UroVysion Fluorescent in Situ Hybridization (U-FISH) Remains the Most Sensitive Method for Pancreatobiliary Stricture Malignancy Detection

Abstract Background and Aims Reports on fluorescent in situ hybridization (FISH) of pancreatobiliary strictures have shown a wide range of sensitivities for malignancy detection. Our aim was to determine the sensitivity and specificity at our institution of biliary brushings, forceps biopsies, fine needle aspirations, FISH, and their combinations. Methods The study entailed a retrospective review of all cases with pancreatobiliary stricture specimens at our institution over a 5-year period. The medical record for each case was reviewed to independently confirm the presence or absence of malignancy. Sensitivities and specificities were calculated for each method. Results The cohort consisted of 181 sampling procedures from 154 patients. Of the patients, 39 (25.3%) had primary sclerosing cholangitis (PSC) and 41 (26.6%) had malignancy. Brush cytology sensitivity ranged from 24 to 63%. Forceps biopsy sensitivity ranged from 24 to 49%. FNA sensitivity ranged from 32 to 60%. Brush FISH ranged from 58 to 95%. Specificity was 99% for brush FISH and 100% for all other methods. The one false positive was an isolated FISH result in a case of PSC. Conclusion FISH should be performed since it is more sensitive than all other methods and nearly perfect in specificity outside the context of PSC. In PSC, isolated positive FISH results should be interpreted with caution.