Endoscopic ultrasonography of nonfunctioning pancreatic islet cell tumors with histologic correlation

BACKGROUND/AIMS: Preoperative differentiation of benign and malignant pancreatic nonfunctioning islet cell tumors remains problematic. The present study aimed to evaluate endoscopic ultrasonography (EUS) features of benign and malignant tumors with histologic correlation. METHODOLOGY: Ten patients with surgically resected nonfunctioning pancreatic islet cell tumors were retrospectively reviewed. RESULTS: EUS demonstrated a homogenous hypoechoic (n=2) or hyperechoic (n=1) mass in the 3 benign tumors. EUS showed a hypoechoic mass with an irregular central hyperechoic portion (n=4), a hyperechoic mass with an irregular central hypoechoic portion (n=1), a cystic mass with a large irregular internal hypoechoic portion (n=1), or a hypoechoic mass within the entire lumen of the main pancreatic duct (MPD) (n=1) in the 7 malignant tumors. Histologically, the irregular central portions of the malignant tumors corresponded to necrosis, hemorrhage, fibrosis with hyalinosis, cystic degeneration, and/or calcification. Complete obstruction of the main pancreatic duct on EUS was observed in the 2 malignant tumors. The echogenicity of the tumors was closely associated with arrangement of tumor cells and quantity of fibrous stroma. CONCLUSIONS: Heterogeneous internal structures and complete obstruction of the main pancreatic duct are considered as important EUS features that are suggestive of malignancy in nonfunctioning pancreatic islet cell tumors.     

Intraductal growth of a nonfunctioning endocrine tumor of the pancreas

Intraductal growth of nonfunctioning endocrine tumors of the pancreas may be very rare, and our survey of literature shows only two cases have been described. We report a case of a 43-year-old man with a nonfunctioning endocrine tumor of the pancreas that uniquely grew within the lumen of the main pancreatic duct (MPD) without ductal involvement and completely obstructed the MPD. Endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) were very helpful to delineate the intraductal growth of the tumor and to determine the resection line of the pancreas. A nonfunctioning pancreatic endocrine tumor is important to consider on differential diagnoses when complete obstruction of the MPD is demonstrated on ERCP. It is speculated that the tumor originated from precursor cells of the pancreatic duct or islet cells adjacent to the MPD and slowly proliferated within the lumen of the MPD.     

Endoscopic ultrasound characteristics of mucinous cystic neoplasms of the pancreas

OBJECTIVE: Mucinous cystic neoplasms of the pancreas have a more favorable prognosis than ductal adenocarcinoma. Management of a subgroup, intraductal papillary-mucinous neoplasms, is controversial. Endoscopic ultrasound (EUS) with fine-needle aspiration biopsy may emerge as the imaging modality of choice. There are few studies describing the EUS features of these tumors. METHODS: A total of 35 consecutive cases of cystic tumors of the pancreas with an established pathological diagnosis were analyzed for characteristic EUS features. RESULTS: Mucinous cystadenocarcinomas (n = 14) were more likely to be characterized by hypoechoic cystic/solid mass or complex cyst and were frequently associated with a dilated main pancreatic duct. Benign mucinous duct ectasia (n = 6) were characterized by a dilated main pancreatic duct in conjunction with hyperechoic thickening of the duct wall. The two cases of intraductal mucinous hyperplasia additionally showed a hypoechoic mass. Intraductal papillary carcinoma (n = 11) had features in common with mucinous cystadenocarcinoma but also had echogenic foci in the mass and intraductal hyperechoic lesions. The two cases of microcystic cystadenoma showed either a mixed hypoechoic solid/cystic mass or a complex cyst without the additional features seen in mucinous cystadenocarcinoma. CONCLUSIONS: EUS features seem to exist that may help to differentiate cystic neoplasms from adenocarcinoma of the pancreas and, thus, to establish the preoperative diagnosis of cystic tumors of the pancreas.     

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES: Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT. METHODS: A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens. RESULTS: In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%. CONCLUSIONS: Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.     

Nonfunctioning pancreatic neuroendocrine tumors presenting as pancreatitis: report of four cases

The presentation of pancreatic adenocarcinoma as acute or chronic pancreatitis has been well documented; however, there has been only one previous report of either functioning or nonfunctioning pancreatic neuroendocrine tumors associated with pancreatitis. At the Medical University of South Carolina in Charleston, from March 1982 through September 1987, we have managed four patients with nonfunctioning pancreatic islet cell tumors or carcinoids, which presented with attacks of pancreatitis. Three of the patients had recurrent bouts of upper abdominal and lower dorsal back pain with elevation of the serum amylase. One patient presented initially with acute upper abdominal pain and elevation of the serum amylase. Each patient had an endoscopic retrograde cholangeography pancreatography (ERCP) pattern involving the pancreatic duct which was characterized by diffuse dilatation proximal to the site of obstruction. One of the four had a tumor blush on splanchnic angiography. Each patient had CT evidence of a mass in the head of the pancreas; however, one of the four was found to have diffuse involvement of the entire gland at operation. Surgical therapy varied: (a) local excision of the ampullary area with re-anastomosis of the pancreatic duct to the duodenum and choledochoduodenostomy; (b) bypass with cholecystoduodenostomy and caudal pancreaticojejunostomy; (e) total pancreatectomy; or (d) bypass with a Roux-en-Y cholecystojejunostomy and gastrojejunostomy. The choice of the procedure was based on the patient's condition and operative findings.     

超声内镜对胰管扩张性疾病的诊断价值

目的 探讨内镜超声检查术(EUS)在胰管扩张病因及恶性疾病邻近脏器浸润的诊断价值。方法 分析129例EUS检查发现胰管扩张的病因，并与同期接受CT检查(n＝40)与ERCP检查(n＝42)的结果相比较。对其中72例胰腺癌引起的胰管扩张病例，分析EUS对邻近脏器浸润检出率，并与CT、ERCP结果相比较。结果 129例胰管扩张病例中，胰腺癌、壶腹癌、慢性胰腺炎为常见病因。EUS对病因检出率较CT及ERCP高。EUS对胰腺癌邻近血管侵犯及淋巴结转移检出率较CT及ERCP高。结论 EUS对胰管扩张的病因诊断较CT及ERCP有明显的优越性，并能全面评估肿瘤的可切除性，指导制定治疗方案。     

Islet cell tumors of the pancreas. The diagnostic value of endoscopic retrograde pancreatography

Eleven cases of pancreatic islet cell tumors were reviewed to compare diagnostic ability of endoscopic retrograde pancreatography (ERP) with other imaging modalities. ERP localized three out of five tumors studied and showed a suspicious finding in an additional patient. All these tumors were located in the pancreatic head. Thus, the diagnostic ability of ERP was superior in the head portion, where recognition of a tumor is often difficult at the operation, and a more complicated procedure is required for removal. Nonfunctioning islet cell tumors were localized by hypervascularity on angiogram, but retroperitoneal leiomyosarcoma remained to be excluded in one patient. ERP with an indwelling balloon catheter revealed the pancreatic origin of the tumors and precisely determined the line of pancreatic resection by vividly visualizing pancreatic duct obstruction and intact distal branches. We conclude that ERP is helpful to localize functioning islet cell tumors of the pancreas especially in the head portion and plays an important role for planning resection of nonfunctioning islet cell tumors.     

Endosonography-guided fine needle aspiration biopsy in the evaluation of pancreatic masses

OBJECTIVES: Diagnosis of pancreatic tumors can be problematic. This study aimed to determine the performance of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS FNA) in pancreatic malignancy when prior biopsies performed by CT guidance or ERCP were negative. METHODS: A total of 185 patients with known or suspected pancreatic masses were prospectively evaluated with EUS FNA. Before EUS FNA, all patients were evaluated with abdominal CT (61 with CT-guided biopsy) and 91 with ERCP (41 had brushings or biopsy). RESULTS: EUS had greater sensitivity than CT in detecting a mass (99% vs 57%, p < 0.0001). In 58 patients with negative CT-guided biopsies, EUS FNA had 90% sensitivity for malignancy, 50% specificity for benign disease and 84% accuracy. Similarly, in 36 patients with negative ERCP tissue sampling, results for EUS FNA were 94%, 67% and 92%, respectively. Complications were mild and infrequent (0.5%). CONCLUSION: EUS FNA of pancreatic masses safely and accurately diagnoses pancreatic malignancy when prior biopsy techniques have been unsuccessful.     

Islet cell tumors of the pancreas The diagnostic value of endoscopic retrograde pancreatography

Eleven cases of pancreatic islet cell tumors were reviewed to compare diagnostic ability of endoscopic retrograde pancreatography (ERP) with other imaging modalities. ERP localized three out of five tumors studied and showed a suspicious finding in an additional patient. All these tumors were located in the pancreatic head. Thus, the diagnostic ability of ERP was superior in the head portion, where recognition of a tumor is often difficult at the operation, and a more complicated procedure is required for removal. Nonfunctioning islet cell tumors were localized by hypervascularity on angiogram, but retroperitoneal leiomyosarcoma remained to be excluded in one patient. ERP with an indwelling balloon catheter revealed the pancreatic origin of the tumors and precisely determined the line of pancreatic resection by vividly visualizing pancreatic duct obstruction and intact distal branches. We conclude that ERP is helpful to localize functioning islet cell tumors of the pancreas especially in the head portion and plays an important role for planning resection of nonfunctioning islet cell tumors.     

内镜超声检查术对胰腺肿瘤早期诊断的价值

目的探讨内镜超声检查术（EUS）、管内超声检查术（IDUS）及超声内镜引导下细针穿刺术（EUS-FNA）对胰腺肿瘤早期诊断的价值。方法回顾性分析和比较188例胰腺小占位病灶的EUS、IDUS、EUS—FNA及其他影像学检查结果。结果（1）EUS诊断小胰腺癌的准确率是95．6％（44／46）,优于B超58．6％（27／46）、CT77．4％（24／31）、MRI76．2％（16／21）及内镜逆行胰胆管造影术（ERCP）85．3％（29／34）。小胰腺癌EUS声像图主要表现为类圆形、边界清楚、边缘不规则的低回声肿块,内部回声多均匀。（2）25例胰腺小占位病灶行IDUS检查,其准确率是100．0％（25／25）,明显优于B超32．0％（8／25）、CT52．9％（9／17）及MRI57．9％（11／19）等检查。（3）18例胰腺小占位病灶行EUS—FNA,其准确率是66．7％（12／18）。（4）EUS诊断胰腺假性囊肿的准确率是100．0％（27／27）,明显优于13超52．0％（13／25）、CT66、7％（12／18）、MRI82．4％（14／17）及ERCP78．9％（15／19）;对胰腺囊性肿瘤分类鉴别诊断总的准确率是57．7％（15／26）,优于B超19．2％（5／26）、CT36．4％（8／22）、MRI37．5％（6／16）及ERCP50．0％（7／14）等检查。结论EUS、IDUS及EUS-FNA对胰腺肿瘤的早期诊断具有重要价值。     

EUS-guided rendezvous drainage of obstructed biliary and pancreatic ducts: Report of 6 cases

BACKGROUND: Only a few cases have been reported of EUS-guided drainage of obstructed pancreatic or bile ducts. An initial experience with EUS-guided rendezvous drainage after unsuccessful ERCP is reported. METHODS: EUS-guided transgastric or transduodenal needle puncture and guidewire placement through obstructed pancreatic (n=4) or bile (n=2) ducts was attempted in 6 patients. Efforts were made to advance the guidewire antegrade across the papilla or surgical anastomosis. If guidewire passage was successful, rendezvous ERCP with stent placement was performed immediately afterward. RESULTS: EUS-guided duct access and intraductal guidewire placement was accomplished in 5 of 6 cases, with successful traversal of the obstruction, and rendezvous ERCP, with stent placement in 3 of 6 cases (two biliary, one pancreatic). The procedure was clinically effective in all successful cases (two patients with malignant obstructive jaundice, one with relapsing pancreatitis after pancreaticoduodenectomy). There was one minor complication (transient fever) but no pancreatitis or duct leak after successful or unsuccessful procedures. CONCLUSIONS: EUS is a feasible technique for allowing rendezvous drainage of obstructed biliary or pancreatic ducts through native papillae or anastomoses after initially unsuccessful ERCP.     

Preoperative diagnosis of bile duct strictures--comparison of intraductal ultrasonography with conventional endosonography

BACKGROUND: The accuracy of intraductal ultrasonography (IDUS) and endoscopic ultrasonography (EUS) were compared in diagnosing biliary obstruction and in predicting surgical resectability. METHODS: Fifty-six patients with biliary obstruction were investigated preoperatively with both conventional EUS and IDUS. The ultrasonographic miniprobe was inserted into the bile duct system through the working channel of the duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). Conventional endosonography was performed with echoendoscopes in a standard technique. Images of endoluminal ultrasonography were prospectively reviewed and compared with intraoperative findings and resection specimen analyses. RESULTS: IDUS exceeded EUS in terms of accuracy (IDUS, 89.1%; EUS, 75.6%; P < 0.002), sensitivity (IDUS, 91.1%; EUS, 75.7%; P < 0.002), specificity (IDUS, 80%; EUS, 75%; NS), and T-staging (IDUS, 77.7%; EUS, 54.1%; P < 0.001). In bile duct carcinomas the accuracy rate for lymph node staging using IDUS (60%) is comparable with that using EUS (62.5%). In pancreatic carcinomas, however, lymph node staging using IDUS (13.3%) is significantly (P < 0.002) inferior to EUS (69.2%). Endoluminal ultrasonography may predict the potential resectability of bile duct tumors (IDUS, 81.8%; EUS, 75.6%; P < 0.002). CONCLUSIONS: IDUS proved to be accurate in preoperative diagnosing and T-staging of malignant biliary strictures, whereas it is not suitable for lymph node staging. IDUS using miniprobes during ERCP exceeds conventional EUS in terms of depiction of bile duct obstruction, diagnostic accuracy, and sensitivity and in the prediction of surgical tumor resectability. Additionally, different to EUS, IDUS can conveniently be performed during ERCP in one and the same session.     

Preoperative Diagnosis of Bile Duct Strictures-Comparison of Intraductal Ultrasonography with Conventional Endosonography

Background: The accuracy of intraductal ultrasonography (IDUS) and endoscopic ultrasonography (EUS) were compared in diagnosing biliary obstruction and in predicting surgical resectability. Methods: Fifty-six patients with biliary obstruction were investigated preoperatively with both conventional EUS and IDUS. The ultrasonographic miniprobe was inserted into the bile duct system through the working channel of the duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). Conventional endosonography was performed with echoendoscopes in a standard technique. Images of endoluminal ultrasonography were prospectively reviewed and compared with intraoperative findings and resection specimen analyses. Results: IDUS exceeded EUS in terms of accuracy (IDUS, 89.1%; EUS, 75.6%; P &lt; 0.002), sensitivity (IDUS, 91.1%; EUS, 75.7%; P &lt; 0.002), specificity (IDUS, 80%; EUS, 75%; NS), and T-staging (IDUS, 77.7%; EUS, 54.1%; P &lt; 0.001). In bile duct carcinomas the accuracy rate for lymph node staging using IDUS (60%) is comparable with that using EUS (62.5%). In pancreatic carcinomas, however, lymph node staging using IDUS (13.3%) is significantly (P &lt; 0.002) inferior to EUS (69.2%). Endoluminal ultrasonography may predict the potential resectability of bile duct tumors (IDUS, 81.8%; EUS, 75.6%; P &lt; 0.002). Conclusions: IDUS proved to be accurate in preoperative diagnosing and T-staging of malignant biliary strictures, whereas it is not suitable for lymph node staging. IDUS using miniprobes during ERCP exceeds conventional EUS in terms of depiction of bile duct obstruction, diagnostic accuracy, and sensitivity and in the prediction of surgical tumor resectability. Additionally, different to EUS, IDUS can conveniently be performed during ERCP in one and the same session.     

A Case of Non-Alcoholic Pancreatitis Treated with Steroid Followed-up Using Intraductal Ultrasonography and Endoscopic Retrograde Pancreatography

A 42-year-old man with jaundice was found to have a pancreatic mass in the head by ultrasonography. Endoscopic retrograde cholangiopancreatography (ERCP) showed a segmental narrowing of the main pancreatic duct (MPD) with a mild upstream dilatation and an extrinsic stenosis of the inferior common bile duct (CBD). lntraductal ultrasonography (IDUS) showed a diffuse hypoechoic area with echogenic spots surrounding the narrowed MPD and the stenotic CBD. He was suspected of having autoimmune pancreatitis because of a characteristic pancreatogram, and 30 mg/day predniso-lone was started. Two weeks later, the narrowing of the MPD and the stenosis of the CBD improved dramatically. But the hypoechoic area remained separate from the MPD with a fine reticular pattern on the inside. It completely disappeared in the eighth week. The diachronic changes in the IDUS were characteristic in that the hypoechoic area, which initially surrounded the MPD, disappeared near the MPD, followed by a distant area. This might explain the discrepancy between the images of ERCP and IDUS in the second week of steroid therapy.     

Endoluminal ultrasonography for pancreatic diseases.

Endoluminal ultrasonography was performed on 146 patients with pancreatobiliary diseases by using high-frequency, thin ultrasonic probes, and the usefulness of the new technique in diagnosis of pancreatic diseases was reported. The ultrasound probe could be inserted into the main pancreatic duct in 43 of 46 patients (93.5%), and images of the lesions could be obtained in 42 patients (91.3%). Endoluminal ultrasonography revealed a hypoechoic mass with clear margins and central echogenicity in patients with pancreatic carcinoma. Endoluminal ultrasonography showed normal pancreatic parenchyma as a fine reticular pattern and did not reveal the tumors surrounding the stenosis in patients with focal pancreatitis. Endoluminal ultrasonography in patients with intraductal papillary adenocarcinoma of the pancreas revealed cystic lesions with mural nodules more than 4 mm, mucus echoes, and solid tumors with mixed echo patterns. There were no severe complications, and acute pancreatitis occurred in none of 46 patients, but high-level serum amylase after examination occurred in 5 patients (10.9%). Endoluminal ultrasonography is useful for differential diagnosis in patients with small pancreatic tumors or cystic lesions, especially intraductal papillary tumors of the pancreas. Endoluminal ultrasonography is recommended as a precise examination for the diagnosis of cystic lesions of the pancreas or stenosis of the main pancreatic duct after ERCP and EUS.     

Endoscopic ultrasonography in diagnosis and staging of pancreatic cancer

The accuracy of endoscopic ultrasonography (EUS) for diagnosis of pancreatic cancers was evaluated in consecutive 232 patients with possible pancreatic cancer, and that for assessment of their locoregional spread was evaluated in 28 patients with pancreatic cancer subjected to pancreatectomy, in comparison with the accuracies of transabdominal ultrasonography (US) and computed tomography (CT). EUS was found to be significantly more accurate than US or CT and was especially useful for detecting small pancreatic cancers of less than 2 cm in diameter. With EUS, pancreatic cancers could be detected as a hypoechoic mass with a relatively unclear margin and irregular internal echoes. EUS was also more sensitive than CT and US for detecting venous and gastric invasions: it was more useful for detecting direct invasion of pancreatic cancers when the tumors were less than 3 cm in diameter. These findings indicate that EUS is an accurate method for diagnosis of pancreatic cancer and assessment of their locoregional spread and is particularly useful for detecting small tumors.     

Endosonographic differentiation of benign and malignant stromal cell tumors

Background: Endosonography (EUS) is a valuable technique for diagnosing gastrointestinal stromal cell tumors. However, EUS features that are predictive of malignancy in these tumors have not been defined. Methods: Videotapes and photographs of EUS examinations performed prior to surgical resection of 35 stromal cell tumors (9 malignant) were blindly reviewed by a single examiner. EUS features associated with malignancy were determined. Interobserver agreement in interpreting these features was then measured among a panel of five expert endosonographers who judged EUS videotapes of 35 resected stromal cell tumors (10 malignant). Results: Stepwise logistic regression analysis demonstrated that tumor size (diameter > 4 cm), irregular extraluminal border, echogenic foci, and cystic spaces were independently associated with malignancy in stromal cell tumors (p < 0.05). Interobserver agreement for irregular extraluminal border, echogenic foci, and cystic spaces, as measured by mean kappa statistic, was 0.43, 0.39, and 0.28, respectively. For the five experts, the sensitivity for detecting malignancy ranged between 80% to 100% when at least two of the three features were judged to be present. The likelihood of finding malignancy ranged between 0% to 11% for the experts when all three features were judged absent. Conclusions: Tumor size and certain EUS features are useful for predicting malignancy in stromal cell tumors. Absence of these features indicates benign disease. Agreement among experts in interpreting these EUS features is fair to moderate. (Gastrointest Endosc 1997;45:468-73.)     

Endoscopic approach for diagnosing autoimmune pancreatitis

It is of utmost importance to differentiate autoimmune pancreatitis (AIP) from pancreatic cancer (PC). Segmental AIP cases are sometimes difficult to differentiate from PC. On endoscopic retrograde cholangiopancreatography, long or skipped irregular narrowing of the main pancreatic duct (MPD), less upstream dilatation of the distal MPD, side branches derived from the narrowed portion of the MPD, absence of obstruction of the MPD, and stenosis of the intrahepatic bile duct suggest AIP rather than PC. Abundant infiltration of IgG4-positive plasma cells is frequently and rather specifically detected in the major duodenal papilla of AIP patients. IgG4-immunostaining of biopsy specimens obtained from the major duodenal papilla is useful for supporting a diagnosis of AIP with pancreatic head involvement. On endoscopic ultrasonography (EUS), hyperechoic spots in the hypoechoic mass and the duct-penetrating sign suggest AIP rather than PC. EUS and intraductal ultrasonography sometimes show wall thickening of the common bile duct even in the segment in which abnormalities are not clearly observed with cholangiography in AIP patients. EUS-guided fine needle aspiration, especially EUS-guided Tru-Cut biopsy, is useful to diagnose AIP, as well as to exclude PC.     

Endoscopic ultrasound and fine-needle aspiration of unexplained bile duct strictures

OBJECTIVES: The aim of this study was to assess the utility of endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) in patients with unexplained common bile duct strictures after endoscopic retrograde cholangiopancreatography (ERCP) and intraductal tissue sampling. METHODS: Records were reviewed for all subjects undergoing EUS for evaluation of unexplained bile duct strictures at our institution. 40 subjects had either a final histologic diagnosis (24) or no evidence of malignancy after at least 1 yr of follow-up (16). RESULTS: The finding of a pancreatic head mass and/or an irregular bile duct wall had sensitivity for malignancy of 88%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 84%. Bile duct wall thickness >/=3 mm had a sensitivity for malignancy of 79%, specificity of 79%, positive predictive value of 73%, and negative predictive value of 80%. Sensitivity of EUS FNA for malignancy was 47% with specificity 100%, positive predictive value 100%, and negative predictive value 50%. CONCLUSIONS: Sonographic features may be more sensitive than EUS FNA for diagnosis of unexplained bile duct strictures and include presence of a pancreatic mass, an irregular bile duct wall, or bile duct wall thickness > 3 mm. EUS FNA cytology is specific but insensitive for diagnosis. EUS improves the diagnosis of otherwise unexplained bile duct strictures.     

EUS findings in patients with autoimmune pancreatitis

BACKGROUND: Autoimmune pancreatitis is an increasingly recognized benign condition with a presentation similar to pancreatic neoplasia but responds to corticosteroid therapy. Clinical features, ERCP, and CT findings have been described. This study assessed the EUS and EUS-guided FNA features of proven autoimmune pancreatitis. METHODS: The diagnosis of autoimmune pancreatitis was based on examination of surgical resection specimens or typical clinical findings (elevated immunoglobulin G level, no evidence of malignancy, characteristic non-EUS imaging studies, and clinical improvement, especially in response to treatment with a corticosteroid). RESULTS: Presenting manifestations in 14 patients included obstructive jaundice, abdominal pain, and weight loss. Ten patients underwent surgery (including exploratory surgery). Six were successfully treated with corticosteroid. EUS revealed diffuse hypoechoic pancreatic enlargement (8/14) or a focal irregular hypoechoic mass (6/14). Features of chronic pancreatitis were not noted. EUS-guided FNA of the pancreas was suggestive of chronic inflammatory pancreatitis in 9 of 12 patients. Celiac and peripancreatic lymphadenopathy (up to 3 cm in diameter) was present in 6 patients. EUS-guided FNA of lymph nodes (3/4) did not reveal evidence of malignancy. Vascular involvement was noted in 3 patients. CONCLUSIONS: The EUS features of autoimmune pancreatitis are easily mistaken for malignancy. However, a diffusely hypoechoic, enlarged pancreas, together with chronic inflammatory cells in aspirated cytologic specimens, is supportive of the diagnosis of autoimmune pancreatitis. When combined with clinical data, EUS and EUS-guided FNA may support a diagnosis of autoimmune pancreatitis, may warrant a trial of corticosteroid, and thereby may prevent unnecessary surgery.