Ki-ras oncogene activation in preinvasive pancreatic cancer.

Activation of the Ki-ras oncogene by specific point mutations at codon 12 occurs at a remarkably high frequency in pancreatic ductal adenocarcinoma and is likely to be an important event in the pathogenesis of this cancer. To determine whether ras activation also occurs in noninvasive proliferative lesions of the pancreas, a series of cases of ductal papillary hyperplasia, intraductal papillary neoplasia, and intraduct extensions of ductal adenocarcinoma were examined for activating mutations of Ki-ras at codons 12, 13, and 61 using polymerase chain reaction amplification. Specific mutations at Ki-ras codon 12 were found in 5 of 6 cases (83%) of intraduct extensions of carcinomas and in 12 of 16 (75%) invasive carcinomas. In cases with both intraductal and invasive components, the same mutation was identified in each. No mutations were found in 5 intraductal papillary neoplasms and 9 cases of ductal papillary hyperplasia. The authors conclude that Ki-ras activation at codon 12 is important in the tumorigenesis of ductal adenocarcinoma of the pancreas but is not required in the pathogenesis of ductal papillary hyperplasia or intraductal papillary neoplasm.     

Pancreatic intraductal sampling during ERCP in patients with chronic pancreatitis and pancreatic cancer: cytologic studies and k-ras-2 codon 12 molecular analysis in 47 cases.

BACKGROUND: A preoperative tissue diagnosis of pancreatic cancer is desirable but difficult to obtain. METHODS: Pancreatic brush cytology, salvage cytology, and collection of pancreatic juice were attempted prospectively during ERCP in 34 patients with pancreatic cancer and 11 with chronic pancreatitis. K-ras-2 codon 12 was analyzed for presence and type of point mutations. RESULTS: Brush cytology coupled with salvage cytology had a sensitivity of 74%. The addition of cytologic analysis of pancreatic juice did not substantially improve sensitivity (76%). K-ras-2 was mutated in both cancer (87%) and pancreatitis (40%). The specificity for cytology was 100% and for K-ras-2 mutations 60%. Combining cytology with mutation analysis increased sensitivity to 93% but reduced the positive predictive value. The negative predictive value never exceeded 75%. None of the patients with chronic pancreatitis had cancer develop (median follow-up 60 months). CONCLUSIONS: Pancreatic ductal brushing with salvage cytology is useful in the diagnosis of cancer, whereas cytologic analysis of pancreatic juice can be abandoned. At present, K-ras-2 mutation is not useful for differentiating pancreatic cancer from chronic pancreatitis or the identification of patients with chronic pancreatitis at risk for malignant transformation.     

胰管刷检标本K-ras基因突变检测在胰腺癌诊断中的价值

目的 探讨胰管刷检标本K-ras基因突变检测在胰腺癌诊断中的价值。方法 应用突变富集聚合酶联反应（PCR）－单链构象多态性（SSCP）法，检测胰腺疾病胰管刷检标本K-ras基因第一外显子第12密码子点突变。结果 35例胰管刷检标本PCR扩增均获成功，成功率为100％。20例胰腺癌中14例K-ras突变（70％），7例慢性胰腺炎中1例K-ras突变（14％），两组间差异有显著性（P＜0．05）。胰腺囊腺瘤，十二指肠乳头癌均未见K-ras突变。胰管刷检标本K-ras突变与胰腺癌部位无关。胰管刷检K-ras突变检测诊断胰腺癌的敏感性，特异性和准确性分别为70％，90％和83％。结论 检测胰管刷检标本中K-ras基因突变有助于胰腺癌的诊断，具有良好的临床应用前景。     

Relative contribution of Ki-ras gene analysis and brush cytology during ERCP for the diagnosis of biliary and pancreatic diseases

Background: Ki-ras mutation analysis from material collected during ERCP has been claimed to improve the diagnosis of pancreatic and bile duct carcinomas as compared with conventional cytology. Our aim was to study the relative contribution of both Ki-ras analysis and brush cytology in patients with a significant stricture at ERCP. Methods: Brushings were collected in duplicate for both analyses in 142 patients in whom a definitive diagnosis was obtained by histology or a minimal follow-up of 6 months. Results: For pancreatic strictures, sensitivity, specificity, and accuracy of Ki-ras analysis vs. cytology in detecting malignancy were 81% vs. 66%, 72% vs. 100%, and 70% vs. 74%, respectively. For biliary strictures, they were 25% vs. 42%, 100% vs. 100%, and 35% vs. 43%, respectively. The combination of the two methods only marginally increased their sensitivity and accuracy in both types of strictures. Conclusion: Ki-ras analysis is a sensitive method for diagnosing pancreatic but not biliary carcinoma. However, its specificity is lowered by a high frequency of Ki-ras mutations in patients with chronic pancreatitis (25%) who did not manifest cancer development within a 6-month follow-up period. In pancreatic duct strictures, brush cytology appears to be more specific in detecting malignancy; specificity for Ki-ras and cytology are equivalent for the diagnosis of malignant bile duct strictures. Therefore, making a clinical decision on the sole basis of Ki-ras analysis is probably not justified in the majority of the cases. (Gastrointest Endosc 1998;47:479-85.)     

胰管刷检标本细胞学联合VEGF检测对胰腺癌的诊断价值

目的：研究胰管刷检细胞学和VEGF检测对胰腺癌的诊断价值。方法：应用内镜逆行胰胆管造影（ERCP）下胰管刷检细胞学涂片，分别行HE染色和免疫组化法检测血管内皮生长因子（VEGF）表达，并比较其对胰腺癌的诊断价值。结果：细胞HE染色诊断胰腺癌的敏感性51．9％，特异性为100％。VEGF免疫组化法诊断胰腺癌的敏感性为63．5％，特异性为100％，与HE染色相比差异有显意义（X^2．4．17，P＝0．0412）。细胞学HE染色联合VEGF免疫组化法诊断敏感性为75％，特异性为100％，与单独细胞学HE染色（X^2＝10．08，P＝0．0015）或VEGF检测（X^2＝4．17，P＝0．0412）相比，差异均有显意义。结论：胰管刷检标本细胞学与VEGF检测相结合可显提高胰腺癌的诊断敏感性。     

内镜逆行胰胆管造影下胰管擦拭法细胞学检查对胰腺肿瘤的诊断价值

目的：研究内镜逆行胰胆管造影（ERCP）下胰管擦拭法细胞学检查（简称刷检）对胰腺肿瘤诊断的临床应用价值。方法：在ERCP检查的同时采用胰管细胞刷刷取细胞涂片并结合,ERCP对临床疑诊为胰腺肿瘤的27例患者进行研究。结果：细胞学检查阳性率为55．6％,且头、体部胰腺癌胰管刷检细胞学检查阳性率较高,分别为69．2％和60％,ERCP诊断正确率为77．8％,两者结合诊断正确率达100％,结论：该诊断方法快速,经济实用,安全和准确性高,可与ERCP结合进行,提高胰腺恶性肿瘤的检出率。     

Clinical application of ras gene mutation for diagnosis of pancreatic adenocarcinoma

Most pancreatic adenocarcinomas are known to have ras gene (oncogene) mutations. The site of the mutations is localized in codon 12 of K-ras gene. Such high incidence and localization of the ras gene mutations have not been observed in any other human malignancies. Polymerase chain reaction and direct sequencing method enabled us to analyze DNA sequence around codon 12 of K-ras gene in small quantities of specimens obtained from needle biopsies and aspirate samples for pathological diagnosis. All the materials obtained from 12 patients with pancreatic adenocarcinoma showed the mutations, whereas those obtained from 6 patients with chronic pancreatitis showed no mutations. In several cases using the mutations of K-ras gene as a marker, this analysis supplemented conventional pathology and cytology in making the diagnosis of pancreatic adenocarcinoma. The analysis of ras-gene mutations was useful for the clinical diagnosis of pancreatic adenocarcinoma.     

Ki-ras codon 12 point mutation and p53 mutation in pancreatic diseases.

BACKGROUND/AIMS: The Ki-ras gene located at 12p, encodes the GTP binding protein involving the signal transduction system and concerns cell proliferation and differentiation. METHODOLOGY: Pancreatic tissues were obtained from 37 patients with various pancreatic diseases. Ki-ras codon 12 point mutation and p53 (exon 5-8) mutation were examined in 3 patients with chronic pancreatitis, 9 mucinous adenoma of the pancreas (2 with mucinous cystadenoma and 7 with intraductal papillary-mucinous adenoma), 22 pancreatic ductal carcinoma, and 3 serous cystadenoma. RESULTS: On usual pancreatic exocrine ductal lesions, Ki-ras point mutation was evident in 0% (0/3) of chronic pancreatitis, in 56% (5/9) of mucinous adenoma, and in 57% (12/21) of ductal carcinoma, the mutation being located in the second letter in 18 and in the 1st letter in 2. One Ki-ras codon 12 positive pancreatic cancer showed Ki-ras codon 12 point mutation in the surrounding pancreas (2nd letter mutation in both areas). p53 mutation was present in 0% (0/1) of chronic pancreatitis, in 0% (0/8) of mucinous adenoma, while it was evident in 29% (6/21) of pancreatic ductal carcinoma, the mutation being situated in exon 5 in 3, in exon 6 in 1, and in exon 7 in 2. In 3 patients with serous cystadenoma, there was no mutation in Ki-ras codon 12 or p53 (exon 5-8). CONCLUSIONS: These findings suggest that Ki-ras point mutation is involved in the early events of pancreatic ductal carcinoma, while p53 mutation is intricated in the late phase of pancreatic ductal carcinogenesis and the histogenesis of serous cystadenoma is different from that of pancreatic exocrine ductal lesions including mucinous adenoma and ductal carcinoma.     

Clinical Evaluation of Brushing Cytology and Biopsy of the Pancreatic Duct in Patients with Mucin Producing Tumor of the Pancreas

Abstract: A cytological study of pure pancreatic juice obtained endoscopically after brushing the lesion of the pancreatic duct urns performed in 10 patients with mucin producing tumors of the pancreas. In 6 of these 10 patients, biopsies from the lesion in the pancreatic duct were also carried out endoscopically. The brushing cytology in all 6 patients with mucin producing carcinoma of the pancreas, except for the sidebranch type, showed cellular atypism and the cytological diagnoses were Class IV or Class V. The results of the brushing cytology in the patients assumed clinically benign were Class I ? Class III. Biopsy results in 4 patients with mucin producing carcinoma of the pancreas indicated that one of them had adenocarcinoma, and the other 3 had atypical hyperplasia which suggests the existence of malignancy. In the patient with adenoma, diagnosis of the biopsy specimen revealed hyperplasia only. It was concluded that cytology and biopsy of lesions in the pancreatic duct are a valuable way of assessing mucin producing tumors of the pancreas before surgery.     

Screening for early pancreatic neoplasia in high-risk individuals: a prospective controlled study.

BACKGROUND & AIMS: Individuals with a strong family history of pancreatic cancer and persons with Peutz-Jeghers syndrome (PJS) have an increased risk for pancreatic cancer. This study screened for early pancreatic neoplasia and compared the pancreatic abnormalities in high-risk individuals and control subjects. METHODS: High-risk individuals with PJS or a strong family history of pancreatic cancer were prospectively evaluated with baseline and 12-month computed tomography (CT) scan and endoscopic ultrasonography (EUS). If EUS was abnormal, EUS-fine-needle aspiration and endoscopic retrograde cholangiopancreatography (ERCP) were performed. Surgery was offered to patients with potentially neoplastic lesions. Radiologic findings and pathologic diagnoses were compared. Patients undergoing EUS and/or ERCP for benign non-pancreatic indications were concurrently enrolled as control subjects. RESULTS: Seventy-eight high-risk patients (72 from familial pancreatic cancer kindreds, 6 PJS) and 149 control patients were studied. To date, 8 patients with pancreatic neoplasia have been confirmed by surgery or fine-needle aspiration (10% yield of screening); 6 patients had 8 benign intraductal papillary mucinous neoplasms (IPMNs), 1 had an IPMN that progressed to invasive ductal adenocarcinoma, and 1 had pancreatic intraepithelial neoplasia. EUS and CT also diagnosed 3 patients with 5 extrapancreatic neoplasms. At EUS and ERCP abnormalities suggestive of chronic pancreatitis were more common in high-risk patients than in control subjects. CONCLUSIONS: Screening EUS and CT diagnosed significant asymptomatic pancreatic and extrapancreatic neoplasms in high-risk individuals. IPMN should be considered a part of the phenotype of familial pancreatic cancer. Abnormalities suggestive of chronic pancreatitis are identified more commonly at EUS and ERCP in high-risk individuals.     

Assessment of endoscopic retrograde cholangio-pancreatography (ERCP) and pure pancreatic juice cytology in patients with pancreatic disease.

Pure pancreatic juice has been collected from 61 patients at the time of endoscopic retrograde cholangio-pancreatography (ERCP) for the purpose of cytodiagnosis. The ERCP and cytological findings are discussed. Pure pancreatic juice cytology may help in the interpretation of the pancreatogram in both pancreatitis and pancreatic carcinoma. In patients with pancreatic carcinoma, ERCP alone was diagnostic in 65%, cytology alone in 54%. By combining these two approaches, a diagnostic result was obtained in 92% of patients.     

Clinical usefulness of K-ras gene mutation detection and cytology in pancreatic juice in the diagnosis and screening of pancreatic cancer.

BACKGROUND: The significance of K-ras codon 12 mutation in pancreatic juice is still unclear. Although considerable controversy surrounds this question, the diagnostic utility of K-ras in patients with clinical suspicion of pancreatic cancer (PC) and in PC-risk patients remains unknown. OBJECTIVE: To study prospectively the utility of the K-ras gene mutation and cytology in the diagnosis and screening of PC, and to assess its contribution to clinical decision making. METHODS: Pancreatic juice samples obtained from 90 patients were evaluated prospectively. Group I (n = 40) comprised patients with clinical suspicion of PC; group II (n = 50) comprised 49 patients with chronic pancreatitis and one patient proceeding from a PC family screening. The K-ras mutation was detected by means of artificial restriction fragment length polymorphisms (RFLP) in DNA after polymerase chain reaction (PCR) amplification. RESULTS: In group I, of those patients with a definitive diagnosis of PC, malignant cells were found in 27% and K-ras mutation in 44%. In five cases, molecular analysis contributed to diagnosis (4/11 with negative cytology and 1/2 with insufficient cytological material). K-ras mutation revealed an early tumour in one patient, and was the only sample available for diagnosis in another. In group II, the K-ras gene mutation was detected in 8/49 patients (16%) with chronic pancreatitis, one of whom developed PC (2%). CONCLUSIONS: K-ras mutation analysis of pancreatic juice may complement cytological evaluation in the diagnosis of PC, in spite of its limited contribution to clinical decision making. The presence of K-ras mutation in chronic pancreatitis classifies a subgroup of PC-risk patients who should be evaluated carefully by long-term follow-up.     

Detection of K-ras point mutation and telomerase activity during endoscopic retrograde cholangiopancreatography in diagnosis of pancreatic cancer

AIM: To study the value of monitoring K-ras point mutation at codon 12 and telomerase activity in exfoliated cells obtained from pancreatic duct brushings during endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic cancer. METHODS: Exfoliated cells obtained from pancreatic duct brushings during ERCP were examined in 27 patients: 23 with pancreatic cancers, 4 with chronic pancreatitis. K-ras point mutation was detected with the polymerase chain reaction and restriction fragment-length polymorphism (PCR-RFLP). Telomerase activity was detected by PCR and telomeric repeat amplification protocol assay (PCR-TRAP-ELISA). RESULTS: The telomerase activities in 27 patients were measured in 21 exfoliated cell samples obtained from pancreatic duct brushings. D450 value of telomerase activities in pancreatic cancer and chronic pancreatitis were 0.446+/-0.27 and 0.041+/-0.0111, respectively. Seventy-seven point eight percent (14/18) of patients with pancreatic cancer and none of the patients with chronic pancreatitis showed telomerase activity in cells collected from pancreatic duct brushings when cutoff value of telomerase activity was set at 2.0. The K-ras gene mutation rate (72.2%) in pancreatic cancer was higher than that in chronic pancreatitis (33.3%) (P<0.05). In considering of both telomerase activities and K-ras point mutation, the total positive rate was 83.3%(15/18), and the specificity was 100%. CONCLUSION: Changes of telomerase activities and K-ras point mutation at codon 12 may be an early event of malignant progression in pancreatic cancer. Detection of telomerase activity and K-ras point mutation at codon 12 may be complementary to each other, and is useful in diagnosis of pancreatic cancer.     

Utility of pancreatic duct brushing for diagnosis of pancreatic carcinoma

Background The aim of this study was to evaluate the usefulness of pancreatic duct brushing for diagnosis of pancreatic carcinoma. Methods Brush cytology was attempted in 58 patients suspected of having pancreatic malignancy because of stricture of the main pancreatic duct, confirmed by endoscopic retrograde cholangiopancreatography. Thirty-eight patients were finally diagnosed by an operation or the clinical course as having pancreatic carcinoma, and the remaining 20 patients as having chronic pancreatitis. The usefulness of brush cytology for diagnosis of pancreatic carcinoma was estimated. We interpreted failures of pancreatic duct brushing to be false negatives when the lesion was malignant. Results In 48 of 58 patients (82.8%), brushing was successfully performed and satisfactory specimens were obtained. Brush cytology was positive in 25 of 38 patients with pancreatic carcinoma (sensitivity 65.8%) and negative in all patients without malignancy (specificity 100%). Overall accuracy was 76.4%. During 2001–2005, the number of back-and-forth motions of the brush was increased to more than 30 times. The sensitivity significantly improved from 43.8% in 1997–2000 to 81.8% in 2001–2005 (P < 0.05). The increased success rate of brushing by improvement of skill in manipulating the guidewire and increased number of cells smeared on glass slides by increased back-and-forth motion of the brush may account for this improvement over time. Moreover, the sensitivity in 2001–2005 was 85.7% if failures of brushing with pancreatic carcinoma are excluded. No major complications occurred, except for two patients with a moderate grade of acute pancreatitis. Conclusions Although further studies with a large number of patients are needed, our results suggest that with recent improvements of the brushing technique, pancreatic duct brushing is a useful and safe method for the differential diagnosis of malignancy from benign diseases of the pancreas.     

Intraductal pancreatic carcinoma associated with pancreas divisum.

OBJECTIVE: we report the case of a 36 years old man with a pancreatic cancer associated to a pancreas divisum presenting as acute and relapsing recurrent pancreatitis. The coexistence of intraductal carcinoma and pancreas divisum is uncommon as let us do analyze its clinical, radiological and therapeutical features. CONCLUSIONS: 1. Pancreatic duct obstruction and pancreas divisum as congenital anomaly may be consider potential etiologies for pancreatic cancer. 2. Widespread use of magnetic resonance xholangiopancreatography and endoscopic retrograde xholangiopancreatography examinations together with brush cytology smears will allow more accurate approach to tumor diagnosis and management. 3. The use of pancreatoscopy in patients suffering from chronic pancreatitis may reveal helpful to discover intraductal neoplasms otherwise misdiagnosed.     

Diagnosis of pancreatic cancer by cytology and measurement of oncogene and tumor markers in pure pancreatic juice aspirated by endoscopy

BACKGROUND/AIMS: Cytological examination of pancreatic juice is useful in the diagnosis of an occult cancer of the pancreas. The early diagnosis of pancreatic carcinoma using traditional radiographic or ultrasonographic methods is extremely difficult. METHODOLOGY: In order to detect an early pancreatic cancer, cytological examination, measurement of tumor marker, and detection of K-ras point mutation were performed using the samples of pure pancreatic juice aspirated endoscopically in patients who had symptoms or findings that suggested pancreatic disease. RESULTS: By routine ERP-cytology, positive cytologic results were obtained in 15 (4%) out of 359 patients without a mass. With the aid of intra-operative cytodiagnosis, all 15 occult neoplasms of the pancreas were successfully resected. One patient died from another disease without evidence of recurrence. However, the other patients were alive with no evidence of recurrence for an average of 5.5 years following surgery. The patients who had negative ERP-cytology results were observed, but no further cases of pancreatic cancer were found. The CEA levels in the pure pancreatic juice were significantly higher in patients with pancreatic cancer than in those with pancreatitis. K-ras point mutation at codon 12 was detected not only in cases of pancreatic cancer, but also in cases of chronic pancreatitis as well as control subjects. CONCLUSIONS: Cytological examination of pancreatic juice is useful in the diagnosis of an early and potentially curable in situ cancer of the pancreas. The CEA levels in the pure pancreatic juice provided useful information for differentiating the pancreatic cancer from chronic pancreatitis. K-ras point mutation at codon 12 in pancreatic juice was considered to be useful in identifying patients at high risk for the development of pancreatic cancer.     

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.     

内镜下胰腺细胞学检查方法对胰腺肿瘤的诊断价值

目的　探讨内镜下胰腺细胞学检查对胰腺肿瘤诊断的临床应用价值 ,提高对胰腺恶性肿瘤的检出率。方法　在ERCP检查的同时采用胰管细胞刷及放置鼻胰管方法对 47例患者进行研究。结果　刷检细胞学检查准确性为 70 4% ,敏感性为 65 2 % ,特异性为 10 0 % ;胰液细胞学准确性为 45 % ,敏感性为 8 3 %及特异性10 0 %。结论　该检查方法快速 ,经济实用 ,安全和准确性高 ,不失为胰腺肿瘤早期诊断的一种可靠且有价值的检查手段。     

Clinical significance of cathepsin E in pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma

BACKGROUND: It has been reported that cathepsin E (CTSE) is a non-secretory and intracellular aspartic proteinase found in the superficial epithelial cells of the stomach and that it is also expressed in pancreatic ductal adenocarcinoma. We evaluated the diagnostic value of CTSE in the pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma compared with that of CA19-9, carcinoembryonic antigen (CEA) and K-ras mutations. METHODS: One hundred and one patients (25 with pancreatic ductal adenocarcinoma and 76 with chronic pancreatitis) were examined for the diagnostic significance of CTSE in the pancreatic juice in the diagnosis of pancreatic ductal adenocarcinoma. Forty of 101 patients (15 with pancreatic ductal adenocarcinoma and 25 with chronic pancreatitis) were examined to compare the diagnostic value of various tumor markers in the pancreatic juice, namely CA19-9, CEA, K-ras mutations and CTSE. RESULTS: The detection frequency of CTSE was significantly higher in patients with pancreatic ductal adenocarcinoma (64.0%) than in patients with chronic pancreatitis (7.9%; chi2 = 34.76; P < 0.0001). The sensitivity, specificity and diagnostic accuracy of CTSE in the pancreatic juice for pancreatic ductal adenocarcinoma was 66.7, 92.0 and 82.5%, respectively. These values were more efficient in comparison with those of CA19-9, CEA and K-ras mutations. The main cause of the detection failure of CTSE in pancreatic ductal adenocarcinoma was obstruction of the main pancreatic duct. Sensitivity was 85.7% in patients without obstruction of the main pancreatic duct. CONCLUSIONS: Cathepsin E in the pancreatic juice is a novel marker for a definitive diagnosis of pancreatic ductal adenocarcinoma.     

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.