Alastair R.S. Deery

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.

Value of exfoliative cytology for investigating bile duct strictures.

The cause of a biliary tract stricture may be difficult to determine radiologically. Exfoliative biliary cytology was evaluated in 62 patients (median age 65 years, range 30-94) with biliary tract strictures presenting to the Hepatobiliary Unit between January 1984 and December 1989. Bile samples were taken during endoscopic retrograde cholangiopancreatography (ERCP) in 42 patients, percutaneous cholangiography in 14, and both in six. The site of stricturing was upper third of the bile duct in 43% (n = 27), middle third in 10% (n = six), and lower third in 47% (n = 29). Of the 47 patients with radiological appearances of a malignant stricture, 22 (47%) had histological confirmation by biopsy either under computed tomography guidance, at endoscopy, at operation, or at necropsy. Fourteen of the 47 patients had positive cytology (30%). In seven patients cytology alone established the presence of malignancy (15%) and in the other seven positive cytology was confirmed by histology. The addition of cytology to tissue biopsy therefore allowed malignancy to be confirmed in 29 of the 47 patients (62%). None of the 15 patients subsequently shown to have benign disease had positive cytology. Sensitivity of the technique was 30% and specificity 100%. Samples for exfoliative cytology are simple to obtain, the results are highly specific and should be a routine part of the investigation of biliary strictures.