Background & Objective: Biliary system lesions including ampulla of vater are considered as important diseases of gasterointestinal system because of difficult availability in endoscopy, dangers of biopsy and diagnosis in advanced stages.Regarding previous studies about the role and sensitivity of brushing cytology in diagnosis of lesions in this area and lack of serious complications in this procedure, we decided to evaluate the sensitivity and specificity of this method.

Method: Observing 45 patients with biliary system lesions who referred to gasterointestinal research center of Shariati hospital for ERCP, cytologic specimens were provided and biopsies were taken, if possible. Then the patients were followed up periodically and cytologic results were compared with biopsies or follow-ups.

Results: All specimens with positive biopsy for malignancy exhibited positive cytologic results and all except one with negative biopsy exhibited negative cytologic results. There was only one case of negative biopsy with positive cytologic result reported. Therefore, the study revealed a significant association between cytology and biopsy results. (df=1, chi square, p= 0.04). Compared to biopsy cytology had relatively good sensitivity and specificity which corresponded to the findings of other studies(sen: 100%, spec: 80%, PPV=Positive Predictive Value: 88.8%, NPV=Negative Predictive Value: 100%). Adding positive results of follow-ups to biopsies and comparing them with cytology illustrated acceptable sensitivity and specificity of this method(sen: 73%, spec: 83.5%, PPV:91.6%, NPV:50%).

Conclusion: The results of this study indicate that brushing cytology is a suitable method to diagnose periampullary lesions in comparison with biopsy or follow-up(P<0.05).