Staging with computed tomography of patients with colon cancer.

PURPOSE: Accurate staging of colonic cancer is important for patient stratification. We aimed to correlate the diagnostic accuracy of preoperative computed tomography (CT) with final histopathology as reference standard. METHODS: Data was collected retrospectively on 615 consecutive patients operated for colonic cancer. Evaluation was based upon T-stage. Patients were stratified into high-risk and low-risk groups, based on the extent of tumor invasion beyond the proper muscle layer of more or less than 5 mm. The Kendall tau correlation coefficient was used to calculate concordance between radiological (r)T-stage obtained at CT imaging and pathological (p)T-stage from the final pathology. RESULTS: In total, 501 patients were included. We found no significant differences in the Kendall tau values for diagnostic measures between the groups at the 95% confidence interval (CI) level: 49% (95% CI, 43-55) for all individuals, 48% (95% CI, 40-56) for screened individuals, and 47% (95% CI, 37-56) for non-screened individuals. The overall sensitivity and specificity for all individuals in identifying high-risk tumors on CT was 65% (95% CI, 56-73) and 89% (95% CI, 85-92). The risk of ending up in the high-risk group due to overstaging among all individuals was calculated as the number needed to harm 11.7 (95% CI, 9-16). CONCLUSIONS: There is basis for improvement of CT-based preoperative staging of patients with colorectal cancer. Supplementary modalities may be needed for correct staging of patients preoperatively, especially in relation to stratification of patients into neoadjuvant treatments or tailored therapy in patients with early cancers.

Endoscopic ultrasonography and computed tomography scanning for preoperative staging of colonic cancer.

PURPOSE: With an increasing demand for more accurate preoperative staging methods for colon cancer, we aimed to compare preoperative tumour (T)- and nodal (N)-stage in patients with left-sided colon cancer by endoscopic ultrasonography (EUS) and computed tomography (CT) with post-operative histology as gold standard. METHODS: A total of 44 patients were prospectively recruited at Herlev and Roskilde University Hospitals during November 2014-January 2016. Thirty-five patients were included in the final analysis and underwent EUS, CT and surgery within 2 weeks. Diagnostic values were evaluated for "low risk" (T1+T2+T3 with ≤5 mm extramural invasion) and "high risk" (T3 with >5 mm of extramural spread + T4) colonic cancer. RESULTS: Sensitivity and specificity in "low risk" colonic cancer evaluated with EUS was 0.90 [0.74;0.98] and 0.75 [0.19;0.99] and with CT 0.96 [0.80;0.99] and 0.25 [<0.01;0.81]. EUS and CT were poor in predicting N0 or N+ disease. CONCLUSIONS: The sensitivity of EUS and CT were good and comparable regarding T-stage evaluation, while EUS had a significantly higher specificity in the evaluation of "low risk" tumours. The results obtained for "high risk" colonic cancer were difficult to evaluate due to small patient numbers. EUS could be considered as a supplement to CT scans in selecting patients for neoadjuvant therapies, or local transmural treatment, in the future. TRIAL REGISTRATION: NCT02324023.

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided interventions: General Aspects and EUS-guided Sampling (Short Version).

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle-based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (short version; the long version is published online).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part IV - EUS-guided Interventions: General aspects and EUS-guided sampling (Long Version).

The fourth part of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines on Interventional Ultrasound describes general aspects of endoscopic ultrasound-guided diagnostic and therapeutic interventions and assesses the evidence for endoscopic ultrasound-guided sampling. Endoscopic ultrasound combines the most advanced high-resolution ultrasound imaging of lesions within the wall and in the vicinity of the gastrointestinal tract and safe and effective fine needle based tissue acquisition from these lesions. The guideline addresses the indications, contraindications, techniques, adverse events, training and clinical impact of EUS-guided sampling. Advantages and drawbacks are weighed in comparison with image-guided percutaneous biopsy. Based on the most current evidence, clinical practice recommendations are given for crucial preconditions and steps of EUS-guided sampling as well as for safe performance. Additionally, the guideline deals with the principles and reliability of cytopathological reporting in endoscopic ultrasound-guided sampling (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V.

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation in clinical practice (long version).

EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part V - EUS-Guided Therapeutic Interventions (short version).

The fifth section of the Guidelines on Interventional Ultrasound (INVUS) of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) assesses the evidence for all the categories of endoscopic ultrasound-guided treatment reported to date. Celiac plexus neurolysis and block, vascular intervention, drainage of fluid collections, drainage of biliary and pancreatic ducts, and experimental tumor ablation techniques are discussed. For each topic, all current evidence has been extensively analyzed and summarized into major recommendations for reader consultation (short version; the long version is published online).

Feasibility study of EUS-NOTES as a novel approach for peroral cholecysto-gastrostomy.

BACKGROUND: EUS-guided cholecysto-gastrostomy might be a useful minimally invasive procedure used for salvage drainage in advanced pancreaticobiliary cancers, but also for drainage of the gallbladder in acute cholecystitis in patients deemed unfit for laparoscopic surgery. OBJECTIVE: Direct EUS-guided cholecysto-gastrostomy with placement of a double flanged expandable metal stents. DESIGN/SETTING: This was an animal pilot/feasibility study. INTERVENTIONS: The feasibility of EUS-guided cholecysto-gastrostomy through a transgastric approach was tested in five pigs. Specially designed EUS-guided devices for initial access in the gallbladder and a double flanged expandable metal stent were used in this study. RESULT: The results showed the feasibility of EUS-guided cholecysto-gastrostomy based on prototype devices for access in the gallbladder and transgastric stent placement. LIMITATIONS: Survival feasibility study with prototype devices in a small number of animals. CONCLUSIONS: EUS guided cholecysto-gastrostomy in a porcine model is feasible but technically demanding due to anatomical limitations of the pig and/or complexity of the procedure and the preliminary stage of development of the accessory devices. ABBREVIATIONS: NOTES - Natural Orifice Translumenal Endoscopic Surgery; EUS - Endoscopic Ultrasound; EUSFNA - Endoscopic Ultrasound Fine Needle Aspiration.

Contrast-enhanced harmonic endoscopic ultrasound.

Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most of the clinical applications include the differential diagnosis of focal pancreatic masses, with adenocarcinoma having a distinct hypovascular (hypo-enhanced) appearance compared with neuroendocrine tumors, which are hypervascular (with strong arterial hyper-enhancement). However, pseudotumoral chronic pancreatitis and autoimmune pancreatitis also have an iso- or hypervascular appearance, making the differential diagnosis difficult. Even more promising is the use of dynamic contrast-enhanced harmonic EUS for the longitudinal monitoring of the effects of chemotherapy and/or anti-angiogenic therapy in advanced digestive cancers, which are difficult to examine by conventional cross-sectional imaging techniques.

Reliable and valid assessment of competence in endoscopic ultrasonography and fine-needle aspiration for mediastinal staging of non-small cell lung cancer.

BACKGROUND AND STUDY AIMS: Fine-needle aspiration (FNA) guided by endoscopic ultrasonography (EUS) is important in mediastinal staging of non-small cell lung cancer (NSCLC). Training standards and implementation strategies of this technique are currently under discussion. The aim of this study was to explore the reliability and validity of a newly developed EUS Assessment Tool (EUSAT) designed to measure competence in EUS - FNA for mediastinal staging of NSCLC. PATIENTS AND METHODS: A total of 30 patients with proven or suspected NSCLC underwent EUS - FNA for mediastinal staging by three trainees and three experienced physicians. Their performances were assessed prospectively by three experts in EUS under direct observation and again 2 months later in a blinded fashion using digital video-recordings. Based on the assessments, intra-rater reliability, inter-rater reliability, and construct validity were explored. RESULTS: The intra-rater reliability was good (Cronbach's α = 0.80), but comparison of results based on direct observations and blinded video-recordings indicated a significant bias favoring consultants (P = 0.022). Inter-rater reliability was very good (Cronbach's α = 0.93). However, one rater assessing five procedures or two raters each assessing four procedures were necessary to secure a generalizability coefficient of 0.80. The assessment tool demonstrated construct validity by discriminating between trainees and experienced physicians (P = 0.034). CONCLUSIONS: Competency in mediastinal staging of NSCLC using EUS and EUS - FNA can be assessed in a reliable and valid way using the EUSAT assessment tool. Measuring and defining competency and training requirements could improve EUS quality and benefit patient care.

Nurse-administered propofol sedation for endoscopy: a risk analysis during an implementation phase.

BACKGROUND AND STUDY AIMS: The aim of the present study was to perform a risk analysis during the implementation phase of nurse-administered propofol sedation (NAPS) and to validate our structured training program. PATIENTS AND METHODS: A structured training program was developed both for endoscopists and for endoscopy nurses who were administering propofol sedation. The nurses' program comprised a 6-week course including theoretical and practical training in airway management, and the endoscopists' program consisted of 2.5 h of theory and a short course in practical airway management. In the implementation phase, data from 1822 endoscopic procedures in 1764 patients were prospectively collected. All adverse events related to sedation were recorded (defined as oxygen saturation < 92%, airway handling, assisted ventilation, need for intubation, change in blood pressure > 20 mmHg). RESULTS: 78 cases of hypoxemia were documented in 1764 patients (4.4%), in 56/983 upper endoscopies (5.7%) and 22/754 lower endoscopies (2.9%) (P = 0.007). Assisted ventilation was necessary in 19 cases (1.1%) and anesthesiologic assistance was requested 10 times. Two patients required endotracheal intubation. A change in blood pressure was recorded in 451 patients (26%). Independent risk factors were type of intervention and level of experience of the staff performing the sedation. CONCLUSION: These results were obtained after development of a structured training program both for endoscopists and nurses using propofol for sedation, and can be used as basis for further comparison. NAPS for endoscopic procedures is safe when performed by personnel properly trained in airway handling and sedation with propofol, and has considerable advantages compared with conventional sedation for endoscopy.

Indications, results, and clinical impact of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

This article is part of a combined publication that expresses the current view of the European Society of Gastrointestinal Endoscopy (ESGE) about endoscopic ultrasound (EUS)-guided sampling in gastroenterology, including EUS-guided fine needle aspiration (EUS-FNA) and EUS-guided trucut biopsy (EUS-TCB), of submucosal tumors, diffuse esophageal/gastric wall thickening, pancreatic solid masses and cystic-appearing lesions, mediastinal lesions unrelated to lung or esophageal cancer, cancer of the esophagus, stomach, and rectum, lymph nodes of unknown origin, adrenal gland masses, and focal liver lesions. False-positive cytopathological results and needle tract seeding are also discussed. The present Clinical Guideline describes the results of EUS-guided sampling in the different clinical settings, considers the role of this technique in patient management, and makes recommendations on circumstances that warrant its use. A two-page executive summary of evidence statements and recommendations is provided. A separate Technical Guideline describes the general technique of EUS-guided sampling, particular techniques to maximize the diagnostic yield depending on the nature of the target lesion, and sample processing. The target readership for the Clinical Guideline mostly includes gastroenterologists, oncologists, internists, and surgeons while the Technical Guideline should be most useful to endoscopists who perform EUS-guided sampling.

Accuracy of endoscopic ultrasound elastography used for differential diagnosis of focal pancreatic masses: a multicenter study.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound (EUS) elastography represents a new imaging procedure that might characterize the differences of hardness and strain between diseased tissue and normal tissue. The aim of this study was to assess the efficiency of EUS elastography for the differentiation of focal masses in chronic pancreatitis and pancreatic cancer. PATIENTS AND METHODS: The study group comprised 258 patients with focal pancreatic masses included prospectively at 13 participating centers. Qualitative analysis of the diagnoses made by two expert doctors using all recorded video clips was performed in order to test the interobserver variability. A post-processing software analysis was used to examine the EUS elastography videos by calculating average-hue histograms of individual elastography images. The quantitative information was used to calculate intra-observer variability and the accuracy of the method. RESULTS: Qualitative analysis of the recorded videos revealed a kappa value of 0.72. Intra-observer variability analysis revealed that the single measure intraclass correlation ranged between 0.86 and 0.94. The average-hue histogram analysis of the data indicated a sensitivity of 93.4 %, a specificity of 66.0 %, a positive predictive value of 92.5 %, a negative predictive value of 68.9 %, and an overall accuracy of 85.4 %, based on a cut-off value of 175. Area under the receiver operating characteristic curve (AUROC) was 0.854 ( P < 0.0001) with a confidence interval of 0.804 - 0.894. CONCLUSION: The value of quantitative analysis of EUS elastography recordings was proven by good reproducibility of the videos, as well as good parameters of the AUROC analysis. (Clinical Trials.gov identifier: CT00909103).

Endoscopic ultrasound-guided fine-needle aspiration cytology in the evaluation of suspected tuberculosis in patients with isolated mediastinal lymphadenopathy.

BACKGROUND AND STUDY AIMS: Patients with suspected tuberculosis without pulmonary lesions and with mediastinal lymphadenopathy often pose a diagnostic challenge. Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) cytology is an established modality to evaluate mediastinal and abdominal lesions. The aim of the present study was to evaluate the role of EUS-FNA in isolated mediastinal lymphadenopathy in patients suspected of having tuberculosis. METHODS: Consecutive patients suspected of having tuberculosis with isolated mediastinal lymphadenopathy were included in a prospective study. Mediastinal lymphadenopathy was diagnosed on a contrast-enhanced computed tomography scan of the chest. Patients with concomitant lung parenchymal lesions were excluded. Previous attempts to diagnose the etiology of lymphadenopathy had failed in 69 % of patients. EUS-FNA was performed on an outpatient basis under conscious sedation. The sensitivity, specificity, and diagnostic accuracy of EUS-FNA were calculated. RESULTS: A total of 60 consecutive patients (mean age 39.8 years, 58 % males) with mediastinal lymphadenopathy were included. EUS confirmed the presence of mediastinal lymph nodes ranging in size from 8 mm to 40 mm (mean 26 mm) in all patients. EUS-FNA provided an adequate tissue sample in 54 patients during the first examination and repeat EUS-FNA was necessary in six patients. A final diagnosis was obtained by EUS-FNA in 42 patients (tuberculosis in 32, sarcoidosis in six, and Hodgkin's disease in four patients). An additional 14 patients were treated for tuberculosis based on EUS-FNA and clinical features. Mediastinoscopy was required for diagnosis in the remaining four patients. EUS-FNA had an overall diagnostic yield of 93 %, sensitivity of 71 %, specificity of 100 %, and positive predictive value of 100 %. CONCLUSION: EUS-FNA is an accurate, safe, and minimally invasive modality for evaluating isolated mediastinal lymphadenopathy in patients suspected of having tuberculosis in an endemic area with a high prevalence of tuberculosis.

European Society of Gastrointestinal Endoscopy, European Society of Gastroenterology and Endoscopy Nurses and Associates, and the European Society of Anaesthesiology Guideline: Non-anesthesiologist administration of propofol for GI endoscopy.

Propofol sedation by non-anesthesiologists is an upcoming sedation regimen in several countries throughout Europe. Numerous studies have shown the efficacy and safety of this sedation regimen in gastrointestinal endoscopy. Nevertheless, this issue remains highly controversial. The aim of this evidence- and consensus-based set of guideline is to provide non-anesthesiologists with a comprehensive framework for propofol sedation during digestive endoscopy. This guideline results from a collaborative effort from representatives of the European Society of Gastrointestinal Endoscopy (ESGE), the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) and the European Society of Anaesthesiology (ESA). These three societies have endorsed the present guideline.

European Society of Gastrointestinal Endoscopy, European Society of Gastroenterology and Endoscopy Nurses and Associates, and the European Society of Anaesthesiology Guideline: Non-anaesthesiologist administration of propofol for GI endoscopy.

Propofol sedation by non-anaesthesiologists is an upcoming sedation regimen in several countries throughout Europe. Numerous studies have shown the efficacy and safety of this sedation regimen in gastrointestinal endoscopy. Nevertheless, this issue remains highly controversial. The aim of this evidence- and consensus-based set of guideline is to provide non-anaesthesiologists with a comprehensive framework for propofol sedation during digestive endoscopy. This guideline results from a collaborative effort from representatives of the European Society of Gastrointestinal Endoscopy (ESGE), the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA) and the European Society of Anaesthesiology (ESA). These three societies have endorsed the present guideline.The guideline is published simultaneously in the Journals Endoscopy and European Journal of Anaesthesiology.

A clinical evaluation of endoscopically placed self-expanding metallic stents in patients with acute large bowel obstruction.

BACKGROUND AND AIMS: Self-expanding metallic stents (SEMS) have since 1991 established themselves as an option in the treatment of large bowel obstruction. The aim of this study was to evaluate the use of SEMS in management of acute colorectal obstructions at a Danish Surgical Gastroenterology center. MATERIAL AND METHODS: Retrospective review of charts from all patients who, in the period Marts 2002 to December 2007 underwent insertion of a SEMS for an acute large bowel obstruction. RESULTS: Of 45 patients included, SEMS was intended as a bridge to surgery in 20 patients and as palliation in 25 patients. For malignant etiology, the SEMS procedure was a technical and clinical success in 97.4% of the cases. Complications occurred in 21%, mortality rate 2,6%. For benign etiology, the SEMS procedure was a technical success in 85.7%, and a clinical success in 71.4%. Complications occurred in 71.4% of the benign cases with a mortality rate of 28,6%. CONCLUSIONS: Placement of SEMS for acute large bowel obstruction with malignant etiology is an effective and safe procedure with low mortality and morbidity. However results for benign obstructions are questionable and more research is needed to determine the role of SEMS.

The complete ''medical'' mediastinoscopy (EUS-FNA + EBUS-TBNA).

Diagnosis of indeterminate mediastinal masses and staging of lung cancer poses a significant challenge. Options for tissue diagnoses include computed tomography (CT)-guided percutaneous biopsy, transbronchial fine-needle aspiration, mediastinoscopy/mediastinotomy or thoracoscopy, but these investigations have limitations in terms of tissue yield, safety profile and cost. Trans-esophageal endoscopic ultrasound scanning (EUS) is a new minimal invasive method that provides high resolution imaging of the mediastinum using high frequency ultrasound probes attached to the tip of a flexible endoscope and offers in addition the facility of fine needle aspiration (EUS-FNA) or tru-cut biopsy (TCB) under real-time ultrasound guidance. EUS-FNA allows access to the posterior mediastinum and tissue acquisition under real-time ultrasound guidance through the oesophageal wall. Indications of EUS-FNA in the mediastinum is to obtain a diagnosis from an unknown primary lesion or to sample tissue from mediastinal lymph nodes in order to stage lung cancer or to diagnose other diseases involving lymph nodes of the mediastinum eg. TB, Sarcoidosis, histoplasmosis or metastases from a vide range of cancers. If lymphoma is suspected EUS-TCB of an enlarged mediastinal lymph node is preferred. EUS- FNA is safe, can be done on an outpatient basis, is well tolerated and provides an excellent diagnostic yield with a sensitivity of more than 90% and a specificity of 100%. Compared to CT, PET, mediastinoscopy as well as transbronchial aspiration, EUS-FNA is found to be significant more accurate for staging of non-small cell lung cancer. However, mediastinoscopy is at present still regarded as the gold standard in the region of the anterior mediastinum since EUS can not image this region due to the air-filled trachea. Recently, endobronchial ultrasound guided transbronchial needle aspiration Biopsy (EBUS-TBNA) has been developed and several publications have now documented high diagnostic values with sensitivities of more than 90% in the staging of NSCLC. A recent publication from our group has documented a sensitivity and specificity of 100% when EUS-FNA and EBUS-TBNA is used in combination for staging of the mediastinum. It seems therefore logical to assume that the combination of EUS-FNA and EBUS-TBNA will replace more invasive methods such as mediastinoscopy for diagnosis and staging of lung cancers in the near future.

Transesophageal endoscopic ultrasound/fine-needle aspiration diagnosis of a malignant adrenal gland in a patient with non-small cell lung cancer and a negative CT scan.

Adrenal metastasis is only seen on CT scan is less than 5% of patients with otherwise resectable NSCLS, but this diagnosis has a major impact on treatment and prognosis. We present a case of a patient with NSCLC and an adrenal metastasis, which was diagnosed by EUS/FNA of an enlarged adrenal gland, who had false-negative CT scan for adrenal metastasis. PET was not performed. Prospective studies are needed to assess the incremental yield of EUS/FNA over upper abdominal CT scan and PET for detecting left adrenal metastasis in patients with suspected or proven otherwise respectable NSCLC.

Endoscopic ultrasonography and real-time guided fine-needle aspiration biopsy of solid lesions of the mediastinum suspected of malignancy.

STUDY OBJECTIVE: The study details our preliminary experience with endoscopic ultrasonography (EUS) guided fine-needle aspiration biopsy (FNAB) of mediastinal masses suspected of malignancy. DESIGN: Prospective uncontrolled study. PATIENTS: Nine patients had lesions suspected of malignancy ranging from 1 to 9 cm in diameter in various locations of the mediastinum. INTERVENTIONS: The EUS examination was performed with a gastroscope (Hitachi/Pentax FG-32 UA) equipped with an adjustable 5- or 7.5-MHz curved array ultrasonic transducer. The scanning plane is in the long axis of the endoscope allowing endosonographically guided biopsy to be performed. A 21-gauge (0.8 mm), full-length steel needle housed in a biopsy handle (type: Hancke/Vilmann; GIP-Medizin Technik; Grassau, Germany) was used for the biopsies. RESULTS: Nine patients had biopsy specimens taken from 13 lesions. The total number of needle passes was 18 (range, 1 to 3; median, 1.4). The cytologic diagnosis was conclusive for cancer in ten lesions and consistent with a benign lesion in three lesions. All ten malignant diagnoses and two benign diagnoses were confirmed either by operation or follow-up. In the last patient with lung cancer, a final diagnosis of the EUS-guided biopsy of an enlarged lymph node could not be obtained. No false-positive or negative biopsy diagnoses were recorded. The biopsy procedure was well tolerated by all patients, and there were no complications. CONCLUSIONS: EUS-guided aspiration biopsy is a significant advance in the differentiation between malignant and benign lesions of the mediastinum carrying a high diagnostic potential.