Surgical treatment of intraductal papillary-mucinous tumors of the pancreas

BACKGROUND/AIMS: IPMT (Intraductal papillary-mucinous tumor of the pancreas) is increasingly recognized. The aim of this study was to investigate the appropriate surgical treatment for these tumors. METHODOLOGY: Between January 1981 and September 1998, 62 patients with IPMT underwent surgery. We retrospectively examined the clinicopathological features and surgical outcomes of the patients. RESULTS: The types of IPMT were as follows: hyperplasia (20); adenoma (31); and carcinoma, both invasive (5) and noninvasive (6). Lymph node metastasis was found in 36% of the carcinomas. The size of mural nodules was more than 3 mm in all adenoma or carcinoma cases, while the percentage of hyperplasia less than 3 mm was 75%. Intraoperative pancreatoscopy and annular array ultrasonography were very useful, because they detected 10 lesions that could not be found by preoperative examinations, such as computed tomography, endoscopic retrograde pancreatography, and endoscopic ultrasonography. All patients underwent surgical resection, including 10 pancreaticoduodenectomies (Whipple's procedure), 10 pylorus-preserving pancreaticoduodenectomies, 13 pancreatic head resections with segmental duodenectomies, 17 distal pancreatectomies, 9 segmental resections of the pancreas, 2 duodenum-preserving pancreatic head resections, and 1 total pancreatectomy. No operative or hospital death was observed. The postoperative survival rate at 5 years was 71.6% for carcinoma in IPMT. All of the cases with hyperplasia, adenoma and noninvasive carcinoma survived. Only two of the patients with invasive carcinoma died. CONCLUSIONS: IPMT had a favorable prognosis, as compared with pancreatic duct carcinoma. When selecting a surgical procedure for treating these tumors, it is important to confirm the tumor extent, as well as the diagnosis of invasion or noninvasion. In cases with invasion, radical resection is required. On the other hand, organ-function-preserving procedures should be selected for diseases without invasion.     

Differential diagnosis of intraductal papillary‐mucinous tumor of the pancreas by endoscopic ultrasonography and intraductal ultrasonography

Background: Intraductal papillary‐mucinous tumor (IPMT) of the pancreas has a broad spectrum of histology ranging from hyperplasia to adenocarcinoma. Therefore, it is important to differentiate between the malignant and benign lesions to determine the therapeutic strategy for IPMT. Patients and Methods: Thirty‐nine patients with IPMT (27 men and 12 women, mean age: 63.3 years) underwent surgery between January 1985 and March 2002. The size of the cystic lesion, the maximum diameter of the main pancreatic duct (MPD), and the height of the papillary tumor inside the cyst were investigated by endoscopic ultrasonography (EUS) and/or intraductal ultrasonography (IDUS) before operation. These preoperative clinical findings were compared with the pathological findings of the resected specimen. Results: The size of the cystic lesion, the diameter of MPD, and the height of the papillary tumor in cases with malignant IPMT (invasive and non‐invasive carcinoma) were larger than those in cases with benign IPMT (adenoma and hyperplasia). Analysis of the images of the lesions revealed that the following three factors are important for diagnosing IPMT: (i) the size of the cystic lesion is ≥ 30 mm; (ii) the diameter of MPD is ≥ 8 mm; (iii) the height of the papillary tumor inside the cyst is ≥ 3 mm. It was not significant to differentiate between benign and malignant IPMT based on factor (i), but statistically significant (P < 0.001) based on factors (ii) and (iii). Conclusions: EUS and IDUS are useful in the differential diagnosis of IPMT, especially in the differentiation between malignant and benign IPMT.     

Endosonographic diagnosis of intraductal papillary‐mucinous pancreatic tumors by intraductal ultrasonography

Background: Intraductal papillary‐mucinous pancreatic tumors (IPMT) are intraductal lesions formed by mucin‐producing epithelium, which proliferates in a papillary pattern, and presents a spectrum from hyperplasia to adenocarcinoma. The value of intraductal ultrasonography (IDUS) for excluding malignancy has not been assessed in a case series previously. Methods: Intraductal ultrasonography was performed in 17 patients with IPMT (12 with adenocarcinoma and five with adenoma) between November 1993 and June 2002. Intraductal ultrasonography was used to determine the maximum height and maximum cross‐sectional area of protruding lesions. Results were compared after dividing the tumors into three groups: a benign lesion group, a non‐invasive cancer group, and an invasive cancer group. The resection line was located over 10 mm from the edge of the protruding lesion visualized by intraductal ultrasonography. Results: All adenocarcinomas had a height ≥ 5 mm and all benign lesions had a height ≤ 3 mm, with this difference being significant (P = 0.0034). The height of non‐invasive and invasive cancer was similar. The maximum cross‐sectional area of the protrusion was smaller for benign lesions (≤ 15 mm²) than for non‐invasive cancer (≥ 34 mm², P = 0.0034). The cross‐sectional area of the protrusion was greater in patients with invasive cancer than in those with non‐invasive cancer (P = 0.0367). All surgical margins have remained clear and no patient has suffered from a recurrence during 1 to 8 years of follow‐up computed tomography and ultrasonography. Conclusions: Intraductal ultrasonography can distinguish benign from malignant IPMT based on the height and maximum cross‐sectional area of the protruding tumor.     

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.     

IDUS IN THE DIAGNOSIS OF IPMT

Intraductal papillary mucinous tumor of the pancreas (IPMT) is considered as having low‐grade malignant potential, and malignancy is not infrequent. Therefore, accurate diagnosis is indispensable for appropriate patient care. IPMT is classified mainly into two categories based on the distribution of tumor, the main duct type and the branch duct type. In the diagnosis of IPMT, there are four important points: differentiation of IPMT from other pancreatic pathologies; differentiation of malignancy from benign lesions; evaluation of tumor extent along the MPD; and investigation of duct cell carcinoma coexistent with or derived from IPMT. IPMT should be distinguished from chronic pancreatitis, ductal adenocarcinoma, or cystic neoplasms. IPMT often requires pancreaticoduodenectomy for cure, but such invasive surgery should be avoided in patients with benign hyperplasia. Mural nodules in the MPD can be clearly visualized by intraductal ultrasonography (IDUS). Measurement of the height of the tumor mass by IDUS is useful in distinguishing benign from malignant IPMT. Intraductal spread of IPMT along the MPD is demonstrated by IDUS as irregular thickening of the MPD wall. To achieve a tumor‐free margin in surgery, evaluation by IDUS of the extent of the tumor along the MPD is important. The expected accuracy of IDUS in the diagnosis of invasive IPMT is reportedly over 90%.     

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.     

Accuracy of EUS for detection of intraductal papillary mucinous tumor of the pancreas

BACKGROUND: Patients with intraductal papillary mucinous tumors of the pancreas (IPMT) present with symptoms similar to those of chronic pancreatitis. This study assessed the accuracy of EUS for detection of IPMT and identified features that discriminate IPMT from chronic pancreatitis. METHODS: EUS accuracy for detecting IPMT was determined with characteristic findings by endoscopic retrograde pancreatography as the reference standard. To determine EUS features characteristic of IPMT, EUS images from patients with IPMT were compared with those from patients (similar age, gender) with chronic pancreatitis. RESULTS: Thirty-eight patients (23 men, 15 women; age range 40-90 years) with IPMT were identified between 1994 and 2001. For EUS, the sensitivity was 86%, specificity 99%, positive predictive value 78%, and negative predictive value 99% for detection of IPMT. When compared with patients with chronic pancreatitis, the EUS features of dilation of pancreatic duct (89% vs. 42%, p < 0.0001), cysts (45% vs. 11%, p = 0.002), and pancreatic atrophy (32% vs. 3%, p = 0.002) were more common, whereas parenchymal features of chronic pancreatitis were less common with IPMT (21% vs. 97%, p < 0.0001). By multivariate analysis, the presence of no more than one parenchymal feature of chronic pancreatitis suggested the diagnosis of IPMT (odds ratio 43.84; 95% CI [4.13, 465.74]). CONCLUSIONS: EUS may be useful in the initial evaluation of patients suspected to have IPMT. Paucity of parenchymal features of chronic pancreatitis is important in differentiating IPMT from other causes of chronic pancreatitis.     

Endoscopic diagnosis of pancreatic cancer using intraductal ultrasonography

BACKGROUND/AIMS: At present developed modalities are not sufficient for detecting early stage pancreatic cancer. We previously reported the clinical usefulness of intraductal ultrasonography in various pancreatobiliary diseases. In the present study we assessed the usefulness of intraductal ultrasonography in diagnosing pancreatic cancer. METHODOLOGY: Thirty-one patients with pancreatic cancer were examined by intraductal ultrasonography. We approached the main pancreatic duct (pancreatic duct-intraductal ultrasonography) in 24 of 31 patients and the bile duct (bile duct-intraductal ultrasonography) in 20 patients with pancreatic cancer. We compared the diagnostic ability of pancreatic duct-intraductal ultrasonography with that of extracorporeal ultrasonography, computed tomography, endoscopic ultrasonography or endoscopic retrograde pancreatography. We examined the usefulness of bile duct-intraductal ultrasonography in diagnosing tumor invasion to the bile duct. RESULTS: Pancreatic duct-intraductal ultrasonography was able to demonstrate a tumor in 22 of 24 patients. Extracorporeal ultrasonography, computed tomography, endoscopic ultrasonography or endoscopic retrograde pancreatography detected tumors in 26, 27, 29, 29 of 31 patients, respectively. In two patients, only intraductal ultrasonography could demonstrate a tumor, which was not detected by any other modalities. We examined bile duct invasion of the tumor according to our grading system. The overall accuracy rate was 90%. No complications were noted in any patients throughout the study period. CONCLUSIONS: Intraductal ultrasonography is useful to diagnose pancreatic cancer, and it is suggested that it should be actively performed after endoscopic retrograde pancreatography.     

Intraductal mucinous tumors occurring simultaneously in the liver and pancreas

A case of simultaneous intraductal mucinous tumors of the liver and pancreas in a 67-year-old man is described. Abdominal ultrasonography and computed tomography (CT) revealed the presence of cystic lesions with intraluminal septae both in the caudate lobe of the liver and in the uncinate process of the pancreas; these cystic lesions communicated with the hepatic duct and pancreatic duct, respectively. Mucin retention was observed in the cysts, and cholestasis was induced by mucin secretion into the common bile duct. The lesions were resected by left hepatic lobectomy with caudate lobectomy, and segmental pancreatectomy. Both lesions were multilocular cystic tumors with no papillary projections or focal mass effect in their walls. Histologically, both cystic lesions were a mixture of hyperplasia and adenoma lined by low papillary columnar epithelium. There were no cellular or histological features to suggest malignant change. The fibrous intratumor interstitium lacked any mesenchymal or ovarian-like stroma. The hepatic lesion was considered to be of a similar nature to intraductal papillary mucinous tumor (IPMT) of the pancreas. However, the two lesions occurred simultaneously in the liver and pancreas. This case is of interest in regard to the diagnosis and management of mucinous hepatopancreatobiliary lesions. Received: March 16, 2001 / Accepted: September 14, 2001     

Differential diagnosis of small hepatocellular carcinoma and borderline lesions and therapeutic strategy

BACKGROUND/AIMS: To investigate imaging characteristics and surgical results of adenomatous hyperplasia and early-stage hepatocellular carcinoma. METHODOLOGY: A retrospective study set in the First Department of Surgery, University of Tokushima, Japan. From 1994 to 1997, 33 patients with 55 small hepatocellular carcinomas (< or = 3 cm) and 10 borderline lesions (3 adenomatous hyperplasia, 5 atypical adenomatous hyperplasia, 2 atypical adenomatous hyperplasia with focal malignancy) were enrolled for this study. The detectability of these lesions on imaging was evaluated. Cumulative survival and disease-free survival rates were also calculated. RESULTS: Twenty-eight patients were incidentally diagnosed on ultrasonography during follow-up study for chronic disease. In the conventional studies, detection rates of ultrasonography, computed tomography and angiography for small hepatocellular carcinomas and borderline lesions were 76% 80%, 33% 10% and 36% 20%, respectively. Magnetic resonance imaging, intraoperative ultrasonography, helical computed tomography and portal angiographic computed tomography showed better results of 67% 20%, 100% 90%, 70% 50% and 74% 56%, respectively. On differential diagnosis, the ratio of echo level in small hepatocellular carcinomas was significantly higher than that in borderline lesions. The 3-year and 5-year survival rates for all patients were 61% and 41%, while disease-free survival rates at the corresponding times were 15% and 7%, respectively. A total of 25 patients (76%) developed intrahepatic recurrence during a mean follow-up of 33.8 months, although there was no recurrent lesion in 4 adenomatous hyperplasia patients treated with microwave coagulation therapy and ethanol injection intraoperatively. CONCLUSIONS: For tumors larger than 1 cm in diameter, the detection rates with various diagnostic modalities were rather high. However, the differential diagnosis of borderline lesions from small hepatocellular carcinomas could be based on pathologic studies only. Early detection of small hepatic lesions and treatment by methods such as resection or ethanol injection are of critical importance in improving long-term survival.     

Cystic neoplasm of the pancreas: a Japanese multiinstitutional study of intraductal papillary mucinous tumor and mucinous cystic tumor

The Japan Pancreas Society performed a multiinstitutional, retrospective study of 1379 cases of intraductal papillary mucinous tumor (IPMT) and 179 cases of mucinous cystic tumor (MCT) of the pancreas. Clinicopathologic features and postoperative long-term outcomes were investigated. IPMT were most frequently found in men and in the head of the pancreas. In contrast, all patients with MCT were women. Ovarian-type stroma were found in only 42.2% of the MCT cases. Prognostic indicators of malignant IPMT included advanced age, positive symptoms, abundant mucous secretion, presence of large nodules and/or large cysts, remarkable dilatation of the main pancreatic duct, and main duct- or combined-type IPMT. Advanced age, positive symptoms, and presence of large nodules and/or large cysts were predictive of malignant MCT. The 5-year survival rate of IPMT patients was 98%-100% in adenoma to noninvasive carcinoma cases, 89% in minimally invasive carcinoma cases, and 57.7% in invasive carcinoma cases. The 5-year survival rate of MCT patients was 100% in adenoma to minimally invasive carcinoma cases and 37.5% in invasive carcinoma cases. In conclusion, IPMT and MCT show distinct clinicopathologic and prognostic differences. The results from this study may contribute to the diagnosis and treatment of IPMT and MCT.     

Endoscopic diagnosis and staging of mucinous cystic neoplasms and intraductal papillary-mucinous tumors

Background/Purpose. The number of patients with cystic neoplasms of the pancreas as detected using various types of imaging techniques has been steadily increasing. Among the cystic neoplasms, mucinous cystic neoplasms (MCNs) and intraductal papillary-mucinous tumors (IPMTs) were comparatively more frequently encountered. We used imaging techniques to focus on the differential diagnosis of MCNs and IPMTs, and tumor staging.Methods. Fifteen patients with MCNs with ovarian-like stroma and 109 patients with IPMTs were experienced. We examined the image findings for the differential diagnosis and stage diagnosis of these two types of cystic neoplasms.Results. Endoscopic ultrasonography could reveal detailed images of internal structure and was effective for the diagnosis of MCNs. Other endoscopic imaging modalities could not give specific findings for MCNs. Endoscopic retrograde cholangiopancreatography (ERCP; including duodenoscopic findings and pancreatogram) and pancreatoscopy showed the characteristic and specific findings of IPMTs. Also, endoscopic ultrasonography and intraductal ultrasonography were found to have high sensitivity and diagnostic accuracy for their differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive lesions in IPMTs.Conclusions. Endoscopic imaging techniques are capable of revealing the detailed structure of pancreatic cystic lesions. They are effective for differential diagnosis, for assessing the degree of malignancy, and for deciding upon an appropriate treatment in patients with IPMTs.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)     

Endoscopic ultrasonic diagnosis and cancer of the esophagus. Results of a prospective comparative study with x-ray computed tomography in 51 surgically treated patients

To investigate whether endoscopic ultrasonography could improve the preoperative staging of esophageal carcinoma we prospectively studied 56 tumors in 51 patients between March 1987 an March 1988. The results for assessing local and regional extension and preoperative staging were compared with those of computed tomography, surgery, and pathological findings. When the procedure was complete (n = 25) the accuracy of parietal spread assessment was 85.7 percent; sensitivity for nodal involvement was 83.3 percent versus 50 percent for computed tomography with an accuracy of 97.6 percent versus 96.4 percent; the discrimination between superficial and advanced cancer was 100 percent; the accuracy for preoperative staging using the Japanese classification was 84 percent. When the procedure was not complete (stenosis), endoscopic ultrasonography was complementary to computed tomography: local invasion of anatomical structures (n = 16) was better assessed by combined endoscopic ultrasonography and computed tomography (n = 11) than by endoscopic ultrasonography (n = 8) or computed tomography (n = 6) alone. We conclude that endoscopic ultrasonography is the best procedure for staging esophageal carcinoma without stenosis; further miniaturization of the transducer is necessary to improve results in the case of narrow stenosis.     

Atypical ductal hyperplasia of the pancreas associated with a stricture of the main pancreatic duct

Atypical ductal hyperplasia of the pancreas is thought to be a precancerous lesion. We report a case of atypical ductal hyperplasia associated with a stricture of the main pancreatic duct. A 70-year-old man was admitted to our hospital because of abdominal pain with an elevated serum pancreatic isoamylase level. Endoscopic retrograde cholangiopancreatography disclosed a stricture of the main pancreatic duct in the body of the pancreas. Cytological evaluation of endoscopic brushings suggested adenocarcinoma. Distal pancreatec-tomy was performed. Microscopic examination of the stenotic pancreatic duct showed a hyperplastic epithelium without atypia. Atypical hyperplasia, however, was found in the distal portion of the main pancreatic duct in close proximity to the stricture. Atypical hyperplasia extended along the main pancreatic duct into the ductal branches of the pancreatic tail. In contrast to the vast majority of patients with atypical hyperplasia, the atypical hyperplasia seen in the present patient had no histological features suggestive of intraductal extension of the invasive carcinoma or intraductal papillary-mucinous tumor, thus representing a sporadic precancerous lesion, and it may have been equivalent to carcinoma in situ. Pancreatic duct stricture and the resultant stasis of the pancreatic juice may have promoted the atypical changes in the ductal cells upstream of the stricture. Received: August 20, 2001 / Accepted: February 8, 2002 Reprint requests to: M. Kogire Editorial on page 311     

Preoperative staging of periampullar cancer with US, CT, EUS and CA 19-9

BACKGROUND/AIMS: Several diagnostic methods are available for preoperative staging of periampullary cancers. It happens that on the basis of preoperative findings the patient is prepared for radical surgery, but during the operation the lesion turns out to be unresectable. METHODOLOGY: We studied 43 patients operated on for periampullary cancer. Preoperatively, all patients were evaluated by ultrasonography, computed tomography, endoscopic ultrasonography and the level of carbohydrate antigen 19-9 was assessed. Statistical parameters were calculated and compared. RESULTS: Endoscopic ultrasonography has specificity of 70.8% and positive predictive value regarding tumor resectability 55.8%. Computed tomography has a specificity of 45.8% and carbohydrate antigen 19-9 of 66.7%. Positive predictive value for computed tomography and carbohydrate antigen 19-9 is 40.6% and 52.6%, respectively. Ultrasonography is the least accurate method with specificity of 12.5% and positive predictive value 29.7%. A combined use of different diagnostic methods has higher positive predictive value, highest (65.1%) being found for the combination of endoscopic ultrasonography and carbohydrate antigen 19-9. Statistical tests showed statistically significant differences between diagnostic methods. CONCLUSIONS: Among the diagnostic methods studied, endoscopic ultrasonography showed the highest accuracy in predicting tumor resectability. The use of either endoscopic ultrasonography and carbohydrate antigen 19-9 or computed tomography and carbohydrate antigen 19-9 is accurate enough for assessing tumor resectability.     

Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography (CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm (BD-IPMN).METHODS: A total of 50 patients diagnosed with BD-IPMN by computed tomography (CT) and endoscopic ultrasonography (EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules (MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis.RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS (median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BD-IPMN to 93%.CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.     

MUC1 overexpression is the most reliable marker of invasive carcinoma in intraductal papillary-mucinous tumor (IPMT)

BACKGROUND/AIMS: To clarify the development of pancreatic cancer we performed immunohistochemical analysis of the presence of the major apomucin and cell-cycle regulatory proteins using the tissues of IPMT and ductal adenocarcinoma (DC) of the pancreas. METHODOLOGY: Formalin-fixed and paraffin-embedded tissues of 24 IPMT and 21 DC cases were subjected to immunohistochemical staining for MUC1, MUC2, p16, p53 and DPC4. According to the WHO classification, there were 10 intraductal papillary-mucinous adenomas (IPMA); 3 borderline intraductal papillary-mucinous neoplasms (IPMB); 4 intraductal papillary-mucinous carcinomas (IPMC), non-invasive type (nIPMC); 4 IPMCs with invasive muci nous carcinoma (IPMC/muc); and 3 IPMCs with invasive tubular adenocarcinoma (IPMC/tub). RESULTS: MUC1 expression was seen in 6 of 7 invasive IPMCs (86%) and in all DCs (100%). MUC2 was only seen in non-invasive IPMT and in a part of IPMC/muc. p53 nuclear staining was positive only in 3 of 7 invasive IPMCs (43%) and 9 of 21 DCs (43%). DPC4 nuclear expression was positive in almost all cases of non-invasive IPMT, but negative or reduced in 4 of 7 invasive IPMCs (57%), and 14 of 21 DCs (67%). CONCLUSIONS: MUC1 overexpression is considered to be the most sensitive and specific marker of invasive carcinoma, followed by DPC4 and p53 with less sensitivity.     

Endobiliary biopsy

The differential diagnosis between benign and malignant biliary strictures is challenging and requires a multidisciplinary approach with the use of serum biomarkers, imaging techniques, and several modalities of endoscopic or percutaneous tissue sampling. The diagnosis of biliary strictures consists of laboratory markers, and invasive and non-invasive imaging examinations such as computed tomography (CT), contrast-enhanced magnetic resonance cholangiopancreatography, and endoscopic ultrasonography (EUS). Nevertheless, invasive imaging modalities combined with tissue sampling are usually required to confirm the diagnosis of suspected malignant biliary strictures, while pathological diagnosis is mandatory to decide the optimal therapeutic strategy. Although EUS-guided fine-needle aspiration biopsy is currently the standard procedure for tissue sampling of solid pancreatic mass lesions, its diagnostic value in intraductal infiltrating type of cholangiocarcinoma remains limited. Moreover, the “endobiliary approach” using novel slim biopsy forceps, transpapillary and percutaneous cholangioscopy, and intraductal ultrasound-guided biopsy, is gaining ground on traditional endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography endobiliary forceps biopsy. This review focuses on the available endobiliary techniques currently used to perform biliary strictures biopsy, comparing the diagnostic performance of endoscopic and percutaneous approaches.     

Differentiating pancreatic cancer from pseudotumorous chronic pancreatitis

The differentiation between pancreatic carcinoma and pseudotumorous pancreatitis continues to be a challenge. Several diagnostic imaging and endoscopic modalities can assist in making the differentiation, but the accuracy of each method varies. Radiologic imaging techniques include transabdominal ultrasound, computed tomography, magnetic resonance imaging, magnetic resonance cholangiopancreatography, and positron emission tomography. Endoscopic techniques include endoscopic ultrasonography, intraductal ultrasonography, and endoscopic retrograde cholangiopancreatography with brush cytology of pancreatobiliary strictures, endoscopic forceps biopsy, and analysis of pancreatic juices for malignant cells. Tumor markers appear to be promising, but further studies are needed to define the role of these markers.