Factors affecting the diagnostic accuracy of endoscopic ultrasonography‐guided fine‐needle aspiration (EUS‐FNA) for upper gastrointestinal submucosal or extraluminal solid mass lesions

Aim: A number of potential variables are associated with the diagnostic accuracy of endoscopic ultrasonography‐guided fine‐needle aspiration (EUS‐FNA). The aim of this study was to evaluate factors affecting the diagnostic accuracy of EUS‐FNA for upper gastrointestinal submucosal or extraluminal solid lesions. Methods: Patients with such lesions who underwent EUS‐FNA between January 2009 and December 2010 were studied retrospectively. Needles of 22, 25 and 19 gauge were used. The associations between the EUS‐FNA results and factors such as mass location, mass size, needle size, number of needle passes, combined histologic‐cytologic analysis and final diagnosis were analyzed. Results: A total of 170 EUS‐FNA procedures were performed in 158 patients with upper gastrointestinal submucosal or extraluminal solid lesions. The overall accuracy of EUS‐FNA was 86.5% (147/170). The diagnostic accuracy with three or more needle passes was higher than with less than 3.0 needle passes (90.0%, 108/120 vs 78.0%, 39/50; P < 0.05). Mass location, mass size, and final diagnosis were not associated with EUS‐FNA accuracy. Combined cytologic‐histologic analysis had significantly higher diagnostic accuracy than either cytologic or histologic analysis alone (P < 0.001). In a subgroup of 90 patients, both 22 and 25 gauge needles were used for EUS‐FNA. The overall diagnostic accuracy was similar for 25 gauge needles and 22 gauge needles (80.0% vs 78.9% P = 1.000) in this subgroup. Conclusion: Overall, 25 and 22 gauge needles have a similar diagnostic accuracy. Our results suggest that 3.0 or more needle passes and combined cytologic‐histologic analysis enhance the diagnostic accuracy of EUS‐FNA.     

Role of endoscopy in the diagnosis of autoimmune pancreatitis and immunoglobulin G4‐related sclerosing cholangitis

Autoimmune pancreatitis (AIP) must be differentiated from pancreatic carcinoma, and immunoglobulin (Ig)G4‐related sclerosing cholangitis (SC) from cholangiocarcinoma and primary sclerosing cholangitis (PSC). Pancreatographic findings such as a long narrowing of the main pancreatic duct, lack of upstream dilatation, skipped narrowed lesions, and side branches arising from the narrowed portion suggest AIP rather than pancreatic carcinoma. Cholangiographic findings for PSC, including band‐like stricture, beaded or pruned‐tree appearance, or diverticulum‐like outpouching are rarely observed in IgG4‐SC patients, whereas dilatation after a long stricture of the bile duct is common in IgG4‐SC. Transpapillary biopsy for bile duct stricture is useful to rule out cholangiocarcinoma and to support the diagnosis of IgG4‐SC with IgG4‐immunostaining. IgG4‐immunostaining of biopsy specimens from the major papilla advances a diagnosis of AIP. Contrast‐enhanced endoscopic ultrasonography (EUS) and EUS elastography have the potential to predict the histological nature of the lesions. Intraductal ultrasonographic finding of wall thickening in the non‐stenotic bile duct on cholangiography is useful for distinguishing IgG4‐SC from cholangiocarcinoma. Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is widely used to exclude pancreatic carcinoma. To obtain adequate tissue samples for the histological diagnosis of AIP, EUS‐Tru‐cut biopsy or EUS‐FNA using a 19‐gauge needle is recommended, but EUS‐FNA with a 22‐gauge needle can also provide sufficient histological samples with careful sample processing after collection and rapid motion of the FNA needles within the pancreas. Validation of endoscopic imaging criteria and new techniques or devices to increase the diagnostic yield of endoscopic tissue sampling should be developed.     

PANCREATIC TUBERCULOSIS AND ITS DIAGNOSIS BY ENDOSCOPIC ULTRASONOGRAPHY: REPORT OF TWO CASES AND REVIEW OF THE LITERATURE

Mass lesions in the head of the pancreas are generally malignant and it is difficult to diagnose benign lesions preoperatively. We describe two patients with pancreatic tuberculosis, who presented with abdominal pain, jaundice and a pancreatic head mass, mimicking cancer. The correct diagnosis could be made by endoscopic ultrasonography (EUS) and EUS‐guided fine‐needle aspiration (FNA) cytology in both patients, precluding the need for surgery. Both patients responded well to anti‐tuberculosis treatment. We conclude that EUS with guided FNA is a useful modality to diagnose pancreatic tuberculosis.     

SUCCESSFUL ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION OF THE PELVIC LESION THROUGH THE SIGMOID COLON

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is a useful modality when the target is a lymph node located in the mediastinum, perigastric area or perirectum. Although it is difficult to carry out EUS‐FNA of the colon using an oblique view linear scope, we report two cases of successful EUS‐FNA of the lesions via the proximal sigmoid colon using a recently available new convex type EUS scope. Case 1 was a 77‐year‐old Japanese woman noted to have multiple lymph node swelling in the para‐aortic area and in the pelvis. Case 2 was a 60‐year‐old Japanese woman noted to have a large mass in the left lower abdomen. In case 1, oral EUS showed no lymph node swelling. In both cases, EUS with forward‐viewing radial echoendoscope was carried out via the anus, and multiple lymph‐node swelling or a large mass was observed near the proximal sigmoid colon. In the EUS‐FNA for these cases, we used a new convex‐type EUS scope that has an oblique view, but with a wide‐angled optical device giving a view similar to a forward one. EUS‐FNA was successfully carried out on the lesions. The pathological specimen revealed diffuse large B‐cell lymphoma in case 1 and gastrointestinal stromal tumor (GIST) in case 2.     

ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY FOR THE DIAGNOSIS OF GASTROINTESTINAL SUBMUCOSAL TUMORS

Gastrointestinal submucosal tumors (SMT) detected by barium meal study or endoscopy include various kinds of diseases and various degrees of malignancy. Endoscopic ultrasonography (EUS) can provide useful information about the differentiation of intra‐ and extra‐wall lesions, location and originating layer, presumption of their histological nature, measurement of the actual size of the lesion, and the possibility of differentiating between a benign and a malignant lesion. However, EUS alone does not reveal the complete pathology. EUS fine‐needle aspiration biopsy (EUS‐FNAB) has been reported to be a useful tissue sampling method for pancreatic mass lesions, lymph nodes swelling, posterior mediastinal masses and also gastrointestinal submucosal tumors. The EUS‐FNAB procedure is effective not only for the differential diagnosis of benignancy and malignancy, but also for the specific histopathological nature of gastrointestinal SMT using immunohistochemical staining. When used with MIB‐1 (Ki‐67) staining, and gene analysis in case of gastrointestinal stromal tumor, EUS‐FNAB may indicate its prognosis and influence decisions regarding therapeutic strategy. Thus, EUS‐FNAB is an indispensable procedure in the diagnosis of SMT.     

Endoscopic ultrasound‐guided fine‐needle aspiration of solid lesions on clopidogrel may not be a high‐risk procedure for bleeding: A case series

The major gastrointestinal endoscopy society guidelines list endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) as a high‐risk procedure for bleeding. However, there are no studies evaluating the risk of bleeding for EUS‐FNA of solid organs while patients continue to take clopidogrel. The aim of the present case series was to evaluate the rate of bleeding in a cohort of patients who underwent EUS‐FNA for solid lesions while on clopidogrel. Bleeding was measured at the time of the procedure by bleeding seen on EUS, endoscopic visualization of blood, or drop in hemoglobin after the procedure. From 2013 to 2015, 10 patients were identified for this case series. Lesions that underwent EUS‐FNA included gastric and rectal subepithelial lesions, pancreas masses, and liver masses. No immediate or delayed bleeding was observed in any of the patients. EUS‐FNA of solid lesions on clopidogrel may not be a high‐risk procedure for bleeding. Larger studies are needed to confirm this finding.     

Submucosal tumors: Comprehensive guide for the diagnosis and therapy of gastrointestinal submucosal tumors

Small submucosal tumors (SMT) without symptoms are frequently found by endoscopic and radiological examinations. To find proper diagnostic measures and therapeutic indications for histologically undiagnosed SMT, we reviewed published articles in PubMed between 1990 and March 2013 using the key words ‘submucosal tumor’ and the name of a specific disease. SMT is observed in a wide range of gastrointestinal (GI) diseases and conditions, including compression by extra‐GI organs and lesions, congenital tumors, inflammation, and benign as well as malignant neoplastic lesions. In the diagnosis of diseases and decision‐making for therapy, endoscopic ultrasonography (EUS) and endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) may play a key role. Symptomatic SMT and SMT histologically diagnosed as malignant or potentially malignant tumors such as gastrointestinal stromal tumor (GIST) should be treated by surgery. SMT >5 cm, SMT increasing in size and those with‘high‐risk features’ including irregular border, heterogeneous internal echo such as anechoic area, and heterogeneous enhancement by contrast media may also be removed by surgery. Laparoscopic approach is feasible for gastric GIST <5 cm and this is considered less invasive than the open approach. Emerging techniques using flexible endoscopes appear less invasive, but require further evidence and are still under clinical study. Correct diagnosis of SMT is challenging; however, EUS and EUS‐FNA are useful in the histological diagnosis and clinical decision‐making. In the future, minimally invasive approaches may be a mainstream of surgical treatment for small SMT.     

A prospective multicenter evaluation of a new side‐port endoscopic ultrasound‐fine‐needle aspiration in solid upper gastrointestinal lesions

Background and Study Aims: Diagnostic yield of endoscopic ultrasound (EUS)‐fine‐needle aspiration (FNA) varies depending on the equipment used and the site targeted. Multiple needle passes are usually required to obtain a diagnosis. A new needle incorporating a side‐port carries a theoretical advantage regarding acquisition of cytological material. The aim of the study was to demonstrate the safety and efficacy of the Olympus side‐port needle in solid upper gastrointestinal indications. Patients and Methods: A prospective multicenter evaluation of patients referred for EUS‐FNA for solid lesions was performed across six tertiary gastroenterology referral centers in four capital cities in Australia. The main outcome measures include cytological diagnosis, number of needle passes required for diagnosis and complication rates. Results: Thirty patients (17 men; 13 women) with a mean age of 67.5 years were studied. Indications included pancreatic or biliary mass in 24 patients, retroperitoneal or periduodenal mass in 2, enlarged lymph node in 2, a gastric submucosal tumor in 1 and a subcarinal mass in 1. The mean size of the lesions was 3.47 cm (range, 0.5–8 cm). All but one case had a diagnosis made (96.7%). The mean number of passes required to reach a diagnosis was 1.7. In neoplastic lesions the diagnosis was made with a mean of 1.6 passes. No complications were encountered. Conclusions: The new EUS‐FNA needle with side port appears effective and safe in solid upper gastrointestinal EUS‐FNA indications.     

EUS GUIDED FNA FOR MEDIASTINAL TUMORS (LUNG CANCER AND LYMPH NODES)

Trans‐esophageal endoscopic ultrasound‐guided fine needle aspiration biopsy (EUS‐FNA) has proven to be a safe and minimally invasive tissue‐sampling method which can be used to obtain a cytological diagnosis from mediastinal lesions. The aims of EUS‐FNA in the mediastinum are either to diagnose a lesion of unknown origin, to stage mediastinal lymph nodes in lung cancer patients or to diagnose other diseases involving lymph nodes of the mediastinum. In patients with non‐small cell lung cancer (NSCLC), surgery may be regarded as futile in up to 45% of patients operated, apparently because the stage of the disease is more advanced than expected preoperatively. This, combined with a stage‐dependent multimodality treatment, underlines the importance of exact staging of the disease. Conventional imaging and tissue sampling methods all have variable sensitivities. Twenty‐two studies concerning EUS‐FNA and mediastinal staging of lung cancer have been published with a total number of 1245 patients. The reported sensitivity for mediastinal malignancy range from 0.61–1.00 (median 0.90), and with specificities of 0.71–1.00 (median 1.00). The majority of the studies are retrospective and present the results of EUS‐FNA performed in lung cancer patients selected by computer tomography (CT). Recent data suggests that EUS‐FNA in addition can diagnose advanced mediastinal disease in 22–42% of NSCLC patients with normal sized lymph nodes (< 1 cm) on chest CT. EUS‐FNA may also be used as a re‐staging procedure after induction chemotherapy and it seems that EUS‐FNA is more accurate for mediastinal staging of NSCLC compared to positron emission tomography (PET). However, further studies are necessary before final conclusions can be made. At present, mediastinoscopy is still considered complementary to EUS‐FNA because EUS‐FNA cannot visualize structures anterior to the air‐filled trachea and main bronchi. Endoscopic trans‐bronchial real‐time ultrasound guided biopsy (EBUS‐TBNA) performed via the trachea and main bronchi seems to be an obvious solution. Preliminary experience with a prototype EBUS‐TBNA bronchoscope (Olympus, XBF‐UC40P, Tokyo, Japan) in 214 patients has shown promising results. Hopefully the combination of EUS‐FNA and EBUS‐TBNA will be able to replace more invasive and risky staging methods and improve the N‐staging accuracy of the mediastinum and lung hilar regions in the near future.     

Endoscopic ultrasound-guided fine-needle aspiration of lesions near the aortoiliac bifurcation via an upper gastrointestinal approach

Background and Aims: Endoscopic ultrasound (EUS)‐guided fine‐needle aspiration (FNA) is widely used to investigate posterior mediastinal and upper abdominal lesions. Previously, we noticed that the aortoiliac bifurcation can be visualized by transduodenal EUS scanning, and the surrounding area might be a potential target for EUS‐guided FNA. This study aimed to determine the feasibility of using EUS‐guided FNA to study lesions near the aortoiliac bifurcation via the upper gastrointestinal approach. Methods: This study was a prospective pilot study of consecutive patients with a lesion of unknown origin near the aortoiliac bifurcation. Results: EUS‐guided FNA was used in six patients. The aortoiliac bifurcation was visible from the inferior duodenal angle in all patients; however, the lesions could be visualized in only five patients (3 via the transduodenal approach, and 2 via the transgastric approach). In one patient with a lesion on the left side, the lesion could not be visualized by either the transgastric or transduodenal approach. In the other five patients, EUS‐guided FNA was successful, and FNA specimens were adequate for histopathological assessment. The diagnoses were lymphoma (n = 3), plasmacytoma (n = 1), and neurinoma (n = 1). All lymphoma cases were subclassified as diffuse large B‐cell lymphoma (n = 2) or grade 2 follicular lymphoma (n = 1). No complications were observed. Conclusions: The aortoiliac bifurcation was visible in all patients by transduodenal EUS scanning. FNA of the legions near the aortoiliac bifurcation was possible in five of six patients by using either the transgastric or transduodenal approach.     

Role of endoscopic ultrasonography in pancreatic cystic neoplasms: Where do we stand and where will we go?

We increasingly encounter pancreatic cystic neoplasms (PCN) in clinical practice and the differential diagnoses vary widely from benign to malignant. There is no ‘one and only’ diagnostic procedure for PCN. Multiple modalities including computed tomography, magnetic resonance imaging, endoscopic retrograde cholangiopancreatography and endoscopic ultrasound (EUS) are widely used, but EUS has the advantage of anatomical proximity to the pancreas and upper gastrointestinal tract. In addition, EUS‐guided fine‐needle aspiration (EUS‐FNA) provides both cytological evaluation and cyst fluid analysis. Although the role of EUS‐FNA for PCN is established, the sensitivity of cytology is low and cyst fluid analysis is only useful for differentiation between mucinous and non‐mucinous cysts. Recently, novel through‐the‐needle imaging under EUS‐FNA, such as confocal laserendomicroscopy, is expected to attribute to a better diagnostic yield. Moreover, feasibility of cyst ablation has been reported and the role of EUS has expanded from diagnosis to treatment. However, clinical impact of cyst ablation in terms of safety, efficacy and cost‐effectiveness should be validated further. In summary, EUS and EUS‐guided intervention does and will play a central role in the management of PCN from surveillance to treatment, but many clinical questions remain unanswered, which warrants well‐designed prospective clinical trials.     

Prospective evaluation of the optimal number of 25‐gauge needle passes for endoscopic ultrasound‐guided fine‐needle aspiration biopsy of solid pancreatic lesions in the absence of an onsite cytopathologist

Introduction: A prior study with 22‐gauge needles recommended more than seven needle passes for endoscopic ultrasound‐guided fine‐needle aspiration biopsy (EUS‐FNA) of solid pancreatic lesions (SPL) without onsite cytopathology for optimal acquisition of cytopathological diagnosis. The feasibility of this recommendation should be re‐evaluated considering the later development and popularity of 25‐gauge EUS‐FNA needles. We aimed to determine the optimal number of needle passes for cytopathological specimen acquisition with 25‐gauge needles for EUS‐FNA of SPL. Methods: A preliminary prospective study of 22 patients with an onsite cytopathology technician showed a sensitivity of 93.3% and a specificity of 100% with four needle passes that was not statistically different from five needle passes. Based on our preliminary study, we fixed the number of needle passes to four (Group A). As a control group, we carried out sampling in consecutive patients using 25‐gauge needles with an onsite cytopathologist (Group B). Sampling rate, diagnostic value and complications were evaluated. Results: We enrolled 20 patients in each group. Sampling rate was higher in Group B (20/20, 100%) than in Group A (19/20, 95%), but there was no statistical difference between them (P‐value = 0.31). In Group A, sensitivity, specificity and accuracy were 100% among 19. In Group B, sensitivity was 94.1%, specificity 100%, accuracy 95%. There were also no statistical differences between the groups. No complications were seen. Conclusion: Our study suggests that four needle passes using a 25‐gauge needle may be sufficient for EUS‐FNA of SPL where onsite cytology is not available.     

Endoscopic ultrasonography‐guided pancreatic duct access: Techniques and literature review of pancreatography,transmural drainage and rendezvous techniques

Endoscopic ultrasonography‐guided (EUS)‐guided pancreatic interventions have gained increasing attention. Here we review EUS‐guided pancreatic duct (PD) access techniques and outcomes. EUS‐guided PD intervention is divided into two types, antegrade and rendezvous techniques, following EUS‐guided pancreatography. In the antegrade technique, pancreaticoenterostomy is carried out by stent placement between the PD and the stomach, duodenum, or jejunum. Transenteric antegrade PD stenting is conducted by stent placement, advancing anteriorly into the PD through the pancreatic tract. The rendezvous technique is carried out by using a guidewire through the papilla or anastomotic site for retrograde stent insertion. In terms of EUS‐guided PD stenting, 11 case reports totaling 75 patients (35 normal anatomy, 40 altered anatomy) have been published. The technical success rate was greater than 70%. Early adverse events, including severe hematoma and severe pancreatitis,occurred in seven (63.6%) of 11 reports. Regarding the rendezvous technique, 12 case reports totaling 52 patients (22 normal anatomy, 30 altered anatomy) have been published. The technical success rate ranged from 25% to 100%. It was 48% in one report that involved more than 20 cases. Once stents were placed, all patients became free of symptoms. Early mild adverse events occurred in four (36.4%) of 11 reports. In conclusion, although it can be risky because of possible serious or even fatal adverse events, including pancreatic juice leakage, perforation and severe acute pancreatitis, EUS‐PD access seems to be promising for treating symptomatic pancreatic diseases caused by PD stricture and pancreaticoenterostomy stricture.     

ENDOSCOPIC ULTRASOUND‐GUIDED CHOLEDOCHODUODENOSTOMY

Endoscopic biliary drainage (EBD) may be unsuccessful in some patients, because of failed biliary cannulation or tumor infiltration, limiting endoscopic access to major papilla. The alternative method of percutaneous transhepatic biliary drainage carries a risk of complications, such as bleeding, portal vein thrombus, portal vein occlusion and intra‐ or extra‐abdominal bile leakage. Recently, endoscopic ultrasonography (EUS)‐guided biliary stent placement has been described in patients with malignant biliary obstruction. Technically, EUS‐guided biliary drainage is possible via transgastric or transduodenal routes or through the small intestine using a direct access or rendezvous technique. We describe herein a technique for direct stent insertion from the duodenal bulb for the management of patients with jaundice caused by malignant obstruction of the lower extrahepatic bile duct. We think transduodenal direct access is the best treatment in patients with jaundice caused by inoperable malignant obstruction of the lower extrahepatic bile duct when EBD fails.     

Endoscopic ultrasound in clinical practice

Endoscopic ultrasonography (EUS) is an accurate technique for the diagnosis and staging of benign and malignant lesions in the gastrointestinal tract and the mediastinum. EUS overcomes the limitations of other imaging diagnostic methods and gives the possibility to obtain tissue for histologic diagnosis (EUS guided FNA). The most useful indications of EUS are differentiation of submucosal tumors, staging for neoplasia, examination of the pancreato-biliary system and therapeutics. EUS can distinguish extrinsic compressions from intramural lesions and defines their nature (solid, cystic or vascular) and origin. EUS is useful for local staging of esophageal, gastric, duodenal, and rectal cancer using the TNM (tumor, node, metastases) system, as well as for diagnosing and staging of pancreatic lesions. The addition of EUS-guided FNA has improved the ability to detect malignant lymph node invasion. EUS is also highly sensitive for the diagnosis of choledocholithiasis, avoiding unnecessary danger of diagnostic ERCP. New therapeutic indications of EUS include drainage of pancreatic pseudocysts and abscesses and celiac plexus block and neurolysis. EUS has become an indispensable diagnostic method in gastroenterological everyday practice and should be part of most endoscopy units.     

Clinical practice guidelines for safe performance of endoscopic ultrasound/ultrasonography‐guided biliary drainage: 2018

Endoscopic ultrasound/ultrasonography‐guided biliary drainage (EUS‐BD) is a relatively new modality for biliary drainage after failed or difficult transpapillary biliary cannulation. Despite its clinical utility, EUS‐BD can be complicated by severe adverse events such as bleeding, perforation, and peritonitis. The aim of this paper is to provide practice guidelines for safe performance of EUS‐BD as well as safe introduction of the procedure to non‐expert centers. The guidelines comprised patient–intervention–comparison–outcome‐formatted clinical questions (CQs) and questions (Qs), which are background statements to facilitate understanding of the CQs. A literature search was performed using the PubMed and Cochrane Library databases. Statement, evidence level, and strength of recommendation were created according to the GRADE system. Four committees were organized: guideline creation, expert panelist, evaluation, and external evaluation committees. We developed 13 CQs (methods, device selection, supportive treatment, management of adverse events, education and ethics) and six Qs (definition, indication, outcomes and adverse events) with statements, evidence levels, and strengths of recommendation. The guidelines explain the technical aspects, management of adverse events, and ethics of EUS‐BD and its introduction to non‐expert institutions.     

Diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration for suspected pancreatic malignancy in relation to the size of lesions

Background and Aim: Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) is an accurate method for cytological confirmation of pancreatic malignancy, but it has been unknown whether its diagnostic accuracy for pancreatic lesions was affected by their size, location, or size of needles. Our aim was to investigate the accuracy of EUS‐FNA for suspected pancreatic malignancy in relation to these factors, especially to the size of lesions. Methods: In a tertiary referral center, EUS‐FNAs for 120 suspected pancreatic malignancies in 115 patients based on other imaging studies were evaluated retrospectively. Results: Overall accuracy of EUS‐FNA was 96% (115/120), with sensitivity of 95% (76/80), specificity of 98% (39/40), positive predictive value of 99% (76/77), and negative predictive value of 91% (39/43). Accuracies for lesions less than 10 mm, 11–20 mm, 21–30 mm, and more than 31 mm were 96%, 95%, 96%, and 100%, respectively; those for lesions in the head, the body, and the tail of the pancreas were 96%, 95%, and 95%, respectively. Accuracies for 22‐gauge and 25‐gauge needle were 93% and 98%, respectively. Conclusion: EUS‐FNA was accurate in the evaluation of suspected pancreatic malignancy regardless of its size, location, or size of needles. It was useful also in the confirmation of small pancreatic malignancies less than 10 mm.     

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB): past, present, and future

Endoscopic ultrasound (EUS) is a combination of endoscopy and intraluminal ultrasonography. EUS also enables ultrasonographic images of high resolution to be obtained. However, whether a lesion is malignant or benign cannot be diagnosed solely from the findings of EUS. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) was developed to enhance the diagnostic capabilities of EUS by providing additional pathological findings. Though more than 10 years have passed since EUS-FNAB was first used for pancreatic disease, EUS FNAB has not been widely accepted in Japan. This may be due to the technical difficulties, relatively low sensitivity for the detection of malignancies, and Japanese gastroenterologists' and surgeons' inherent conservative way of thinking. We describe here a short history of EUS-FNAB, with details of technical tips, current indications and contraindications, diagnostic accuracy, and complications. The clinical utility of EUS-FNAB has been gradually understood and EUS-FNAB procedures have been increasing in number in Japan. So in the near future, EUS followed by EUS-FNAB will be routinely performed in the same manner as gastrointestinal endoscopy, followed by biopsy under direct vision. Also, therapeutic EUS procedures, such as EUS-guided celiac plexus neurolysis, pancreatic tumor ablation, drainage of pancreatic pseudocysts, and the development of an anastomosis may become feasible as less invasive and safer techniques than those used at present.     

Diagnosis of pancreatic cystic neoplasms: a report of the cooperative pancreatic cyst study

BACKGROUND & AIMS: Cysts of the pancreas display a wide spectrum of histology, including inflammatory (pseudocysts), benign (serous), premalignant (mucinous), and malignant (mucinous) lesions. Endoscopic ultrasonography (EUS) may offer a diagnostic tool through the combination of imaging and guided, fine-needle aspiration (FNA). The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cystic lesions. METHODS: The results of EUS imaging, cyst fluid cytology, and cyst fluid tumor markers (CEA, CA 72-4, CA 125, CA 19-9, and CA 15-3) were prospectively collected and compared in a multicenter study using histology as the final diagnostic standard. RESULTS: Three hundred forty-one (341) patients underwent EUS and FNA of a pancreatic cystic lesion; 112 of these patients underwent surgical resection, providing a histologic diagnosis of the cystic lesion (68 mucinous, 7 serous, 27 inflammatory, 5 endocrine, and 5 other). Receiver operator curve analysis of the tumor markers demonstrated that cyst fluid CEA (optimal cutoff of 192 ng/mL) demonstrated the greatest area under the curve (0.79) for differentiating mucinous vs. nonmucinous cystic lesions. The accuracy of CEA (88 of 111, 79%) was significantly greater than the accuracy of EUS morphology (57 of 112, 51%) or cytology (64 of 109, 59%) (P < 0.05). There was no combination of tests that provided greater accuracy than CEA alone (P < 0.0001). CONCLUSIONS: Of tested markers, cyst fluid CEA is the most accurate test available for the diagnosis of mucinous cystic lesions of the pancreas.     

The Capability of Three Dimensional Display during Endoscopic Ultrasonography

Abstract: Endoscopic ultrasonography (EUS) has been found to be useful in determining the depth of invasion of gastric cancer, the diagnosis of submucosal tumors and extramural compressions. A problem with this procedure is that it is difficult to determine stereoscopically the relative position of the lesion as a whole, even though EUS may be an excellent diagnostic tool for determining tomographies. In this paper, we made three-dimensional displays of EUS images using a personal computer to facilitate understanding of the relative anatomical positions of the lesions. During EUS examination, the distance from the incisors was acccurately measured, and the EUS image was recorded on U-matic tape. To measure the distance from the incisors, we devised a new instrument for measuring the endoscopic insertion length. The recorded tape was edited for input into the computer. The soft-ware for the three-dimensional display program was made by Photoron. Inc. A patient with esophageal cancer, a patient with a common bile duct stone and a patient with pancreatic cancer are presented as examples for definition of the relationship with the surrounding organs. A patient with a gastric ulcer is used as an example to clarify the pathological structure of the lesions. Using our method on these patients, it was easy to obtain a stereograph and to obtain complete images of the lesions. EUS was available for three -dimensional displays of the lesions in the gastrointestinal tract and in the surrounding area, and this has clinical significance.