Current roles of endoscopy in the management of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by intraductal papillary proliferation of mucin‐producing epithelial cells that exhibit various degrees of dysplasia. IPMN is classified into four histological subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) according to its histomorphological and immunohistochemical characteristics. Endoscopic retrograde cholangiopancreatography plays a crucial role in the evaluation of these features of IPMN. Endoscopic ultrasonography (EUS) has proven to be more sensitive than computed tomography or magnetic resonance imaging for early detection of malignancy. The present review addresses the current roles of endoscopy and related techniques in the management of IPMN. The particular focus is on diagnosing IPMN and malignancy within IPMN, detecting pancreatic cancer concomitant with IPMN, differentiating the epithelial subtypes of IPMN, determining the optimal strategy for the management of branch duct IPMN, and discussing innovative endoscopic technology related to IPMN. The disadvantages of endoscopic examinations of IPMN and different attitudes toward EUS‐guided fine‐needle aspiration for IPMN between Japan (negative) and other countries (active) are also discussed.     

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.     

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.     

胰腺假性囊肿内镜超声图像的特征

目的：研究胰腺假性囊肿内镜超声图像的特征，探讨内镜超声在胰腺假性囊肿诊断中的价值。方法：对35例胰腺假性囊肿患者进行超声内镜检查。结果：在35例胰腺假性囊肿中，单发3l例，多发4例，共有囊肿41个；位于胰头13个，胰体3个，胰尾19个，胰体尾6个。囊壁光滑29例，毛糙6例；囊液透声良好19例，有絮状回声16例，囊内有分隔l例，囊壁有钙化l例，伴有胰管扩张7例；胰腺实质回声不均匀21例，胰实质钙化4例，胰腺萎缩2例，胰腺癌2例，胰腺未见异常6例。5例在胃肠道有压迹，其中1例压迫十二指肠降段致梗阻；胃底静脉曲张4例，2例引起消化道出血。结论：内镜超声可以清晰显示囊肿的大小、部位、形态以及与胰腺的关系，且能进行EUS引导下的穿刺检查，对假性囊肿的诊断和鉴别诊断均有重要意义。     

Current status on the diagnosis and management of pancreatic cysts in the Asia-Pacific region: role of endoscopic ultrasound

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) play increasingly prominent roles in the diagnosis and management of pancreatic cysts. The Asian Consortium of Endoscopic Ultrasound was recently formed to conduct collaborative research in this area. This is a review of literature on true pancreatic cysts. Due to the lack of systematic studies, there are no robust data on the true incidence of pancreatic cystic lesions in Asia and any change in over the recent decades. Certain EUS morphological features have been used to predict particular types of pancreatic cysts. Pancreatic cyst fluid viscosity, cytology, pancreatic enzymes, and tumor markers, in particular carcinoembryonic antigen, can aid in the diagnosis of pancreatic cysts. Hemorrhage and infection are the most common complications of EUS-FNA of pancreatic cysts. Pancreatic cysts can either be observed or resected depending on the benign or malignant nature, or malignant potential of the lesions. Guidelines from an international consensus did not require positive cytological findings to be present in their recommendation for resection, which included all mucinous cystic neoplasms, all main-duct intraductal papillary mucinous neoplasms (IPMN), all mixed IPMN, symptomatic side-branch IPMN, and side-branch IPMN larger than 3 cm. In patients with poor surgical risks, EUS-guided cyst ablation of mucinous pancreatic cysts is an alternative. As long-term prospective data on pancreatic cysts are still not available in Asia, management strategies are largely based on risk stratification by surgical risk and malignant potential. Gene expression profiling of pancreatic cyst fluid and confocal laser endomicroscopic examination of pancreatic cysts are novel techniques currently being studied.     

Small invasive ductal carcinoma of the pancreas distinct from branch duct intraductal papillary mucinous neoplasm

Endoscopic ultrasonography (EUS) is a highly sensitive diagnostic method for the detection of small pancreatic carcinomas.Recently, there have been some reports describing the utility of contrast-enhanced harmonic EUS (CEH-EUS) which uses sonographic contrast agent for differentiation of a pancreatic mass.This report describes a case of small adenocarcinoma of the pancreas distinct from branch duct intraductal papillary mucinous neoplasm (IPMN) in which investigation by EUS took place every 6 mo and diagnosis was made accurately by additional CEH-EUS during the followup of the branch duct IPMN.A 68-year-old female was admitted to our hospital because of a branch duct IPMN in the pancreatic body.She had been followedup by EUS every 6 mo.However, after 2 years EUS demonstrated a low echoic area distinct from the branch duct IPMN which was vaguely discernible by EUS, and accurate sizing and differential diagnosis were considered difficult on the EUS imaging.CHEUS with Sonazoid revealed a hypovascular tumor and we suspected small pancreatic carcinoma.The histopathological diagnosis was adenocarcinoma (10 mm) in the pancreatic tail, distinct from the branch duct IPMN of the pancreatic body.EUS and CEH-EUS may play an important role in the correct diagnosis of small pancreatic tumors, including synchronous and metachronous occurrence of IPMN and ductal adenocarcinoma of the pancreas.     

Localized type 1 autoimmune pancreatitis superimposed upon preexisting intraductal papillary mucinous neoplasms

A 70-year-old woman was found to have 2 cystic lesions in the head of the pancreas on abdominal ultrasonography during a routine medical examination.Endoscopic ultrasonography(EUS)and magnetic resonance cholangiopancreatography showed multilocular cysts in the head of the pancreas without dilation of the main pancreatic duct.The patient was followed-up semiannually with imaging studies for suspected branch duct-type intraductal papillary mucinous neoplasm(IPMN).At 3 years after initial presentation,hypoechoic lesions were observed around each pancreatic cyst by EUS.Diffusion-weighted imaging showed high-intensity regions corresponding to these lesions.Therefore,a diagnosis of invasive carcinoma derived from IPMN could not be excluded,and subtotal stomach-preserving pancreaticoduodenectomy was performed.The macroscopic examination of the surgical specimen showed whitish solid masses in the head of the pancreas,with multilocular cysts within each mass.Microscopically,each solid mass consisted of inflammatory cells such as lymphocytes and plasma cells.Furthermore,immunochemical staining revealed immunoglobulin G4-positive cells,and many obliterating phlebitides were observed.The cysts consisted of mucus-producing epithelial cells and showed a papillary growth pattern.Based on these findings,we diagnosed multiple localized type 1 autoimmune pancreatitis occurring only in the vicinity of the branch ducttype IPMN.     

EUS FNA in intraductal papillary mucinous tumors of the pancreas

BACKGROUND/AIMS: There is little information concerning the potential role of fine-needle aspiration guided by endoscopic ultrasonography in the pathologic diagnosis of intraductal papillary mucinous tumors of the pancreas. METHODOLOGY: Patients with an intraductal papillary mucinous tumor of the pancreas suggested by endoscopic ultrasonography underwent fine-needle aspiration guided by endoscopic ultrasonography in order to investigate the presence of mucin and/or cytologic changes consistent with this diagnosis. A group of 111 patients with other pancreatic lesions explored during the same period of time was used as a control group. RESULTS: Fine-needle aspiration guided by endoscopic ultrasonography was safely performed in 19 patients and supported the diagnosis in 17 of them. Nine out of the 17 patients with suspicion of intraductal papillary mucinous tumors of the pancreas went to surgery and this diagnosis was confirmed in the resected specimen in all of them. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EUS FNA in the diagnosis of IPMT were 82%, 100%, 100%, 92% and 94% respectively. CONCLUSIONS: Fine-needle aspiration guided by endoscopic ultrasonography is a good technique to support the diagnosis of intraductal papillary mucinous tumors of the pancreas and should be considered in this group of patients if pathologic confirmation is judged to be necessary.     

Clinicopathological features and medical management of intraductal papillary mucinous neoplasms

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) are a clinicopathological entity that is being diagnosed with increasing frequency. However, the best approach to medical management of IPMN needs to be clarified. The aim of the present study was to identify preoperative features that may be predictors of malignant IPMN, and to define the medical management of IPMN of the pancreas. METHODS: A total of 23 patients who underwent surgical resection for IPMN of the pancreas at Kochi Medical School between 1982 and 2004 were examined. Multivariate Cox regression analysis was used to identify factors independently associated with IPM carcinoma. RESULTS: Among the 23 patients, 12 had IPMN adenoma, three had borderline IPMN, four had IPMN with carcinoma in situ, and four had IPMN with invasive carcinoma. In multivariate analysis, elevated serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels were found to be preoperative predictors of malignant IPMN. These results suggest that the following IPMN of the pancreas should be resected: (i) IPMN of the pancreas situated in the main duct; (ii) IPMN located in the branch duct if the size of the cystic lesion is >30 mm and the mural nodules are >5 mm in height by endoscopic ultrasound (EUS); and (iii) the diameter of the main pancreatic duct is >10 mm by endoscopic retrograde pancreatography (ERP). Careful observation of patients with branch-type IPMN with small cysts and/or without mural nodules is recommended as a management strategy. CONCLUSION: The present study reinforces the need for immediate surgical resection of malignant IPMN and suggests indicators for IPMN that should assist physicians in making decisions on treatment options.     

Performance of endosonography-guided fine needle aspiration and biopsy in the diagnosis of pancreatic cystic lesions

OBJECTIVE: Preoperative diagnosis of cystic lesions of the pancreas remains difficult despite improvement in imaging modalities and cystic fluid analysis. The aim of our study was to assess the performance of endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (FNA) in the diagnosis of pancreatic cystic lesions. METHODS: Data from a series of 127 consecutive patients with pancreatic cystic lesions were prospectively studied. EUS and EUS-guided FNA were performed in all patients, and cystic material was used for cytological and histological analysis as well as for biochemical and tumor markers analysis. Performance of EUS diagnosis, biochemical and tumor markers, and FNA diagnosis were compared with the final histological diagnosis obtained at surgery or postmortem examination. Sixty-seven patients underwent surgery and therefore constituted our study group. RESULTS: EUS provided a tentative diagnosis in 113 cases (89%). Cytohistological FNA provided a diagnosis in 98 cases (77%). When the results of EUS and EUS-guided FNA were compared with the final diagnosis (67 cases), EUS correctly identified 49 cases (73%), whereas FNA correctly identified 65 cases (97%). Sensitivity, specificity, positive predictive value, and negative predictive value of EUS and EUS-guided FNA to indicate whether a lesion needed further surgery were 71% and 97%, 30% and 100%, 49% and 100%, and 40% and 95%, respectively. Carbohydrate antigen 19-9 > 50,000 U/ml had a 15% sensitivity and a 81% specificity to distinguish mucinous cysts from other cystic lesions, whereas it had a 86% sensitivity and a 85% specificity to distinguish cystadenocarcinoma from other cystic lesions. CONCLUSIONS: EUS-guided FNA is a valuable tool in the preoperative diagnostic assessment of pancreatic cystic lesions.     

Endoscopic approach to early diagnosis of pancreatic cancer

Since its development, endoscopic retrograde cholangiopancreatography (ERCP) has been playing a major role in the diagnosis of pancreatic diseases. The recent development of magnetic resonance cholangiopancreatography has accelerated the shift in the role of ERCP toward more therapy-oriented applications. In the diagnosis and treatment of curable pancreatic cancer, however, ERCP remains the mainstay of imaging modalities. ERCP is not simply a method with which to obtain x-ray images of the pancreatic duct. Collection of pure pancreatic juice, transpapillary biopsy/brush cytology of the pancreatic duct, intraductal ultrasonography, and peroral pancreatoscopy are all performed based on the ERCP technique. Endoscopic ultrasonography (EUS) has a high spatial resolution and provides tomographic images of the pancreas and its neighboring organs. EUS is now widely used in evaluation of the local extent of pancreatic cancer and the differential diagnosis of cystic lesions of the pancreas. EUS-guided fine needle aspiration biopsy/cytology is performed to obtain a histologic diagnosis before beginning chemotherapy. Although the number of pancreatic cancer patients who are candidates for surgery is limited at present, there is an increasing need for ERCP-based techniques in both the diagnosis and treatment of pancreatic neoplasms.     

Macrocystic Serous Cystadenoma of the Pancreas

Abstract: The case of a 61 -year-old man with macrocystic serous cystadenoma of the pancreas is reported. Abdominal ultrasonography and computerized tomography showed a multilocular cystic lesion in the body of the pancreas. The major cysts ranged in size from more than 2.0 cm up to 6.0 crn. Endoscopic ultrasonography (EUS) showed a few small cysts in addition to the large cysts. The preoperative diagnosis was either mucinous cystic tumor or congenital cyst of the pancreas and tumor enucleation was performed. Histological examination revealed serous cystadenoma of the pancreas with macrocysts. Detecting small cysts with EUS may be useful for distinguishing this unusual tumor from mucinous cystic tumors.     

CLINICAL SIGNIFICANCE OF INTRADUCTAL ULTRASONOGRAPHY FOR DIAGNOSIS OF INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM OF THE PANCREAS

Intraductal ultrasonography (IDUS) is useful for evaluating the horizontal spread along the main pancreatic duct in cases of intraductal papillary mucinous neoplasm (IPMN) of the pancreas, thus providing valuable information for the determination of the resection line at surgery. Differentiation between benign and malignant IPMN is also indispensable for management decisions. Measurement of the height of mural nodules by IDUS is expected to be useful for differential diagnosis of IPMN. Because IDUS cannot always demonstrate whole lesions, especially in branch duct IPMN, endoscopic ultrasonography plays a complementary role in such cases.     

COMPARISON OF THE HEIGHT OF PAPILLARY TUMOR IN INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM OF THE PANCREAS BETWEEN MEASURED PREOPERATIVE IMAGES AND RESECTED MATERIAL

The height of the mural nodules and papillary tumors in main pancreatic duct or dilated branch duct is the most important factor for diagnosis of intraductal papillary mucinous neoplasm (IPMN). In this study, the authors compared the height of the papillary lesions and mural nodules between the height of resected tissues and the height detected by the preoperative imaging tools (endoscopic ultrasonography [EUS] and intraductal ultrasonography [IDUS]) in 38 patients with IPMN. In 21 out of 23 cases of adenoma, and in cases with the non‐invasive cancer, the difference of the height of operative and preoperative analysis measured by EUS and IDUS was within 1–2 mm. EUS and IDUS are useful for diagnosis of degree of malignancy in IPMN.     

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.     

Endosonography in the diagnosis and management of pancreatic cysts

Rapid advances in radiologic technology and increased cross-sectional imaging have led to a sharp rise in incidental discoveries of pancreatic cystic lesions. These cystic lesions include non-neoplastic cysts with no risk of malignancy, neoplastic non-mucinous serous cystadenomas with little or no risk of malignancy, as well as neoplastic mucinous cysts and solid pseudopapillary neoplasms both with varying riskof malignancy. Accurate diagnosis is imperative as management is guided by symptoms and risk of malignancy. Endoscopic ultrasound(EUS) allows high resolution evaluation of cyst morphology and precise guidance for fine needle aspiration(FNA) of cyst fluid for cytological, chemical and molecular analysis. Initially, clinical evaluation and radiologic imaging, preferably with magnetic resonance imaging of the pancreas and magnetic resonance cholangiopancreatography, are performed. In asymptomatic patients where diagnosis is unclear and malignant risk is indeterminate, EUSFNA should be used to confirm the presence or absence of high-risk features, differentiate mucinous from non-mucinous lesions, and diagnose malignancy. After analyzing the cyst fluid for viscosity, cyst fluid carcinoembryonic antigen, amylase, and cyst wall cytology should be obtained. DNA analysis may add useful information in diagnosing mucinous cysts when the previous studies are indeterminate. New molecular biomarkers are being investigated to improve diagnostic capabilities and management decisions in these challenging cystic lesions. Current guidelines recommend surgical pancreatic resection as the standard of care for symptomatic cysts and those with high-risk features associated with malignancy. EUSguided cyst ablation is a promising minimally invasive, relatively low-risk alternative to both surgery and surveillance.     

Mode of progression of intraductal papillary-mucinous tumor of the pancreas: analysis of patients with follow-up by EUS

Background We investigated the mode of progression of intraductal papillary-mucinous neoplasm of the pancreas (IPMN) in patients who underwent follow-up in order to elucidate the characteristics of malignancy and to establish an effective treatment strategy.Methods Fifty-one patients with IPMN (branch-duct type, 47; main-duct type, 4) who had undergone follow-up study by endoscopic ultrasonography (EUS) were included (mean follow-up duration, 41.0 ± 32.3 months; average number of EUS examinations performed during follow-up, 4.4). Chronological changes in EUS findings and histological findings of resected specimens were evaluated.Results Of the patients with the branch-duct type, only 2% showed enlargement of the dilated branches. In the main-duct-type group, an increase in size of the main pancreatic duct (MPD) was observed in 75% of the patients. In 14 patients with papillary protrusions, an increase in size and lateral spread was observed in 71% and 43%, respectively. No patients developed invasive cancer. In 15 patients who had thick septum-like structures (TSS), the development of papillary protrusions and that of invasive cancer were observed in 53% and 13%, respectively. Twenty-nine patients who had thin septum-like structures showed no change. Two patients with dense multilocular large cysts and TSS developed invasive cancer without change in the cystic lesions. One patient developed carcinoma with multifocal stromal invasion.Conclusions Patients with branch-duct type IPMNs without papillary protrusions or TSS are not immediate candidates for surgery. Those who have small papillary protrusions have a benign course. It is recommended that patients with the large branch-duct type with TSS should undergo surgery. Attention should be paid to the entire pancreas when performing follow-up examinations in patients with branch-duct type IPMN, as invasive ductal adenocarcinoma can develop at a site in the pancreas different from that of the IPMN.     

Accuracy of preoperative workup in a prospective series of surgically resected cystic pancreatic lesions

Abstract Background. Magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS) are considered useful techniques in the evaluation of pancreatic cysts. Aim of this study was to prospectively compare the diagnostic value of these techniques. Methods. This study included consecutive patients who underwent MRI, EUS, and EUS-FNA for a pancreatic cyst that was eventually resected surgically. Observers scored for cyst characteristics, a distinction between mucinous and non-mucinous cysts and a suspicion of malignancy. The interobserver agreement between MRI and EUS was calculated. Results. A total of 32 patients were included. Sensitivity for diagnosing a mucinous cyst was 78% for EUS versus 91% for MRI. Sensitivity for detecting malignancy was 25% (1/4) and 50% (2/4) for EUS and MRI respectively. Sensitivity of EUS-FNA for diagnosing a mucinous cyst (positive cytology and/or CEA >192 ng/ml) was 61%. Sensitivity for detecting malignancy (positive cytology) was 1/4 (25%). Interobserver agreement between MRI and EUS for the features was poor to fair. Conclusion. MRI and EUS are comparable techniques for the morphological characterization of pancreatic cysts. Combined sensitivity of EUS and MRI was higher than the sensitivity of one of the techniques alone. For diagnosing a mucinous cyst, FNA findings showed a low sensitivity, but a high specificity.     

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.     

Factors Determining Diagnostic Yield of Endoscopic Ultrasound Guided Fine-Needle Aspiration for Pancreatic Cystic Lesions: A Multicentre Asian Study

Background and Aim

The purpose of this study was to determine (1) the diagnostic yield for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with pancreatic cystic lesions, (2) additional value of EUS-FNA over EUS alone in the diagnosis of pancreatic cysts, and (3) diagnostic sensitivity and specificity of EUS and EUS-FNA in the subset of patients where histopathology of surgical specimens were available.

Methods

All patients who underwent EUS examination for the evaluation of pancreatic cystic lesions in six Asian centres were included in the study.

Results

Of 298 patients with pancreatic cysts who underwent EUS, 132 (44.3 %) underwent FNA. In the entire cohort, pseudocysts and intraductal papillary mucinous neoplasm (IPMN) were the predominant cystic lesions. The cytologic yield of EUS-FNA was 47 %. On univariate analysis, factors associated with higher cytologic yield included vascular involvement on EUS, presence of solid cystic component, and increased number of needle passes during EUS-FNA. On multivariate analysis, presence of solid cystic components and increased number of needle passes during EUS-FNA were associated with higher diagnostic yield of EUS-FNA. For pancreatic cysts with a solid component, the diagnostic yield of EUS-FNA increased significantly from 44 % with one pass to 78 % with more than one pass (p = 0.016). In the absence of a solid component, the diagnostic yield was 29 % with one pass and was not significantly different from the diagnostic yield of 50 % with more than one pass, p = 0.081.

Conclusion

The cytologic yield of EUS-FNA was 47 %. When a solid component was present in the cyst, doing more than one pass during EUS-FNA increased its diagnostic yield.