in 12. Of 38 patients from whom tissue was procured, 32 tissue samples were from pancreatic head/uncinate or peripancreatic masses and 6 were from subepithelial masses. Tissue acquisition, which included transduodenal passes, was successful and adequate for cytologic assessment in all 38 patients (100%). Satisfactory histologic specimens were procured from 36 of 38 (94.7%) patients. An onsite diagnosis was established in 35 of 38 (92.1%) patients. In 3 patients with indeterminate/suspicious lesions, a definitive diagnosis was established at histology. A mean of 1.45 ± 0.79 passes per patient was performed. All 12 therapeutic interventions were successful (100%) and included pseudocyst drainage in 5, pelvic abscess drainage in 2, fiducial placement in 2, celiac plexus neurolysis in 2, and cholangiogram in 1. Needle dysfunction or procedural complications were not encountered.

LIMITATIONS

Single-center study with limited power.

CONCLUSIONS

Preliminary data suggest that the flexible 19-G needle can be used for procuring cytologic aspirates and histologic specimens and to undertake therapeutic interventions even by the transduodenal route. Confirmatory studies are required in a larger cohort of patients with varied pathologic conditions to validate these findings.