A prospective study comparing endoscopy and EUS in the evaluation of GI subepithelial masses

Gastric subepithelial masses: evaluation of multidetector CT (multiplanar reconstruction and virtual gastroscopy) versus endoscopic ultrasonography

OBJECTIVES

To assess the role of multidetector computed tomography (MDCT) with multiplanar reconstruction (MPR) and virtual gastroscopy (VG) for detection and differentiation of gastric subepithelial masses (SEMs) by comparison with endoscopic ultrasonography (EUS).

METHODS

Forty-one patients with a suspected SEM were evaluated using EUS and MDCT. MDCT findings were analyzed based on the consensus of two radiologists who were blinded to the EUS findings. The analysis of the CT features included the location, size, and contours of the tumor, the presence of central dimpling, as well as the growth pattern, enhancement pattern, and enhancement degree. The long diameter (LD) and the short diameter (SD) of each lesion were measured and the LD/SD ratios were calculated. EUS and MDCT results were compared with histopathology for the pathologically proven lesions. For the non-pathologically proven lesions, MDCT results were compared with EUS.

RESULTS

Among the 41 patients, 34 SEMs were detected using EUS. For the detection of SEMs with MDCT, a sensitivity of 85.3%, a specificity of 85.7%, a positive predictive value of 96.7%, and a negative predictive value of 54.5% were calculated. The overall accuracy of MDCT for detecting and classifying the SEMs was 85.3 and 78.8%, respectively.

CONCLUSIONS

MDCT with MPR and VG is a valuable method for the evaluation of SEMs. Specific MDCT criteria for various SEMs may be helpful in making an accurate diagnosis.

Contrast-enhanced harmonic endoscopic ultrasound is able to discriminate benign submucosal lesions from gastrointestinal stromal tumors

BACKGROUND

Although endoscopic ultrasound (EUS) has improved the diagnostic of potential malignancies, gastric lesions with suspicion of gastrointestinal stromal tumors (GIST) or benign lesions like lipoma or leiomyoma can often not be accurately differentiated by EUS, therefore, requiring tissue sampling with the risk of bleeding complications especially in GIST. As with the newest generation of EUS machines, contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) has become a new option to determine perfusion characteristics. The aim of this analysis was to evaluate whether CEH-EUS may help to discriminate various submucosal lesions.

METHODS

Data sets of 17 patients with suspicious gastric or esophageal lesions, who were investigated with CEH-EUS were analyzed. Perfusion characteristics were classified by the investigator immediately and statistically analyzed after investigation. Samples from EUS-fine needle aspirates, biopsy samples after needle cut or surgical specimen served as gold standard.

RESULTS

CEH-EUS showed nine lesions with reduced contrast enhancement (maximum intensity 6.2 ± 1.9 db) and eight lesions with hyperenhancement (47.3 ± 11.6 db). The latter eight lesions were all histologically identified as GIST, while the nine hypoenhanced lesions emerged to be four lipoma and five leiomyoma. Statistical analysis corresponded with initial perfusion classification in all cases.

CONCLUSION

This is the first study showing that CEH-EUS can discriminate GIST from benign lesions with good accuracy. In the future, CEH-EUS-guided discrimination may lead to individualized diagnostic and therapeutic strategies in handling submucosal lesions.

Ecoendoscopia nas lesões subepiteliais do trato digestório: artigo de revisão

Lesões subepiteliais ou abaulamentos da mucosa são recobertas por mucosa normal e geralmente assintomáticas. Sua maioria é diagnosticada em exames radiológicos ou de endoscopia digestiva e podem corresponder a qualquer camada da parede do órgão (intramural) ou serem extramurais. Este artigo descreve estudos para análise da ultrassonografia após ecoendoscopia (USE) como método diagnóstico de elevada acurácia diante do achado de lesão subepitelial. Trata-se de trabalho de revisão de literatura sobre as características ecoendoscópicas das lesões subepiteliais e diferenciação em intra ou extramurais, camada de origem, ecogenicidade, vascularização, margens e dimensões, punção aspirativa por agulha fina (PAAF) ou biópsias com agulha do tipo trucut. Ambas as formas são aceitáveis) para análise histológica. A ultrassonografia endoscópica tem melhores índices de acurácia no diagnóstico da camada da parede gastrointestinal comprometida por lesões ou massas, além de estudar a ecogenicidade da lesão. A ultrassonografia endoscópica é um método seguro e detalhado, considerado o melhor exame de imagem para diagnóstico definitivo e programação terapêutica das lesões subepiteliais.

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.

Endoscopic ultrasonography-guided diagnosis of subepithelial tumors

Subepithelial lesions are frequently discovered during routine endoscopic examinations. These lesions represent a wide spectrum of heterogeneous benign to malignant conditions. Most of these lesions are asymptomatic. There is no consensus regarding how to manage these lesions. Over the last 2 decades, the approach to these lesions has significantly improved owing to the introduction of endoscopic ultrasonography, fine-needle aspiration, immunohistochemical staining methods, and different treatment options. This article discusses the nature of subepithelial lesions, focusing on the most recent developments that use endoscopic ultrasonography to diagnose and manage these lesions.

Small intestine gastrointestinal stromal tumors

PURPOSE OF REVIEW

To review the contemporary management of gastrointestinal stromal tumor (GIST), including endoscopy, surgery, and systemic therapy, highlighting the aspects unique to small intestinal tumors.

RECENT FINDINGS

Tumor size, mitotic count, and site of origin are the three key prognostic factors, with mitotic count being the single strongest predictor of recurrence. Tumors arising in the small bowel have worse prognosis than those of comparable size and mitotic count arising in other organs. Endoscopy and endoscopic ultrasound-guided, fine-needle aspiration are key components in the diagnosis of GIST. The role of endoscopy in surveillance and resection remain investigational. Surgery, either open or laparoscopic, remains the only curative option, but recurrence rates are high. Adjuvant therapy with imatinib mesylate improves recurrence-free survival rates and may improve overall survival (OS) with longer duration of treatment. Neoadjuvant imatinib may play an important role in the management of patients with locally advanced disease. For patients with advanced disease, first-line imatinib and second-line sunitinib malate have improved progression-free and OS rates. Systemic treatment should be continued life-long or until treatment failure.

SUMMARY

Advances in the last decade have dramatically changed the management and prognosis of patients with primary and advanced GIST.

Endoscopic management of gastrointestinal stromal tumors

Subepithelial lesions are increasingly being identified with improved endoscopic imaging technologies. Many of these lesions are now recognized as gastrointestinal stromal tumors (GISTs). Recent advances in immunohistochemistry have allowed for reliable differentiation of GISTs from other subepithelial tumors, thereby significantly improving our understanding of these lesions. The wealth of recent information and continual evolution in our understanding of GISTs has exposed some knowledge gaps pertaining to the optimal management of these lesions. In this article, we review the endoscopic management of GISTs as it relates to the identification, diagnosis and management of these lesions based on the best available literature and our own clinical experience to date.

Pediatric gastrointestinal stromal tumor

Pediatric gastrointestinal stromal tumor (GIST) is a rare entity that can be quite different from its adult counterpart. This report provides a comprehensive review on the diagnosis and management of this tumor in children and adolescents, including its oncogenesis and associated syndromes. Surgery remains a mainstay of treatment, but there are no standard guidelines available at this time regarding the best practice for multimodality therapy as our understanding of the biology of GIST is still in evolution. Therefore, pediatric patients with GIST should be ideally treated in the context of clinical trials at specialized, multidisciplinary centers throughout the course of their disease, especially because these patients may live for years after diagnosis.

Are endoscopic ultrasonography imaging characteristics reliable for the diagnosis of small upper gastrointestinal subepithelial lesions?

PURPOSE OF THE STUDY

To compare the accuracy of endoscopic ultrasonography (EUS) imaging with histopathology in the diagnosis of upper gastrointestinal subepithelial lesions.

METHODS

Thirty-seven patients (21 female; mean age: 55 y) underwent endoscopic submucosal resection (ESMR) of upper gastro intestinal subepithelial lesions at a tertiary care facility. All patients underwent EUS before ESMR of the lesion. Information regarding location, size, echogenecity, layer of origin, presumptive diagnosis based on EUS imaging, and histopathology diagnosis after ESMR of the subepithelial lesion was recorded.

RESULTS

Twenty-seven subepithelial lesions were resected from the stomach, 5 from the esophagus, and 5 from the duodenum. The mean size of the lesions was 9 mm (range, 6-18 mm). Thirty-six lesions originated from the submucosa, and 1 from the muscularis propria. Using histopathology as the gold standard, the overall diagnostic accuracy of EUS imaging was 49% (18 out of 37). The accuracy of EUS imaging for the diagnosis of esophageal, gastric, and duodenal subepithelial lesions was 20%, 56%, and 40%, respectively. One patient developed a microperforation, and 1 developed bleeding during the ESMR procedure. No complications were reported with the EUS procedure.

CONCLUSIONS

The diagnostic accuracy of EUS imaging is inferior to histopathology in the diagnosis of small upper gastrointestinal subepithelial lesions. Endoluminal resection is a relatively safe and noninvasive modality that not only provides tissue sample for accurate diagnostic interpretation, but also aids in the complete removal of small subepithelial lesions of the upper gastrointestinal tract.

Imaging modalities of gastrointestinal stromal tumors

Recent dramatic improvement of survival of Gastrointestinal stromal tumor patients alongside the development of a new targeted treatment has made the role of imaging increasingly more important not only in diagnosing the disease, but also in monitoring the treatment effect and surveillance. Computed tomography is currently the imaging modality of choice for these purposes. This article reviews the current roles of different imaging modalities in clinical management of the gastrointestinal stromal tumors.

Upper endoscopy versus endosonography in differential diagnosis of gastrointestinal bulging

CONTEXT

The identification of a bulging covered by normal epithelium is a common finding during an upper gastrointestinal endoscopy.

OBJECTIVE

To compare the endoscopic and endosonography findings in the differential diagnosis of the gastrointestinal bulging (subepithelial tumor or extrinsic compression).

METHOD

Patients referred by endosonography with bulging of upper gastrointestinal tract were studied retrospectively. The size, location, consistency and presumptive diagnosis were recorded at time of endoscopy and endosonography. Endosonography-guided fine-needle aspiration was proposed in case of uncertain diagnose to increase diagnostic sensitivity.

RESULTS

One hundred seventy-six patients (93 women) and mean age 62.5 years (10-87). One hundred fifty-three had subepithelial tumor and 23 had extrinsic compression as a final diagnosis. Endosonography had sensitivity, specificity and accuracy higher than those found by endoscopy for both diagnosis subepithelial tumor and extrinsic compression. Endoscopy and endosonography showed poor concordance (K = 0.13) for subepithelial tumor diagnosis and unsuitable agreement for diagnosis in extrinsic compression (K = 0.01). The endosonography-guided fine-needle aspiration had sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 75%, 72.4%, 80.5%, 65.6% and 74%, respectively.

CONCLUSION

Endoscopy has high sensitivity and low specificity for subepithelial tumor and both are low for the extrinsic compression. Endoscopy is a good tool for diagnosis of the subepithelial tumors, but not to determine the cause of an extrinsic compression. The endosonography identifies the layer from which subepithelial tumor comes, obtain histological samples, and increasing the diagnostic accuracy.

Clinical impact of EUS-guided Trucut biopsy results on decision making for patients with gastric subepithelial tumors ≥ 2 cm in diameter

BACKGROUND

Preoperative pathologic diagnosis of a gastric subepithelial tumor (SET) may improve clinical decision making. However, the clinical impact of EUS-guided Trucut biopsy (EUS-TCB) data on decision making in patients with a gastric SET has not been assessed.

OBJECTIVE

To evaluate the impact of EUS-TCB information on the clinical management of patients with a gastric SET.

DESIGN

Retrospective review of prospectively collected data.

SETTING

Tertiary referral center.

PATIENTS

Sixty-five patients with gastric SETs 2 cm or larger in diameter.

INTERVENTION

EUS-TCB.

MAIN OUTCOME MEASUREMENTS

The number of patients for whom treatment plans were changed because of EUS-TCB results.

RESULTS

Nine SETs were not punctured by the TCB needle because of technical problems, and we were unable to obtain adequate subepithelial tissue from 19 SETs. Treatment plans were changed for 18 of 65 patients (27.7%). The changes were avoiding unnecessary resection (7 benign SETs ≥ 3 cm in diameter), scheduling for definitive treatment (6 GI stromal tumors and 1 carcinoid tumor), and modifying the surgical field (3 large GI stromal tumors and 1 carcinoma). When we assessed treatment plans relative to tumor location, we found that avoiding unnecessary resection was associated with the presence of cardiac SETs.

LIMITATIONS

Retrospective study with a small number of patients.

CONCLUSIONS

EUS-TCB changed or influenced management decisions in 18 of 65 patients (27.7%) with gastric SETs. Patients could receive proper and tailored surgery, medical treatment, or surveillance according to size and location of SETs with EUS-TCB.

Estimation of malignant potential of GI stromal tumors by contrast-enhanced harmonic EUS (with videos)

BACKGROUND

Contrast-enhanced harmonic EUS (CEH-EUS) is a new sonographic technique that uses US contrast agents and depicts intratumoral vessels in real time.

OBJECTIVE

To evaluate whether assessment of tumor vascularity by CEH-EUS can predict the preoperative malignancy risk of GI stromal tumors (GISTs).

DESIGN

Prospective study to observe GIST vascularity.

SETTING

Kinki University School of Medicine.

PATIENTS

Between June 2007 and September 2009, 76 consecutive patients suspected of having subepithelial lesions underwent CEH-EUS.

INTERVENTION

CEH-EUS was performed by using a prototype echoendoscope in an extended pure harmonic detection mode.

MAIN OUTCOME MEASUREMENTS

Resected GIST specimens in 29 patients who underwent surgical resection were divided into high-grade (n=16) and low-grade (n=13) malignancy groups based on mitotic activity. The abilities of EUS-guided FNA and CEH-EUS to diagnose the malignant potential were compared. The sensitivities with which contrast-enhanced multidetector CT, power-Doppler EUS, and CEH-EUS detected intratumoral vessels in high-grade malignancy GISTs also were compared.

RESULTS

CEH-EUS identified irregular vessels and thereby predicted GIST malignancies with a sensitivity, specificity, and accuracy of 100%, 63%, and 83%, respectively. Diagnosis of high-grade malignancy GISTs by EUS-guided FNA had a sensitivity, specificity, and accuracy of 63%, 92%, and 81%, respectively. Contrast-enhanced multidetector CT, power-Doppler EUS, and CEH-EUS detected intratumoral vessels in high-grade malignancy GISTs with sensitivities of 31%, 63%, and 100%, respectively (P<.05).

LIMITATIONS

A single center was involved in this study.

CONCLUSIONS

CEH-EUS successfully visualized intratumoral vessels and may play an important role in predicting the malignancy risk of GISTs.

Duodenal duplication cyst and pancreas divisum causing acute pancreatitis in an adult male

Duodenal duplication cysts are rare congenital abnormalities which are more commonly diagnosed in infancy and childhood. However, in rare cases, these lesions can remain asymptomatic until adulthood. The combination of duplication cyst and pancreas divisum is extremely rare and both conditions have been linked with acute recurrent pancreatitis. We present the case of a 37 years-old patient who presented with repeated episodes of acute pancreatitis. By means of magnetic resonance imaging and endoscopic ultrasonography we discovered a duplication cyst whose cavity received drainage from the dorsal pancreas. After opening the cyst cavity to the duodenal lumen with a needle knife the patient presented no further episodes in the clinical follow-up. Comparable literature findings and therapeutic options for these abnormalities are discussed with regard to the presented case.

Digital image analysis is a useful adjunct to endoscopic ultrasonographic diagnosis of subepithelial lesions of the gastrointestinal tract

OBJECTIVE

The purpose of this study was to explore the role of digital image analysis in differentiating endoscopic ultrasonographic (EUS) features of potentially malignant gastrointestinal subepithelial lesions (SELs) from those of benign lesions.

METHODS

Forty-six patients with histopathologically confirmed gastrointestinal stromal tumors (GISTs), carcinoids, and lipomas who had undergone EUS evaluation were identified from our database. Representative regions of interest (ROIs) were selected from the EUS images, and features were extracted by texture analysis. On the basis of these features, an artificial neural network (ANN) was built, trained, and internally validated by unsupervised learning followed by supervised learning. Outcomes were the performance characteristics of the ANN.

RESULTS

A total of 106, 111, and 124 ROIs were selected from EUS images of 8, 10, and 28 patients with lipomas, carcinoids, and GISTs, respectively. For each ROI, 228 statistical parameters were extracted and later reduced to the 11 most informative features by principal component analysis. After training with 50% of the data, the remainder of the data were used to validate the ANN. The model was "good" in differentiating carcinoids and GISTs, with area under the receiver operating characteristic curve (AUC) values of 0.86 and 0.89, respectively. The model was "excellent" in identifying lipomas correctly, with an AUC of 0.92.

CONCLUSIONS

Digital image analysis of EUS images is a useful noninvasive adjunct to EUS evaluation of SELs.

Diagnosis of subepithelial tumors in the upper gastrointestinal tract by endoscopic ultrasonography

Endoscopic ultrasonography (EUS) is the most accurate procedure for detecting and diagnosing subepithelial tumors, due to its higher sensitivity and specificity than other imaging modalities. EUS can characterize lesions by providing information on echogenic origin, size, borders, homogeneity, and the presence of echogenic or anechoic foci. Linear echoendoscopes, and recently also electronic radial echoendoscopes, can be used with color Doppler or power Doppler to assess the vascular signals from subepithelial masses, and thus permit the differentiation of vascular structures from cysts, as well as the assessment of the tumor blood supply. However, the diagnostic accuracy of EUS imaging alone has been shown to be low in subepithelial lesions with 3rd and 4th layers. It is also difficult to differentiate exactly between benign and malignant tumors and to gain an accurate picture of histology using EUS. On the other hands, EUS guided fine needle aspiration (EUS-FNA) can provide samples for cytologic or histologic analysis. Hypoechoic lesions of the 3rd and the 4th EUS layers, more than in 1 cm diameter are recommended, and histologic confirmation using endoscopic submucosal resection or EUS-FNA should be obtained when possible. Therefore, EUS-FNA plays an important role in the clinical management of subepithelial tumors. Furthermore improvements in endoscopic technology are expected to be more useful modalities in differential diagnosis and discrimination between benign and malignant subepithelial tumors.

Endoscopic enucleation for gastric subepithelial tumors originating in the muscularis propria layer

BACKGROUND

Subepithelial tumors (SETs) of the stomach are considered benign. However, they have the potential for malignant transformation, especially if they originate in the muscularis propria layer. This study aimed to determine the feasibility of endoscopic enucleation (EEN) for SETs in the muscularis propria layer and to evaluate the diagnostic efficacy and safety of EEN for SETs.

METHODS

A total of 65 lesions in 64 patients were eligible for inclusion in the study during the period between June 2006 and September 2009. En bloc enucleation using an insulated-tip knife and snare was attempted for removal of gastric SETs from the muscularis propria.

RESULTS

A total of 60 tumors were successfully resected by EEN (success rate, 92.3%). The mean tumor size, determined by endoscopic ultrasound, was 13.8 mm (range, 5-30 mm). A histologic diagnosis was obtained for 63 tumors (diagnostic yield, 96.9%), which was leiomyoma for 32 lesions, gastrointestinal stromal tumor for 26 tumors, and other for 5 tumors. The rate for complete resection in relation to the location of the lesion in the stomach was higher for the cardia, the mid/lower body (100%), and the high body (96%) than for the fundus (75%) or the antrum (50%, p=0.006). The rate of perforation was significantly higher for the fundus (50%) than for other locations (0% for the cardia and 4% for the high body) (p<0.001).

CONCLUSIONS

Endoscopic enucleation of gastric SETs originating in the muscularis propria layer was a safe and effective method for the histologic diagnosis and removal of small gastric SETs, especially those located in the cardia and the high body of the stomach.

Accuracy of EUS in the evaluation of small gastric subepithelial lesions

BACKGROUND

EUS combined with endoluminal resection techniques is increasingly used to provide a definitive diagnosis of small gastric subepithelial lesions seen on standard upper endoscopy.

OBJECTIVE

To evaluate the accuracy of EUS in diagnosing small gastric subepithelial lesions by using histology as the criterion standard.

DESIGN

A retrospective study.

SETTING

Academic tertiary care center.

PATIENTS

A total of 22 patients (15 women, mean age 62.2 years) with an endoscopically resected gastric subepithelial lesion were included in this 3-year retrospective study.

MAIN OUTCOME MEASUREMENTS

The size, echogenicity, the layer of origin, and presumptive diagnosis were determined by EUS. The diagnostic accuracy of EUS was determined by using histology as the criterion standard.

RESULTS

The mean size of the 22 lesions was 13.6 mm (range 8-20 mm). An endoscopic cap band mucosectomy device was used to resect 16 (72.7%) lesions, whereas 6 (27.3%) were resected with a saline solution-assisted and snare technique. Using histology as a criterion standard, we found that the accuracy of the EUS diagnosis was 10 of 22 (45.5%). EUS alone had an accuracy rate of 30.8% and 66.7%, respectively, in the diagnosis of neoplastic and non-neoplastic lesions.

LIMITATIONS

A single-center, retrospective analysis.

CONCLUSION

EUS imaging had a low accuracy rate in the diagnosis of gastric subepithelial lesions, and endoscopic submucosal resection should be performed to provide a histologic diagnosis. Resection of small subepithelial lesions of 20 mm or less can be accomplished en bloc with an endoscopic cap band mucosectomy device.

Clinical course of subepithelial lesions detected on upper gastrointestinal endoscopy

AIM: To evaluate the natural history of subepithelial lesions.

METHODS: We reviewed the medical records of 104 159 patients who underwent upper gastrointestinal endoscopy at the Center for Health Promotion of Samsung Medical Center between 1996 and 2003. Subepithelial lesions were detected in 795 patients (0.76%); 252 patients were followed using upper gastrointestinal endoscopy for 82.5 ± 29.2 mo (range, 12-160 mo; median, 84 mo; 1st quartile, 60 mo; 3rd quartile, 105 mo). The median interval of follow-up endoscopy was 12 mo (range, 6-105 mo; 1st quartile, 12 mo; 3rd quartile, 24 mo).

RESULTS: The mean patient age was 53 years (range, 22-80 years), and the male-to-female ratio was 2.36:1 (177/75). The lesion size at initial measurement averaged 8.9 mm (range, 2-25 mm; median, 8 mm; 1st quartile, 5 mm; 3rd quartile, 10 mm). Of the 252 lesions, 244 (96.8%) were unchanged and 8 (3.2%) were significantly increased in size (from 12.9 ± 6.0 to 21.2 ± 12.2 mm) after a mean interval of 59.1 ± 27.5 mo (range, 12-86 mo). Surgical resection of lesions was performed when the lesions were ≥ 3 cm in diameter. Two lesions were diagnosed as gastrointestinal stromal tumors with an intermediate or high risk of malignancy and one lesion was classified as a schwannoma.

CONCLUSION: Most small subepithelial lesions do not change as shown by endoscopic examination, and regular follow-up with endoscopy may be considered in small, subepithelial lesions, especially lesions < 1 cm in size.

The role of endosonography in submucosal tumours

Submucosal tumours (SMTs) are relatively common findings in patients undergoing endoscopy, especially in upper gastrointestinal (GI) tract. This term includes various non-neoplastic and neoplastic conditions. Endoscopic ultrasonography (EUS) is the best imaging procedure to characterise SMT and to determine the need for further explorations. In this review, the following issues will be addressed: the endosonographic features of SMT; the diagnostic accuracy of EUS; the ability of EUS to distinguish benign and malignant SMTs; the value of EUS-guided fine-needle aspiration (FNA); and the influence of EUS on clinical management.

The natural history of upper gastrointestinal subepithelial tumors: a multicenter endoscopic ultrasound survey

GOALS

To evaluate the natural course of <3-cm upper gastrointestinal subepithelial tumors by endoscopic ultrasound (EUS) and to determine the appropriate timing for EUS follow-up.

BACKGROUND

Subepithelial tumors (SETs) can range from benign lesions to tumors with malignant behavior or potential to become malignant such as gastrointestinal stromal tumors (GISTs). EUS is considered a valuable tool for their evaluation as it estimates the exact size and layer of origin, and also additional morphologic features that can suggest the diagnosis. For high surgical risk patients and when no worrisome EUS features are seen, EUS surveillance of subepithelial tumors is often used.

METHODS

Fifty-one patients (mean age, 61.2+/-11.8 y; median, 63 y) with asymptomatic <3-cm SETs of second and fourth echolayer were followed for a mean period of 29.7 months (range, 3 to 84; median, 23 mo) in 3 tertiary care institutions. Evaluation included location, echolayer, tumor diameter, internal echo pattern, and outer margin of lesions by EUS. EUS was performed by using miniprobes, radial and linear echoendoscopes.

RESULTS

Follow-up revealed increase in size and/or change in echogenic features in 7/51 (13.7%) patients. Surgical follow-up was available for 3 of 7 of these patients. Two of the fourth layer SETs, which had both increase in size and change in echogenicity were found to be GISTs (+c-kit).

CONCLUSIONS

The majority of <3-cm SETs does not change during a median of 23 months. The change in echogenicity and increase in size may indicate a GIST.

EUS-guided sampling of suspected GI stromal tumors

BACKGROUND

The diagnostic yield of EUS-guided FNA (EUS-FNA) of suspected GI stromal tumors (GIST) has not been assessed in large series.

OBJECTIVE

Our purpose was to determine the diagnostic yield of EUS-FNA of subepithelial lesions with EUS features suggestive of GIST.

DESIGN

Retrospective database review.

SETTING

Tertiary care referral center and an urban Veterans Administration hospital.

PATIENTS

Consecutive patients referred for EUS evaluation of upper GI subepithelial lesions of the fourth endosonographic layer who underwent EUS-FNA.

MAIN OUTCOME MEASUREMENTS

Proportion of patients whose cytopathologic examination was diagnostic (immunohistochemical stains establish a specific diagnosis), suspicious (spindle cells identified, quantity not sufficient for specific stains), or nondiagnostic.

RESULTS

A total of 112 patients (45.5% female, mean age 61.6 years) underwent EUS-FNA (mean number of FNA passes 5.3). Tumor location was as follows: stomach 62.5%, esophagus 30.4%, and duodenum 7.1%. EUS-FNA was diagnostic in 61.6%, suspicious (spindle cells) in 22.3%, and nondiagnostic in 16.1%. The histologic results were 31.3% GIST, 26.8% leiomyomas, 22.3% spindle cell neoplasms, 3.5 % neural tumors, and 16.1% nondiagnostic. Fifteen (12.5%) patients also underwent EUS-guided core needle biopsy needle sampling; 7 were diagnostic, 2 suspicious, and 6 nondiagnostic. Twenty-four (20.0%) patients underwent jumbo forceps sampling; 5 were diagnostic, 1 suspicious, and 18 nondiagnostic. There were no cases of diagnostic core needle biopsy after nondiagnostic FNA core needle biopsy. Jumbo forceps biopsy of ulcerated masses was diagnostic in 3 GISTs in which FNA was nondiagnostic. Univariate and multivariate analyses showed that no variable was associated with an increased diagnostic yield.

CONCLUSIONS

EUS-FNA sampling of subepithelial lesions was diagnostic in 61.6% and showed a spindle cell neoplasm ("suspicious") in another 22.3% (diagnostic yield 83.9%). Core needle biopsy needle sampling did not increase the yield, but in the setting of an ulcerated mass, forceps biopsy may be diagnostic.

A guide for the diagnosis and management of gastrointestinal stromal cell tumors

Gastrointestinal stromal cell tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract and are frequently detected on routine endoscopy. Although only approximately 10-30% of GISTs are clinically malignant, all may have some degree of malignant potential. Preoperative determination of malignancy risk can be estimated from tumor size and location, but reliable histopathologic criteria are not currently available. Given such biological uncertainty, accurate diagnosis is essential to differentiate these lesions from other truly benign, subepithelial tumors. Endoscopic ultrasound-guided fine-needle aspiration has emerged as an important procedure to secure a tissue diagnosis of a GIST. When encountering GISTs, gastroenterologists are faced with challenging management decisions, especially in the face of small, incidentally discovered lesions. The majority of localized GISTs are managed via surgical resection, although a select few may be observed using serial endoscopic ultrasound examinations. This Review provides a general overview of GISTs, with an emphasis on their endoscopic diagnosis, the management of localized disease, and the management of incidentally discovered GISTs.

Subepithelial mass lesions in the upper gastrointestinal tract

The finding of a mass lesion in the upper gastrointestinal tract at endoscopy with apparent normal overlying mucosa is common. The differential diagnosis of such lesions is broad and includes those of intramural or extramural origin. Endoscopic ultrasound provides accurate imaging of subepithelial mass lesions and characterizes them according to size, echogenicity, and origin including the histologic layer if the lesion is intramural which narrows the differential diagnosis. Endoscopic ultrasound allows a guided tissue sample to be obtained for histologic confirmation which is especially important for hypoechoic lesions arising from the 3rd or 4th echogenic layers. The purpose of this article is to review the diagnosis of the more common subepithelial mass lesions with an emphasis on endoscopic ultrasound and the subsequent management or monitoring.

Endoscopic diagnosis of gastrointestinal stromal cell tumors

PURPOSE OF REVIEW

To outline the recommended course of action when a subepithelial lesion is encountered during upper endoscopy. It will focus on the endoscopic and endosonographic features common to gastrointestinal stromal tumors, and the optimal tests performed to confirm the diagnosis of a gastrointestinal stromal tumor.

RECENT FINDINGS

The major recent finding of a mutation in the protooncogene c-kit which is unique to gastrointestinal stromal tumors has led to their reclassification as separate from other spindle cell tumors. Endoscopic ultrasound is a key component of the evaluation of submucosal lesions of the gastrointestinal tract, allowing determination of the wall layer of origin of the lesion and diagnostic sampling. Endosonographic features of gastrointestinal stromal tumors associated with high-risk lesions include size larger than 4-5 cm, irregular or invasive border, cystic spaces and malignant appearing lymph nodes. Endoscopic ultrasound-guided fine needle aspiration is generally adequate for tissue acquisition. Immunohistochemical analysis is performed on the tissue to differentiate gastrointestinal stromal tumors from other spindle cell neoplasms.

SUMMARY

The clinical behavior of gastrointestinal stromal tumors is variable. Accurate preoperative endoscopic characterization of the lesion with fine needle aspiration is critical for treatment decisions and for an assessment of prognosis.

American Gastroenterological Association Institute technical review on the management of gastric subepithelial masses

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on January 19, 2006, and by the AGA Institute Governing Board on April 20, 2006.