Prospective evaluation of advanced molecular markers and imaging techniques in patients with indeterminate bile duct strictures

BACKGROUND AND  AIMS: Standard techniques for evaluating bile duct strictures have poor sensitivity for detection of malignancy. Newer imaging modalities, such as intraductal ultrasound (IDUS), and advanced cytologic techniques, such as digital image analysis (DIA) and fluorescence in situ hybridization (FISH), identify chromosomal abnormalities, and may improve sensitivity while maintaining high specificity. Our aim was to prospectively evaluate the accuracy of these techniques in patients with indeterminate biliary strictures.
METHODS: Cholangiography, routine cytology (RC), intraductal biopsy, DIA, FISH, and IDUS were performed in 86 patients with indeterminate biliary strictures. Patients were stratified based on the presence or absence of primary sclerosing cholangitis (PSC).
RESULTS: RC provided low sensitivity (7–33%) but high specificity (95–100%) for PSC and non-PSC patients. The composite DIA/FISH results (when considering trisomy-7 [Tri-7] as a marker of benign disease) yielded a 100% specificity and increased sensitivity one- to fivefold in PSC patients versus RC, and two- to fivefold in patients without PSC, depending on how suspicious cytology results were interpreted. For the most difficult-to-manage patients with negative cytology and histology who were later proven to have malignancy (N = 21), DIA, FISH, composite DIA/FISH, and IDUS were able to predict malignant diagnoses in 14%, 62%, 67%, and 86%, respectively.
CONCLUSIONS: DIA, FISH, and IDUS enhance the accuracy of standard techniques in evaluation of indeterminate bile duct strictures, allowing diagnosis of malignancy in a substantial number of patients with false-negative cytology and histology. These findings support the routine use of these newer diagnostic modalities in patients with indeterminate biliary strictures.     

The combination of stricture dilation, endoscopic needle aspiration, and biliary brushings significantly improves diagnostic yield from malignant bile duct strictures.

BACKGROUND: Brush cytology, routinely performed at ERCP to assess malignant-appearing biliary strictures, is limited by relatively low sensitivity and negative predictive value. This study assessed whether the combination of stricture dilation, endoscopic needle aspiration, and biliary brushing improves diagnostic yield. METHODS: In a prospective nonrandomized study, 46 consecutive patients were evaluated with malignant-appearing biliary strictures at ERCP. Twenty-four patients (Group A) underwent standard brush cytology alone and 22 patients (Group B) underwent stricture dilatation to 10F, endoscopic needle aspiration, and subsequent biliary brushing by using the Howell biliary system. The diagnostic yields for both techniques were compared. RESULTS: Of the 46 patients, 34 had proven malignant strictures (14 Group A, 20 Group B). Compared with brushing alone, the combination of stricture dilatation, endoscopic needle aspiration, and subsequent biliary brushing significantly increased both the sensitivity (57% vs. 85%, p < 0.02) and specificity (80% vs. 100%, p < 0.02) of cytology with positive brushings in all patients with pancreatic or gallbladder carcinoma. CONCLUSIONS: The combination of stricture dilation, endoscopic needle aspiration, and biliary brushing significantly improves diagnostic yield for malignant bile duct strictures and may particularly be of benefit for extrinsic strictures caused by pancreatic or gallbladder carcinoma.     

Cytodiagnosis in the management of extrahepatic biliary stricture.

A total of 117 patients presenting with extrahepatic biliary strictures between 1981 and 1989 had 206 cytological examinations of the bile duct or bile (153 non-operative, 53 intraoperative) to establish the presence of malignancy. A final diagnosis of cholangiocarcinoma was made in 88 patients, with 29 patients having benign biliary strictures. The cytological techniques used were fine needle aspiration (n = 102) or brushing (n = 24) of the bile duct, or exfoliative cytology of bile (n = 80). Forty one patients with malignancy had two or more examinations with differing results between samples in 20 cases. The overall sensitivity was 72%. There was only one false positive result, giving a patient predictive value of positive cytology of 98%. Intraoperative cytology was more sensitive than non-operative examination (80% v 42%). Overall, the sensitivity of fine needle aspiration (67%) was greater than that of brush cytology (40%) or exfoliative cytology (30%). No complications were encountered. Cytodiagnosis of extrahepatic biliary strictures is a safe procedure which is not technically demanding, and as it has a high sensitivity and predictive value for positive cytology, cytological confirmation of malignancy should be sought in all clinically and radiologically suspicious cases.     

经内镜细胞刷检查对胆管恶性狭窄性病变的诊断价值

目的 探讨经内镜细胞刷检查对胆管恶性狭窄性病变的诊断价值,分析影响诊断的因素.方法 对ERCP检查发现可疑胆管恶性狭窄的144例患者行胆管细胞刷检查.2004年-2006年在胆管内来回拉刷10次 2007年-2009年在狭窄部位来回拉刷20次,并重复操作2次.专业病理医师固定阅片,对照术后病理诊断和（或）临床最终诊断,分析细胞刷检查诊断胆管狭窄病变的作用.结果 最终诊断96例为胆管恶性狭窄,48例良性狭窄.恶性狭窄患者中78例细胞刷检查阳性（敏感度81.3%）,18例阴性 良性狭窄患者细胞刷检查均为阴性（特异度100.0%） 总体准确率87.5%.2007年-2009年间恶性狭窄性病变细胞刷检出率为87.7%（50/57）,2004年-2006年间检出率仅为71.8%（28/39）,差异有统计学意义（P＜0.05）.细胞刷检查阳性率与肿瘤来源及狭窄部位无明显关系.术后发生4例轻度胰腺炎、3例胆管炎、2例胆管出血,无严重并发症发生.结论 胆管细胞刷检查对恶性胆管狭窄病变具有较高的特异度和敏感度,于狭窄部位反复拉刷和重复操作有助于提高细胞刷检阳性率.     

Brush cytology evaluation of lesions encountered during ERCP

Malignant obstruction of the pancreaticobiliary system is a frequent indication for ERCP. Twenty-five patients with abnormalities suggestive of malignancy were encountered during ERCP at our institution and brush cytology was obtained. Positive cytology specimens were collected in 12 of 20 (60%) cases of malignancy causing biliary obstruction. Using a recently developed cytology brush for the biliary tree, detection of malignancy in strictures of the bile duct had a sensitivity of 50% and a specificity of 100%. Both cases of cholangiocarcinoma were diagnosed with cytology, as were 5 of 10 cases of pancreatic cancer. It is concluded that brush cytology is a diagnostically reliable, highly specific technique for malignant lesions encountered at ERCP. In experienced hands, a positive cytologic result may obviate the need for additional invasive diagnostic studies.     

A comparison of cytology and fluorescence in situ hybridization for the detection of lung cancer in bronchoscopic specimens

STUDY OBJECTIVES: To determine the relative sensitivity and specificity of cytology and fluorescence in situ hybridization (FISH) for the detection of lung cancer in bronchoscopically obtained specimens. DESIGN: Cytology and FISH were performed on brushing and washing specimens obtained from patients undergoing bronchoscopy for suspected lung cancer. FISH utilized the LAVysion probe set (Abbott Molecular; Des Plaines, IL), which contains locus-specific probes to 5p15, 7p12 (EGFR), 8q24 (C-MYC), and a centromeric probe to chromosome 6. SETTING: Single-center, academic, tertiary medical center. PARTICIPANTS: One hundred thirty-seven patients referred for bronchoscopy for suspicion of lung cancer. INTERVENTIONS: Cytology and FISH were performed on bronchoscopic brushings and washings. MEASUREMENTS AND RESULTS: One hundred thirty-seven patients undergoing bronchoscopy had pathology, FISH, and cytology results. FISH and cytology were performed on 123 washing and 78 brushing specimens. Sensitivities of FISH and cytology were 71% and 51% (p = 0.007), respectively, for brushing specimens, and 49% and 44% (p = 0.541) for washing specimens. When FISH and cytology results were combined, sensitivities were 75% and 61%, respectively, for brushing and washing specimens, which was significantly better (p < 0.001) than cytology alone. Specificities of FISH and cytology for patients with negative findings at the time of initial bronchoscopy were 83% and 100% (p = 0.125), respectively, for brushing specimens, and 95% and 100% (p = 0.500) for washing specimens. CONCLUSIONS: These findings show that FISH is significantly more sensitive than conventional cytology for detecting lung cancer in bronchial brushing specimens; when combined with cytology, FISH can improve the diagnostic sensitivity of detecting malignancy in bronchial brushing and washing specimens.     

Advanced cytologic techniques for the detection of malignant pancreatobiliary strictures

BACKGROUND & AIMS: Two advanced cytologic techniques for detecting aneuploidy-digital image analysis (DIA) and fluorescence in situ hybridization (FISH)-have recently been developed to help identify malignant pancreatobiliary strictures. The aim of this study was to assess the clinical utility of cytology, DIA, and FISH for the identification of malignant pancreatobiliary strictures. METHODS: Brush cytologic specimens from 233 consecutive patients undergoing endoscopic retrograde cholangiopancreatography for pancreatobiliary strictures were examined by all 3 (cytology, DIA, and FISH) techniques. Strictures were stratified as proximal (n = 33) or distal (n = 114) based on whether they occurred above or below the cystic duct, respectively. Strictures in patients with primary sclerosing cholangitis (n = 86) were analyzed separately. RESULTS: Despite the stratification, the performances of the tests were similar. Conventional cytology has a low sensitivity (4%-20%) but 100% specificity. Because of the high specificity for cytology, we assessed the performance of the other tests when conventional cytology was negative. In this clinical context, FISH had an increased sensitivity (35%-60%) when assessing for chromosomal gains (polysomy) while preserving the specificity of cytology. The sensitivity and specificity of DIA was intermediate as compared with routine cytology and FISH but was additive to FISH values demonstrating only trisomy of chromosome 7 or chromosome 3. CONCLUSIONS: These findings suggest that FISH and DIA increase the sensitivity for the diagnosis of malignant pancreatobiliary tract strictures over that obtained by conventional cytology while maintaining an acceptable specificity.     

A prospective evaluation of cytology from biliary strictures.

BACKGROUND: Bile duct strictures may be benign or malignant. A definite diagnosis is desirable to advise patients of their prognosis and to identify any amenable to curative surgery. AIMS: To compare different methods of cytology sampling from biliary strictures and evaluate the use of cytology in this context. PATIENTS AND METHODS: In a prospective study 54 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) had cytology samples obtained as follows: (1) biliary stricture brushings, (2) from the screw thread of a "Soehendra stent retriever" inserted through the stricture, (3) from the proximal end of a blocked biliary stent, and (4) cellular material spun down from a 20 ml specimen of bile. Examination of slides and rinsings was performed by an expert cytologist who graded them for the adequacy of the sample and for evidence of malignancy. RESULTS: Prolonged follow up disclosed malignancy in 52 of the 54 cases, the other two being chronic pancreatitis. Bile samples provided adequate cytology samples in 44%, the Soehendra stent retriever in 70%, retrieved stents in 84%, and cytology brush sampling in 96%. Overall, 28 malignancies were detected by cytology, including 14 of 28 pancreatic carcinomas and 12 of 16 cholangiocarcinomas. Twenty two of the malignancies were detected by brush sampling and the other methods added a total of another six cases. CONCLUSIONS: Cytology sampling is best done by brushing the biliary stricture. Cytology sampling can confirm the diagnosis in 75% of cholangiocarcinomas and 50% of pancreatic carcinomas. The techniques involved are simple to perform and should be routine clinical practice whenever potentially malignant biliary strictures are encountered at ERCP.     

Usefulness of transpapillary bile duct brushing cytology and forceps biopsy for improved diagnosis in patients with biliary strictures

BACKGROUND AND AIM: Transpapillary bile duct brushing cytology and/or forceps biopsy was performed in the presence of an indwelling guidewire in patients with biliary stricture, and the treatment time, overall diagnosis rate, diagnosis rate of each disease, complications, and influences on subsequent biliary drainage were investigated. METHODS: After endoscopic retrograde cholangiography, brushing cytology was performed, followed by forceps biopsy. In patients with obstructive jaundice, endoscopic biliary drainage (EBD) was subsequently performed. To investigate the influences of bile duct brushing cytology and forceps biopsy on EBD, patients who underwent subsequent EBD by plastic stent were compared with patients who underwent EBD alone. RESULTS: The samples for cytology were collected successfully in all cases, and the sensitivity for malignancy/benignity, specificity, and accuracy were 71.6%, 100%, and 75.0%, respectively. The biopsy sampling was successful in 51 patients, and samples applicable to the evaluation were collected in all 51 patients. The sensitivity for malignancy/benignity, specificity, and accuracy were 65.2%, 100%, and 68.6%, respectively. Combination of the two procedures increased the sensitivity and accuracy to 73.5% and 76.6%, respectively. The time required for cytology and biopsy was 11.7 min, which is relatively short. Cytology and biopsy did not affect drainage. Regarding accidents, bile duct perforation occurred during biopsy in one patient (1.9%), but was rapidly improved by endoscopic biliary drainage. CONCLUSIONS: Transpapillary brushing cytology and forceps biopsy could be performed in a short time. The diagnosis rate was high, and the incidence of complication was low, having no influence on subsequent biliary drainage.     

Brush cytology of ductal strictures during ERCP

BACKGROUND: Previous reports on endoscopic retrograde brush cytology (ERBC) of bile ducts and of the main pancreatic duct have reached widely varying sensitivity levels of 33 up to 85%. AIMS: To report our experience with ERBC in a series of biliary strictures (n = 98) and pancreatic duct strictures (n = 8). For the purpose of our study, that was mainly directed to the value of the cytologic examination as such, only those specimens that were considered satisfactory for cytological interpretation were studied. PATIENTS: From October 1988 until August 1994, 154 cytologic brushings were performed at ERCP in 132 patients. In 132 brushings obtained from 115 patients (86%), cell yield was satisfactory for cytologic interpretation. Nine patients lacked adequate follow-up. Hence, 123 brushings from 106 patients were included in this study. A final diagnosis of malignancy was obtained in 62 patients. METHODS: Cytological changes were described as 'benign', 'columnar cell intraepithelial neoplasia', 'inconclusive' by the presence of atypical cells, or 'malignant'. RESULTS: For a positive diagnosis of the malignant nature of a stenosis, ERBC had an overall sensitivity of 63% with a specificity of 96%. One false positive result was obtained in a patient with a biliary infection by Fasciola Hepatica. Sensitivity was highest in malignant ampullary strictures (91%). Sensitivity was 60% for cholangiocarcinomas, and 65% for pancreatic cancer. The finding of 'columnar cell intra-epithelial neoplasia' in the ampullary region led to a Whipple resection and diagnosis of invasive carcinoma in one patient. Atypical cells were found in 4 brush specimens: in three of these 4 cases, a malignant lesion proved to be present. CONCLUSIONS: Brush cytology is a simple technique with a high specificity and should be performed in biliary and pancreatic duct strictures of unknown etiology. Categorizing the smears according to cytomorphology may improve diagnostic accuracy.     

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.)     

Role of fluorescence in situ hybridization in diagnosing cholangiocarcinoma in indeterminate biliary strictures

Background and Aim

Brush cytology, the conventional method to diagnose cholangiocarcinoma, has been plagued by low diagnostic sensitivity and false‐negative results. This paper aims to study the clinical utility of fluorescence in situ hybridization (FISH) in enhancing identification of malignant biliary strictures.

Methods

Brush cytologic specimens collected from endoscopic retrograde cholangiopancreatography for biliary strictures in a tertiary hospital in Singapore from March 2013 to July 2015 were examined by FISH technique using UroVysion probe set in this study.

Results

Thirty patients were chosen with five patients having multiple FISH performed due to indeterminate results. The diagnoses for biliary strictures were 13 (43.3%) cholangiocarcinomas, seven (23.3%) pancreatic cancers, seven (23.3%) benign biliary strictures, and three (10%) primary sclerosing cholangitis. Conventional brush cytology had sensitivity of 53.8% with specificity of 82.4%. FISH had sensitivity of 30.8% with specificity of 100%. When FISH results were interpreted in cases with negative or atypical brush cytology, two patients had positive FISH results and cholangiocarcinomas. Based on this pilot study, FISH increased sensitivity of brush cytology in detection of cholangiocarcinoma from 53.8% to 69.2% while preserving specificity of 82.4%.

Conclusion

Compared with conventional cytology with low sensitivity, FISH may help to increase sensitivity on top of brush cytology while maintaining high specificity.     

Influence of stricture dilation and repeat brushing on the cancer detection rate of brush cytology in the evaluation of malignant biliary obstruction

BACKGROUND: The sensitivity for cancer detection of brush cytology at ERCP is relatively low. Manipulation of the stricture and repeated tissue sampling may increase the yield. This study compared the cancer detection rate of brush cytology before and after biliary stricture dilation. METHODS: In patients with a biliary stricture at ERCP of suspected malignant origin, the stricture was sampled with a cytology brush and then dilated with either a graduated dilating catheter or a dilating balloon (4-8 mm). Brushing was then repeated in all patients. Specimens were interpreted as normal, atypical (benign), highly atypical (suspicious for cancer), and malignant. Final diagnoses were based on cytology plus surgery, EUS, percutaneous biopsy, autopsy, or clinical follow-up. RESULTS: A total of 139 patients with suspected malignant obstructive jaundice underwent 143 ERCPs (116 ultimately found to have malignant obstruction, and 27 benign disease). Dilation was performed with a catheter in 68 cases, balloon in 73, and both in 2. Brush cytology had a sensitivity of 34.5% (40/116) before dilation and 31% (36/116) after dilation (p = NS). However, sensitivity with predilation and postdilation brushing specimens combined was 44% (51/116), which was higher than that for either the predilation or postdilation brush cytology (p = 0.001). Cancer detection rates were 34.7% (17/49) after dilation with the catheter and 27.7% (18/65) after balloon dilation (p = NS). CONCLUSIONS: Stricture dilation does not improve the sensitivity of brush cytology for the detection of cancer, which remains relatively low. However, repeat brushing increases the diagnostic yield and should be performed when sampling biliary strictures with a cytology brush at ERCP.     

A prospective controlled study comparing brush and bile exfoliative cytology for diagnosing bile duct strictures.

Imaging of biliary strictures may suggest malignancy but cytology can provide a tissue diagnosis. The aim of this study is to compare the diagnostic value of brush cytology and bile cytology. Thirty two patients (20 males, 12 females, median age 66 years, range 31-84) with biliary strictures at endoscopic retrograde cholangio pancreatography (24) or percutaneous transhepatic cholangiography (8) had bile cytology and brush cytology. Brushings were taken using a modified Geenan cytology brush (6 Fr gauge, Wilson Cook) passed alongside a guide wire placed through the stricture. Bile was aspirated after insertion of an internal/external catheter or an endoprosthesis. Bile and brushings were examined by one experienced cytologist (AD) and was reported as positive or negative for malignant cells. Twenty nine patients had malignant strictures. Sixteen were confirmed by histology and 13 had malignancy suggested by clinical follow up. Three patients had resection of histologically benign strictures. The overall sensitivity of brush cytology (17 of 29 positive, 59%) was significantly greater than bile cytology (seven of 29 positive, 24%) (p < 0.01) as was the diagnostic accuracy (63 v 31%, p < 0.01). None of the patients had positive bile cytology with negative brush cytology. There were no procedure related complications and the average sampling time once the guide wire had been inserted was less than five minutes. It is concluded that brush cytology is more sensitive than bile cytology and with the technique described is safe and rapid.     

Prospective study of biliary strictures to determine the predictors of malignancy.

BACKGROUND: There have been few prospective studies regarding the investigation of biliary strictures, principally because of rapid technological change. The present study was designed to determine the sensitivity of various imaging studies for the detection of biliary strictures. Serum biochemistry and imaging studies were evaluated for their role in distinguishing benign from malignant strictures. METHODS: Thirty-one patients with suspected noncalculus biliary obstruction were enrolled consecutively in the study. A complete biochemical profile, ultrasound, Disida scan and cholangiogram (endoscopic retrograde cholangiopancreatography [ERCP] or percutaneous cholangiogram) were obtained at study entry. Stricture etiology was determined based on cytology, biopsy and/or clinical follow-up at one year. RESULTS: Twenty-nine of 31 patients had biliary strictures, of which 15 were malignant. The mean age of the malignant cohort was 73.9 years versus 53.9 years in the benign cohort (P<0.001). Statistically significant differences between the malignant and benign groups, respectively, were as follows: alanine transaminase 235.2 versus 66.9 U/L (P=0.004), aspartate transaminase 189.8 versus 84.5 U/L (P=0.011), alkaline phosphatase 840.2 versus 361.1 U/L (P=0.002), bilirubin 317.8 versus 22.1 micromol/L (P<0. 001) and bile acids 242.5 versus 73.2 micromol/L (P=0.001). Threshold analysis using receiver operative characteristic (ROC) curves demonstrated that a bilirubin level of 75 micromol/L was most predictive of malignant strictures. Intrahepatic duct dilation was present in 93% of malignant strictures versus 36% of benign strictures (P=0.002). Common hepatic duct dilation was less discriminatory (malignant 13.5 versus benign 9.6 mm; P=0.11). Ultrasound was highly sensitive (93%) in the detection of the primary tumour in the bile duct or pancreas, or in the visualization of nodal or liver metastases. In benign disease, ultrasound failed to detect evidence of intrahepatic or extrahepatic biliary dilation in most cases. Disida scans were not able to distinguish between malignant or benign strictures and could not accurately localize the level of obstruction. The sensitivity of Disida scan for the diagnosis of obstruction was 50%. Cholangiographic characterization of strictures revealed an equal distribution of smooth (eight of 13) and irregular (five of 13) strictures in the malignant group. Ten of 13 benign strictures were characterized as smooth. Malignant strictures were significantly longer than benign ones - 30.3 versus 9.2 mm (P=0.001). Threshold analysis using ROC curves showed that strictures greater than or equal to 14 mm were predictive of malignancy (sensitivity 78%, specificity 75%, log odds ratio 11.23). CONCLUSIONS: A serum bilirubin level of 75 micromol/L or higher, or a stricture length of greater than 14 mm was highly predictive of malignancy in patients with a biliary stricture. Ultrasound was useful in predicting malignant strictures by detecting either intrahepatic duct dilation or by visualizing the tumour (primary or metastases). Strictures with a 'benign' cholangiographic appearance are frequently malignant. Disida scan did not add additional information. ERCP is necessary to diagnose benign strictures, which tend to be less extensive at presentation.     

Use of microsatellite marker loss of heterozygosity in accurate diagnosis of pancreaticobiliary malignancy from brush cytology samples

BACKGROUND: Brush cytology of biliary strictures to diagnose pancreaticobiliary malignancy suffers from poor sensitivity. AIM: To improve the diagnostic yield of pancreaticobiliary brush cytology through analysis of tumour suppressor gene linked microsatellite marker loss of heterozygosity (LOH) and k-ras codon 12 mutation detection. METHODS: Twenty six patients with biliary strictures underwent endoscopic retrograde cholangiography with brush cytology. A panel of 12 polymorphic microsatellite markers linked to six tumour suppressor genes was developed. Genomic DNA from cell clusters acquired from brush cytology specimens and microdissected surgical malignant and normal tissue underwent polymerase chain amplification reaction (PCR). PCR products were compared for LOH and k-ras codon 12 mutations. RESULTS: Seventeen patients were confirmed to have pancreaticobiliary adenocarcinoma. Nine patients had benign strictures (eight proven surgically, one by follow up). Cytomorphological interpretation was positive for malignancy (n = 8), indeterminate (n = 10), and negative for malignancy (n = 8). Selected malignant appearing cytological cell clusters and microdissected histological samples from cancer showed abundant LOH characteristic of malignancy while brushings from nine cases without cancer carried no LOH (p<0.001). LOH and k-ras mutations profile of the cytological specimens was almost always concordant with the tissue samples. Presence of k-ras mutation predicted malignancy of pancreatic origin (p<0.001). CONCLUSION: LOH and k-ras codon 12 mutation analysis of PCR amplified DNA from biliary brush cytology discriminates reactive from malignant cells, with 100% sensitivity, specificity, and accuracy. Minor variations in LOH in brushings and in different sites within the same tumour likely reflect intratumoral mutational heterogeneity during clonal expansion of pre- and neoplastic lineages.     

Detection of Ki-ras gene point mutations in bile specimens for the differential diagnosis of malignant and benign biliary strictures

BACKGROUND AND AIM: The present study was undertaken to determine if detection of Ki-ras gene point mutations in bile specimens could differentiate between benign and malignant biliary strictures. PATIENTS: Bile specimens were obtained from 117 patients exhibiting a stricture of the main bile duct, the nature of which was assessed by cholangiography, histology, and follow up. METHODS: DNA from frozen bile specimens was extracted, amplified, and tested for codon 12 point mutations of Ki-ras gene using sequence specific oligonucleotide hybridisation and mutant allele specific amplification. RESULTS: DNA amplification was successful in 110/117 bile specimens (94%). Detection of Ki-ras gene mutations in bile specimens was positive in 24.4% (22/90) of patients with malignant strictures, in 31.4% (22/70) when only primary malignant tumours were considered, and in 4% (1/25) of patients with benign strictures. Of the 49 patients with histological specimens obtained before surgery, the sensitivity of histology, Ki-ras mutation analysis, and combined methods was 59.2%, 28.6%, and 73.5% respectively. CONCLUSIONS: Our study showed that Ki-ras mutations may be detected in about one third of bile specimens from patients with primary tumours invading the main bile duct. Detection of such mutations appears to be specific and may help to differentiate between benign and malignant biliary strictures.     

Endoscopic needle aspiration biopsy at ERCP in the diagnosis of biliary strictures.

We have developed a ball-tipped catheter with a retractable 22-gauge, 7-mm long needle to perform endoscopic needle aspiration (ENA) for cytology and compared this technique to brush cytology of malignant-appearing biliary strictures during ERCP. Of 31 patients, 26 had proven malignant strictures involving the common bile duct and 5 had benign lesions. All 31 patients had ENA and 29 were brushed. Positive ENAs were obtained in 16 of 26 patients (61.5%) and positive brushings in 2 of 24 (8.3%). With the addition of two suspicious ENAs for pancreatic adenocarcinoma, 73% of patients had positive or suspicious cytology for malignancy by combined ENA and brush with a specificity of 100%. Although ENA appeared to be more sensitive in diagnosing cholangiocarcinoma, it proved to be most effective in the diagnosis of pancreatic adenocarcinoma when compared with brush cytology. One patient with cholangiocarcinoma in our series was diagnosed by brush cytology only, with a negative ENA, supporting our recommendation of using both endoscopic brushings and ENA for cytology when evaluating biliary strictures.     

多种内镜检查方法联合应用对胆管狭窄性疾病的诊断价值

目的评估多种内镜检查方法联合应用对胆管狭窄性疾病的诊疗价值。方法回顾性分析36例胆管狭窄性疾病患者的诊断情况。36例患者均进行了超声内镜检查术（EUS）、经内镜逆行胰胆管造影术（ERCP）、胆管内超声检查术（IDUS）,胆道靶向刷检行细胞学涂片、液基薄层细胞学检查,并结合临床资料及组织学病理检查,综合诊断。结果最终诊断胆管恶性病变21例,其中胆管细胞癌9例、十二指肠乳头癌4例、胰腺癌侵犯胆总管4例、肝癌侵犯胆总管4例;胆管良性病变15例,其中胆总管结石9例、肝吸虫感染所致胆管狭窄4例、单纯胆管炎性狭窄1例、外部压迫所致胆管狭窄1例。EUS、ERCP、IDUS及ERCP＋IDUS对胆管狭窄性疾病鉴别诊断的准确率分别为77．8％、88．9％、91．7％、94．4％,ERCP、IDUS及ERCP＋IDUS均明显高于EUS（P均〈0．05）;ERCP＋IDUS对胆管狭窄性疾病鉴别诊断的敏感度、特异度、阳性预测值与阴性预测值分别为95．2％、93．3％、95．2％、93．3％,均高于EUS、ERCP及IDUS单独检查。胆道刷检细胞学、液基薄层细胞学或组织病理学检查,19例诊断为恶性狭窄,17例诊断为良性狭窄,对鉴别胆管狭窄性质诊断的敏感度为90．5％、特异度为100．0％、准确率为94．4％。结论对于胆管狭窄性病变,ERCP＋IDUS可使诊断准确率得到明显提高;联合应用ERCP＋IDUS＋病变胆管的靶向刷检等多种内镜检查方法,诊断准确率更高。     

Clinical significance of bile cytology via an endoscopic nasobiliary drainage tube for pathological diagnosis of malignant biliary strictures

Background/purpose

In patients in whom there is a suspicion of malignant biliary strictures, bile cytology via an endoscopic nasobiliary drainage tube (ENBD cytology) is often performed, in addition to aspirated bile cytology, brush cytology, and forceps biopsy, during the initial endoscopic retrograde cholangiopancreatography (ERCP). We aimed to reveal the significance of ENBD cytology for the pathological diagnosis of malignant biliary strictures.

Methods

We studied 214 patients with malignant biliary strictures. We performed aspirated bile cytology, brush cytology, and forceps biopsy in 93, 130, and 114 patients, respectively. ENBD cytology was performed one or more times in 79 patients. We examined the sensitivity of each sampling method, and analyzed the utility of ENBD cytology.

Results

The sensitivities of each sample acquisition method were as follows: 30% (28/93) for aspirated bile cytology, 48% (62/130) for brush cytology, 41% (47/114) for forceps biopsy, and 24% (19/79) for ENBD cytology. In 19 patients who showed positive ENBD cytology, other methods were performed in 11. Aspirated bile cytology, brush cytology, and forceps biopsy, were performed in 7, 5, and 6 patients, and the results were negative in 3 (43%), 2 (40%), and 1 (17%) patient, respectively. Three patients showed positive results only on ENBD cytology.

Conclusions

Although the sensitivity of ENBD cytology was inferior to that of the other methods used, ENBD cytology may contribute to the improvement of the total diagnostic sensitivity for malignancy.