Endoscopic ultrasound-guided fine-needle aspiration biopsy for the diagnosis of gastrointestinal stromal tumors in the stomach

Background For the diagnosis of gastric submucosal tumors (SMTs), endoscopic ultrasound (EUS) alone does not reveal the complete pathology, such as the degree of malignancy, and EUS-guided fine-needle aspiration biopsy (EUS-FNAB) has been reported to be more useful. Recently, most cases initially diagnosed as leiomyosarcomas have received further study with immunohistochemical staining and have been given the new diagnosis of gastrointestinal stromal tumors (GISTs). The degree of malignancy of GISTs differs widely in clinical aspects. In this study, we examined whether EUS-FNAB was useful in diagnosing GISTs and differentiating their degrees of malignancy.Methods From January 1997 to March 2002, 21 cases of gastric GISTs were diagnosed from the immunohistochemical staining of specimens resected at Aichi Cancer Center Hospital. Of these 21 patients, 14 (5 with high-grade malignancy and 9 with low-grade malignancy) underwent EUS-FNAB preoperatively, and were examined further: their EUS-FNAB specimens were submitted for additional immunohistochemical testing.Results The EUS-FNAB specimens from all patients were positive for c-kit and CD34 immunohistochemical testing, coinciding with the staining results of the resected specimens. The MIB-1 labeling indices in specimens of high-grade malignancy were significantly higher than those of low-grade malignancy. If we assumed that a tumor with an MIB-1 labeling index of more than 5% was a high-grade malignancy, the diagnostic accuracy was 85.7%.Conclusions The EUS-FNAB procedure is a useful tool for diagnosing GISTs of the stomach with immunohistochemical staining. When used with MIB-1 staining, the procedure may indicate GIST prognosis and influence decisions regarding therapeutic strategies.     

EUS-guided fine needle aspiration in mediastinal lymphadenopathy of unknown etiology

BACKGROUND: EUS-guided fine needle aspiration (EUS-FNA) has significantly expanded the diagnostic capability of GI EUS. FNA technology can also be helpful in the diagnosis of non-GI disorders. The role of EUS-guided FNA in the diagnosis of mediastinal lymphadenopathy of unknown etiology has not been described. The aim of this study was to evaluate the diagnostic accuracy and impact on subsequent evaluation and therapy of EUS-FNA in mediastinal lymphadenopathy of unknown cause. METHODS: Sixty-two patients (40 men, 22 woman; mean age 56 years, range 16-91 years) with mediastinal lymphadenopathy of unknown etiology underwent EUS-FNA at 6 tertiary referral centers. Presenting symptoms included the following: dysphagia, 6 patients; night sweats, 14; cough, 8; chest pain, 10; odynophagia, 10; fever, 6; weight loss, 8; and asymptomatic/abnormal radiograph, 12. A final diagnosis by EUS-FNA, surgery, autopsy, or long-term follow-up was available for all patients. EUS-FNA results were classified under 3 disease categories: (1) benign/infectious; (2) malignant pulmonary; and (3) malignant mediastinal (e.g., lymphoma, metastatic malignancy). Four EUS features were used as criteria for lymph node metastases: size greater than 1 cm, round shape, sharp border, and homogeneous/hypoechoic echo pattern. RESULTS: Final diagnoses included benign/infectious lymph nodes, 26; malignant pulmonary, 24; and malignant mediastinal, 12. EUS-FNA established a tissue diagnosis in 56 of 62 patients (90%). EUS criteria for malignant lymph nodes were more frequently present in malignant pulmonary (mean 2.6 features) and malignant mediastinal (mean 2.8) than benign/infectious (mean 1.9) lymph nodes. EUS results influenced subsequent evaluation in 87% and therapy in 87% of patients. There was no complication of EUS-FNA. CONCLUSIONS: EUS-FNA in patients with mediastinal lymphadenopathy is safe and guides subsequent therapy in the great majority of cases. Transesophageal EUS-FNA of mediastinal lymph nodes provides minimally invasive tissue sampling, obviating the need for mediastinoscopy or bronchoscopy.     

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

AIM： to evaluate the role of endoscopic ultrasonographyguided fine needle aspiration （EUS-FNA） in the preoperative diagnosis of gastrointestinal stromal tumor （GIST）.
METHODS： From September 2002 to June 2006, Fiftythree consecutive EUS-FNAs of GI tract subepithelial hypoechoic tumors with continuity to proper muscle layer suspected as GIST by standard EUS were evaluated prospectively. The reference standards for the final diagnosis were surgery （n = 31）, or clinical follow-up （n = 22）. Additionally, immunophenotyping of specimens obtained by EUS-FNA and surgical resection specimens were compared.
RESULTS： In 2 cases puncture was not performed because of anatomical problems. The collection rate of adequate specimens from the GI tract subepithelial hypoechoic tumor with continuity to proper muscle layer was 82% （42/51）. The diagnostic rate for the tumor less than 2 cm, 2 to 4 cm, and 4 cm or more were 71% （15/21）, 86% （18/21）, and 100% （9/9）,respectively. In 29 surgically resected cases, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of EUS-FNA using immunohistochemical analysis of GIST were 100%（24/24）, 80% （4/5）, 96% （24/25）, 100% （4/4）, and 97% （28/29）, respectively. No major complications were encountered.
CONCLUSION： EUS-FNA with immunohistochemical analysis is a safe and accurate method in the pretherapeutic diagnosis of GIST. It should be taken into consideration in decision making, especially in early diagnosis following minimal invasive surgery for GIST.     

Gastric GIST malignancy evaluated by 18FDG-PET as compared with EUS-FNA and endoscopic biopsy

OBJECTIVE: The usefulness of 18F-fluoro-2-deoxyglucose positron emission tomography (18FDG-PET), whose high rate of FDG accumulation indicates high metabolism and malignant potential, has already been reported. The aims of this study were to evaluate the malignancy of primary gastrointestinal stromal tumour (GIST) in the stomach by 18FDG-PET and to correlate the FDG uptake values with known risk factors as determined by histology after EUS-guided fine needle aspiration (EUS-FNA) or endoscopic biopsy. MATERIAL AND METHODS: Of 29 patients with histologically proven GI-mesenchymal tumours, 21 with gastric GISTs underwent 18FDG-PET. Tumour size, mitotic index, Ki-67 labelling index (LI) and cellularity of the tumour tissue were compared with the standardized uptake value (SUV) of FDG. RESULTS: Strong correlations were found between the SUV of FDG and EUS size, and mitotic index of EUS-FNA specimens (tumour size versus SUV, p=0.004, r=0.542; number of mitotic cells versus SUV, p=0.0078; n=21). Moreover, we examined the association between SUV and risk categories based on EUS-FNA findings using ROC curves. The cut-off values of FDG SUV were 2.2, 4.2 and 6.5 for the very low-, low-, intermediate- and high-risk groups, respectively. CONCLUSIONS: 18FDG-PET may be used to assess malignancy of GISTs. This image modality helps us determine the management strategy for these patients and complements the information on the biological behaviour and cellular proliferation of the tumours.     

Endosonographic large-bore biopsy of gastric subepithelial tumors: a prospective multicenter study

BACKGROUND: Once gastric subepithelial lesions (SEL) are found, tissue diagnosis is required, considering the possible differential diagnosis of gastrointestinal stromal tumors (GIST). Previous studies have shown insufficient accuracy of endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using cytologic analysis. METHODS: The feasibility and yield of EUS-FNA-based histologic tissue acquisition for gastric SEL, using 19 G large-bore needles, was assessed in a 4-year multicenter, prospective study. All consecutive patients, who were referred for EUS-FNA for all SEL greater than 1 cm, were included. RESULTS: Of 100 patients with suspected gastric SEL, 71 lesions were found to be eligible. Endoscopic biopsies or resections or surgery were used alternatively for a variety of reasons in 25 patients. EUS-FNA using the 19 G needle was finally performed in 46/71 cases (65%) with one to four needle passes. Sufficient material for a definite or a suspected histological diagnosis was obtained in 52 and 7% of the cases, respectively. In 41%, the samples were not informative. Immunohistochemistry was possible in 91% of cases with sufficient amounts of tissue; 30% were GIST. Self-limited, mild hemorrhage occurred in 22%; one patient developed a fatal abscess. CONCLUSION: Even when intended, EUS-guided 19 G FNA is only feasible in 46% of gastric SEL. The diagnostic yield of 19 G FNA was only 52%, but with excellent differentiation between GIST and leiomyoma. Infectious complications must be prevented.     

Endoscopic ultrasonography for gastric submucosal lesions

Gastric submucosal tumors(SMTs) are a rather frequent finding,occurring in about 0.36%of routine upper GIendoscopies.Endoscopic ultrasonography(EUS) has emerged as a reliable investigative procedure for evaluation of these lesions.Diagnostic EUS has the ability to differentiate intramural tumors from extraluminal compressions and can also show the layer of origin of gastric SMTs.Tumors can be further characterized by their layer of origin,echo pattern and margin.EUS-risk criteria of their malignant potential are presented,although the emergence of EUS-FNA has opened new indications for transmural tissue diagnosis and expanded the possibilities of EUS in SMTs of the stomach.Tissue diagnosis should address whether the SMT is a Gastrointestinal stromal tumour(GIST) or another tumor type and evaluate the malignant potential of a given GIST.However,there seems to be a lack of data on the optimal strategy in SMTs suspected to be GISTs with a negative EUS-FNA tissue diagnosis.The current management strategies,as well as open questions regarding their treatment are also presented.     

Impact of EUS-guided fine-needle aspiration on lymph node staging in patients with esophageal carcinoma

BACKGROUND: Preoperative identification of lymph node metastases associated with esophageal carcinoma may influence treatment. EUS is the most accurate method for locoregional staging of these tumors. The impact of EUS-guided fine-needle aspiration (EUS-FNA) on lymph node staging in esophageal carcinoma is unclear. METHODS: From May 1996 to May 1999, 74 patients with esophageal carcinoma underwent preoperative EUS. After October 1998 EUS-guided FNA was performed on nonperitumoral lymph nodes greater than 5 mm in width. The results of EUS with and without FNA were retrospectively reviewed and compared. Final diagnosis was based on surgical results or EUS-guided FNA malignant cytology. Ten of the 74 patients had to be excluded for lack of lymph node stage confirmation. Final diagnosis was obtained in the remaining 64 patients (33 from the EUS only group and 31 from the EUS-FNA group). RESULTS: The results of EUS versus EUS-FNA for lymph node staging were sensitivity 63% versus 93% (p = 0.01), specificity 81% versus 100% (not significant), and accuracy 70% versus 93% (p = 0.02), respectively. Complications comprised 1 patient who developed self-limited bleeding after dilation that did not preclude completion of the EUS (1%, 95% CI [0%, 7%]). CONCLUSIONS: EUS-FNA is more sensitive and accurate than EUS alone for preoperative staging of locoregional and celiac lymph nodes associated with esophageal carcinoma. EUS-FNA of nonperitumoral lymph nodes in patients with esophageal carcinoma is safe and should be routinely performed when treatment decisions will be affected by nodal stage.     

Endoscopic ultrasound-guided fine-needle aspiration for diagnosing a rare extraluminal duodenal gastrointestinal tumor

Duodenal gastrointestinal stromal tumors(GISTs) are extremely rare disease entities, and the extraluminal type is difficult to diagnose. These tumors have been misdiagnosed as pancreatic tumors; hence, pancreaticoduodenectomy has been performed, although partial duodenectomy can be performed if accurately diagnosed. Developing a diagnostic methodology including endoscopic ultrasonography(EUS) and fine-needle aspiration(FNA) has allowed us to diagnose the tumor directly through the duodenum. Here, we present a case of a 50-year-old woman with a 27-mm diameter tumor in the pancreatic uncus on computed tomography scan. EUS showed a well-defined hypoechoic mass in the pancreatic uncus that connected to the duodenal proper muscular layer and was followed by endoscopic ultrasoundguided fine-needle aspiration(EUS-FNA). Histological examination showed spindle-shaped tumor cells positively stained for c-kit. Based on these findings, the tumor was finally diagnosed as a duodenal GIST of the extraluminal type, and the patient underwent successful mass resection with partial resection of the duodenum. This case suggests that EUS and EUS-FNA are effective for diagnosing the extraluminal type of duodenal GISTs, which is difficult to differentiate from pancreatic head tumor, and for performing the correct surgical procedure.     

内镜超声引导下细针穿刺结合免疫组织化学鉴别上消化道固有肌层肿瘤

目的探讨内镜超声引导下细针穿刺结合免疫组织化学检查在鉴别上消化道固有肌层肿瘤起源中的作用。方法选择经内镜发现并由内镜超声检查证实直径大于25mm的上消化道固有肌层病变患者35例，内镜超声检查明确病变的大小、形态、位置，并观察有无周围脏器转移。在内镜超声导引下对病变行细针穿刺，对取材分别进行HE、CD117，CD34和肌动蛋白（SMA）染色。结果35例患者中，31例患者取得了足够的组织，经免疫组化染色，诊断为间质瘤21例，平滑肌瘤10例。与术后诊断比较超声内镜结合免疫组织化学检查的敏感性为88．6％，特异性为100％。无一例患者出现不良反应。结论内镜超声引导下细针穿刺结合免疫组织化学检查是鉴别上消化道固有肌层肿瘤安全有效的方法。     

胃黏膜下肿瘤黏膜切开活检的临床回顾性研究

目的比较黏膜切开活检(mucosal cutting biopsy，MCB)与内镜超声引导下细针抽吸术(endoscopic ultrasound-guided-fine needle aspiration，EUS-FNA)这两种方法对胃黏膜下肿瘤(submucosal tumors，SMTs)的组织病理诊断效率。方法选取2017年9月—2019年12月上海市第六人民医院金山分院消化内镜中心收治的40例SMTs患者。参照日本胃肠间质瘤诊疗指南，原则上以EUS-FNA作为首选诊断方法。如果EUS-FNA取样组织病理诊断不充分或技术不适宜，则采取MCB补充取样。回顾性分析这些患者的临床病理资料，比较MCB与EUS-FNA的病理诊断效率。结果全部40例SMTs患者采用MCB和（或）EUS-FNA方法得到确诊。其中9例单独采用MCB方法诊断，24例单独采用EUS-FNA诊断，另外7例采用EUS-FNA、MCB联合诊断。因此，共16例患者采用MCB，31例采用EUS-FNA。MCB与EUS-FNA操作时间差异无统计学意义[（40.5±14.7）min比（45.2±19.3）min，t=0.853，P=0.398]。两组总体病理诊断率差异无统计学意义[87.5%（14/16）比80.6%（25/31）， χ2=0.351，P=0.553]。两组各有2例异位胰腺无需免疫组化，其他病变免疫组化诊断率差异有统计学意义[92.9%（13/14）比58.6%（17/29），χ2=5.247,P=0.022]。结论MCB比EUS-FNA具有更好的免疫组化诊断率，是诊断胃SMTs有效的方法。     

A descriptive analysis of EUS-FNA for mediastinal lymphadenopathy: an emphasis on clinical impact and false negative results

OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been shown to accurately diagnose mediastinal lymph node pathology. We investigated the clinical impact of EUS-FNA in the management of patients with mediastinal lymphadenopathy, and determined the nature and clinical consequences of false negative results. METHODS: We analyzed a cohort of patients who were found to have mediastinal lymph nodes by EUS and underwent FNA. The diagnostic standard included FNA cytology, histopathology, and clinical follow-up. RESULTS: Sixty EUS-FNAs of mediastinal lymph nodes were performed on 59 patients (mean age 61 years old, 74.5% men) over a 24-month period. Prior to EUS, 20 (34%) patients had known malignancy. The most frequent indication for EUS was failed diagnosis by bronchoscopy (54%). EUS-FNA of lymph nodes showed malignant cells in 38%. The diagnostic accuracy of EUS-FNA was 84%. Among the 47 patients who were available for follow-up, EUS-FNA provided new information by changing the clinical diagnosis, and subsequently changed the management in 18 (38%) patients. The false negative rate was 20% (95% exact CI, 8.4-31.6%). Two of the 7 false negative cases received empiric chemoradiation without tissue diagnosis, and 4 received palliative treatment for advanced malignancy. CONCLUSION: The most common indication for EUS-FNA of the mediastinum in our institution is nondiagnostic transbronchial FNA. EUS-FNA is a valuable diagnostic method for sampling mediastinal lymph nodes and affecting management. False negative results do not appear to delay appropriate treatment or adversely affect clinical outcome.     

Influence of EUS training and pathology interpretation on accuracy of EUS-guided fine needle aspiration of pancreatic masses

BACKGROUND: Identification, staging, and fine needle aspiration of pancreatic mass lesions are probably the most technically demanding EUS skills. This study evaluated the effect of formal training on the diagnostic accuracy of EUS-guided fine needle aspiration (EUS-FNA) of pancreatic masses and the source of the variability in diagnostic accuracy between initial and later procedures. METHODS: Sixty-five patients with pancreatic masses underwent EUS-FNA between April 1998 (introduction of EUS-FNA) and August 1999, 20 of whom were examined by 3 endosonographers without prior experience with EUS-FNA. The initial experience of these 3 endosonographers (April to December 1998; group A patients), which included a formal training period of 2 months, and their later experience (January to August 1999; group B patients) were evaluated. Final diagnoses were determined by surgical pathology or clinical follow-up. All EUS-FNA samples were reviewed by 4 blinded pathologists to determine the contribution of pathologist interpretation to varying EUS-FNA accuracy. RESULTS: After a short training period, there was a significant improvement in EUS-FNA accuracy (33% vs. 91%; p = 0.004). After pathology review, good agreement was identified between original FNA interpretation and that on review (kappa = 0.78; 95% CI [0.5, 1.0]). There were differences between the mean cellularity score (2.8 vs. 1.8, p = 0.01) and mean number of passes (5.1 vs. 2.8, not significant) for correct versus incorrect FNA specimens. CONCLUSION: Significant improvements in EUS-FNA accuracy can be achieved with a short period of mentored training. EUS-FNA errors during the initial learning phase are primarily due to inadequate specimens. Interpretation of pancreatic EUS-FNA specimens remained consistent before and after training.     

Esophageal endoscopic ultrasound with fine-needle aspiration with an on-site cytopathologist: high accuracy for the diagnosis of mediastinal lymphadenopathy

STUDY OBJECTIVES: To analyze the accuracy of esophageal endoscopic ultrasound (EUS) with real-time, guided fine-needle aspiration (EUS-FNA) with an on-site cytopathologist in patients with (presumed) lung cancer presenting with mediastinal lymphadenopathy (ML) or a suspect left adrenal gland (LAG). DESIGN: A single-center prospective study. PATIENTS: Sixty-seven outpatients with (presumed) lung cancer with ML or a suspect LAG on either CT and/or positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) scan. INTERVENTIONS: All patients underwent EUS-FNA under conscious sedation. A cytopathologist was present during all procedures. MEASUREMENTS: EUS with and without fine-needle aspiration (FNA) as compared to FDG-PET was evaluated for accuracy in diagnosing cancer, safety, and rate of avoidance for further surgery. RESULTS: Of 67 consecutive patients (56 men; median age, 64 years), malignant ML or LAG were found in 47 patients (70.1%). In 20 patients (29.9%) without EUS-FNA proof of malignancy, confirmation was obtained by surgical procedure in 13 patients (sarcoidosis [n = 5], infection [n = 1], lung cancer [n = 7]) or by clinical follow-up in 5 patients suggesting benign disease. Sixty-five patients were included in the calculation of test characteristics. With malignancy as an end point, the accuracy for EUS-FNA was 100%. This was better than EUS without FNA (accuracy, 75.4%; p < 0.001) or FDG-PET (accuracy, 75.0% [n = 28]; p = 0.0011). When using final histopathologic diagnosis as an end point, the accuracy of EUS-FNA was 92.3%, since EUS-FNA was unable to show noncaseating granulomas in those patients with sarcoidosis diagnosed after mediastinoscopy. Related to the presence of the in situ cytopathologist, there were no inconclusive samples. No adverse events were recorded, and 67.7% of surgical interventions were avoided following EUS-FNA. CONCLUSIONS: The accuracy in this series of EUS-FNA with cytopathologist-assisted rapid on-site evaluation is high. The technique is safe and greatly reduces the number of surgical interventions.     

265例胃肠道间叶源性肿瘤的临床病理特征及超声内镜诊断价值

目的探讨胃肠道间叶源性肿瘤（gastrointestinal mesenchymal tumor,GIMT）的临床病理特征及超声内镜（edoscopic ultrasonography,EUS）的诊断价值.方法观察265例GIMT病理特征并检测CD117、CD34、平滑肌肌动蛋白（SMA）、S-100、Ki-67等抗体的表达情况,确诊后回顾其中32例术前EUS检查结果.结果 265例GIMT中胃肠道间质瘤（gastrointestinal stromal tumor,GIST）146例,平滑肌（肉）瘤（leiomyoma or leiomyosarcoma）113例,神经源性肿瘤6例.免疫组化结果：GIST以CD117阳性132/146（90.4%）和CD34阳性109/146（74.7%）为主,SMA和S-100分别在平滑肌（肉）瘤和神经鞘膜瘤中强阳性表达,9例GIST中7例Ki-67阳性且伴较多有丝分裂,病理诊断为交界性或恶性GIST.交界性、恶性GIST多见于男性患者.EUS对GIST、平滑肌瘤的定位准确率为96.9%,诊断准确率84.4%,良恶性鉴别准确率71.9%.结论 GIMT主要为GIST.形态上类似的GIST与平滑肌瘤及神经鞘膜瘤区别可用CD117、CD34、SMA、S-100等多种免疫组化标记物.联用Ki-67表达和有丝分裂数判断间质瘤的良恶性的敏感性、特异性高.EUS对于GIMT的诊断及良恶性鉴别有一定的应用价值,结合EUS引导下细针穿刺（EUS-FNA）活检是未来的诊断选择.     

The utility and the safety of EUS-guided FNA in the evaluation of duplication cysts

BACKGROUND: Diagnosis of a foregut duplication cyst is of great clinical impact. A definitive diagnosis of a foregut duplication cyst can avert the need for major thoracic surgery in the otherwise asymptomatic individual. This study sought to evaluate the safety and the utility of EUS and EUS-guided FNA (EUS-FNA) in the diagnosis of foregut duplication cysts. METHODS: Over a period of 4 years, 4771 patients underwent EUS for various indications at two EUS referral centers. EUS findings were consistent with a mediastinal cyst in 30 cases. EUS-FNA was performed in 22 patients. A definitive diagnosis was established based on cytology, surgical pathology, and/or clinical follow-up. FNA was done with 22-gauge needles and antibiotic prophylaxis. RESULTS: The appearance of cyst contents on EUS ranged from completely anechoic (23 cases) to hypoechoic (7 cases). Hypoechoic cystic lesions contained echogenic foci. All anechoic lesions were confirmed as benign duplication cysts based on cytology, pathology, and clinical follow-up. Hypoechoic cystic lesions were confirmed to be benign duplication cysts in 4 cases. Three cases proved to be malignant or granulomatous necrotizing lymph nodes. No periprocedural complications occurred. CONCLUSIONS: Variation exists in the EUS appearance of benign mediastinal cysts. EUS-FNA of mediastinal cysts with smaller-gauge needles, and antibiotic prophylaxis appears safe and can provide a definitive diagnosis in atypical mediastinal cystic lesions.     

Predictors of malignancy and recommended follow-up for patients with negative endoscopic ultrasound-guided fine-needle aspiration of suspected pancreatic lesions

BACKGROUND:

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) can characterize and diagnose pancreatic lesions as malignant, but cannot definitively rule out the presence of malignancy. Outcome data regarding the length of follow-up in patients with negative or nondiagnostic EUS-FNA of pancreatic lesions are not well-established.

OBJECTIVE:

To determine the long-term outcome and provide follow-up guidance for patients with negative EUS-FNA diagnosis of suspected pancreatic lesions based on imaging predictors.

METHODS:

A retrospective review of patients undergoing EUS-FNA for suspected pancreatic lesions, but with negative or nondiagnostic FNA results was conducted at a tertiary care referral medical centre. Patient demographics, EUS imaging characteristics and follow-up data were examined.

RESULTS:

Seventeen of 55 patients (30.9%) with negative/nondiagnostic FNA were subsequently diagnosed with pancreatic malignancy. The risk of cancer was significantly higher for patients who had associated lymph nodes on EUS (P<0.001) and vascular involvement on EUS (P=0.001). The mean time to diagnosis in the group with false-negative EUS-FNA diagnosis was 66 days. The true-negative EUS-FNA patients were followed for a mean of 403 days after negative EUS-FNA results without the development of malignancy.

CONCLUSION:

For patients undergoing EUS-FNA for a suspected pancreatic lesion, a negative or nondiagnostic FNA does not provide conclusive evidence for the absence of cancer. Patients for whom vascular invasion and lymphadenopathy are detected on EUS are more likely to have a true malignant lesion and should be followed closely. When a patient has been monitored for six months or more with no cancer being diagnosed, there appears to be much less chance that a pancreatic malignancy is present.     

EUS-guided fine needle aspiration of the liver: indications,yield, and safety based on an international survey of 167 cases

BACKGROUND: The liver is a common site of metastases for various malignancies. EUS-guided fine needle aspiration (EUS-FNA) of liver masses has only been reported in small series from single centers. METHODS: A retrospective questionnaire was sent by e-mail to 130 EUS-FNA centers around the world regarding indications, complications, and findings of EUS-FNA of the liver. RESULTS: Twenty-one centers reported 167 cases of EUS-FNA of the liver. A complication was reported in 6 (4%) of 167 cases including the following: death in 1 patient with an occluding biliary stent and biliary sepsis, bleeding (1), fever (2), and pain (2). EUS-FNA diagnosed malignancy in 23 of 26 (89%) cases after nondiagnostic fine needle aspiration under transabdominal US guidance. EUS localized an unrecognized primary tumor in 17 of 33 (52%) cases in which CT had demonstrated only liver metastases. EUS image characteristics were not predictive of malignant versus benign lesions. CONCLUSION: EUS-guided FNA of the liver appears to be a safe procedure with a major complication rate of approximately 1%. EUS-FNA should be considered when a liver lesion is poorly accessible to US-, or CT-guided FNA should be considered when US- or CT-guided FNA fail to make a diagnosis, when a liver lesion(s) is detected (de novo) by EUS, and for investigation of possible upper GI primary tumors in the setting of liver metastases.     

EUS-guided FNA of regional lymph nodes in patients with unresectable hilar cholangiocarcinoma

BACKGROUND: The clinical impact of EUS-guided FNA (EUS-FNA) in regional lymph-node staging in patients with unresectable hilar cholangiocarcinoma before liver transplantation has yet to be determined. OBJECTIVES: To determine the frequency of regional lymph-node detection, identify EUS features predictive of benign or malignant lymph nodes, compare EUS lymph-node detection rates to CT/magnetic resonance imaging and exploratory laparotomy, and evaluate the impact of EUS-FNA on patient selection for liver transplantation. DESIGN: Retrospective case series. SETTING: Tertiary referral EUS unit. PATIENTS: Clinical, radiographic, EUS, cytologic, and surgical data of 47 patients with unresectable hilar cholangiocarcinoma before liver transplantation were evaluated. INTERVENTIONS: EUS-FNA. MAIN OUTCOME MEASUREMENTS: Lymph-node morphology and echo features. RESULTS: EUS identified lymph nodes in all patients. FNA of 70 lymph nodes identified metastases in 9 nodes of 8 patients (17%), who were then precluded from transplantation before a staging laparotomy. Identified lymph nodes, irrespective of malignant involvement, were typically oval and geographic in shape, of mixed echogenicity, with a hypoechoic border. There were no morphologic criteria or echo features to correlate with nodal malignancy. The EUS finding of absent regional lymph-node metastases was confirmed in 20 of 22 by a subsequent exploratory staging laparotomy. LIMITATIONS: Single institution, retrospective analysis. CONCLUSIONS: EUS identified lymph nodes in all patients, and confirmation of malignant lymph nodes detected by FNA precluded 17% of patients from transplantation. EUS-FNA of visualized lymph nodes irrespective of appearance is advised because morphology and echo features do not predict malignant involvement.     

EUS-guided fine needle aspiration of idiopathic abdominal masses

BACKGROUND: EUS-guided fine needle aspiration (EUS-FNA) has significantly increased the diagnostic capability of EUS. FNA can also be helpful in the diagnosis of non-GI disorders. The role of EUS-FNA in the diagnosis of idiopathic abdominal masses has not been determined. This study evaluated the diagnostic accuracy of EUS-FNA of abdominal masses of unknown cause and its impact on subsequent evaluation and therapy. METHODS: Thirty-four patients from 5 tertiary referral centers (21 women, 13 men; mean age 54 years, range 27-72 years) with idiopathic abdominal masses underwent EUS-FNA. Presenting symptoms included the following: pain (29 patients), weight loss (15), altered bowel habits (7), nausea/vomiting (6), abnormal liver function tests (4), palpable mass (4), and urinary retention (1). Four patients had a history of intra-abdominal cancer (2 cervical, 1 ovarian, 1 colon). A final diagnosis by EUS-FNA, surgery, autopsy, or long-term follow-up was available in all patients. Abdominal masses were classified into 3 disease categories: infectious, benign/inflammatory, and malignant. RESULTS: Final diagnosis included infectious (5), benign/inflammatory (6), and malignant (23) abdominal mass. Overall, EUS-FNA established a tissue diagnosis in 29 of 34 patients (85%) in all 3 categories (infectious, 80%; benign/inflammatory, 67%; malignant, 91%). EUS-FNA was instrumental in directing subsequent evaluation in 29 patients (85%) and therapy in 26 (77%). The number of fine needle passes for adequate tissue sampling was lower for nonmalignant (2.2-3.2) versus malignant diseases (4.6). One complication occurred (perirectal abscess) and was treated successfully with antibiotics. CONCLUSIONS: EUS-FNA of idiopathic abdominal masses is safe and accurate and helps to guide subsequent evaluation and therapy in the majority of patients. The most common and promising area seems to be EUS-FNA of malignant abdominal masses. Transluminal EUS-FNA provides minimally invasive tissue sampling and obviates the need for exploratory laparotomy.     

EUS-guided fine needle tissue acquisition by using high negative pressure suction for the evaluation of solid masses: a pilot study

BACKGROUND: The capability of obtaining tissue samples for histologic examination during EUS has theoretical advantages over cytology alone. The objective was to evaluate the feasibility and the yield of EUS-guided FNA tissue acquisition (EUS-FNTA) by using high negative pressure suction. METHODS: The study design is a prospective, observational pilot study set at a tertiary referral center. Twenty-seven patients with a solid mass amenable to sampling with EUS were included in the study. FNA with a 22-gauge needle was used for a total of 5 passes. An additional pass with the same needle was performed by applying continuous high negative pressure suction using the Alliance II inflation system. The main outcome measurements were the rate of tissue acquisition and the diagnostic accuracy of EUS-FNTA. OBSERVATIONS: Tissue samples were obtained in 26 of the 27 patients (96%). Malignancy was detected in 20 of the 26 biopsy specimens obtained by FNTA and in 20 of the 27 FNA specimens. In 3 patients, EUS-FNTA failed to disclose malignancy, which in two of the patients was diagnosed by FNA. Conversely, EUS-FNTA diagnosed a recurrent malignant thymoma and a schwannoma in two FNA-negative patients. In 3 patients with both FNTA and FNA negative for malignancy, a definitive diagnosis could not be established. Overall, diagnostic accuracy was 76.9% for both EUS-FNTA and EUS-FNA. When combined, a correct diagnosis was achieved in 84.6% of the patients. Immunostaining of the retrieved tissue allowed characterization of the primary tumor in 5 cases and the diagnosis of a schwannoma and two neuroendocrine tumors. Limitations of the study were small sample size and a pilot study. CONCLUSIONS: EUS-FNTA has a high yield for the retrieval of core tissue samples. Further studies in which EUS-FNTA is performed before FNA and with variable number of passes are needed to better define its diagnostic role and performance characteristics.