Fluorescent in situ hybridisation as diagnostic adjunct in pancreatobiliary cytology: the auckland experience

Abstract

<h3>Aims</h3> To evaluate the clinical, endoscopic retrograde cholangio-pancreatography (ERCP) and cytological features of cases where fluorescent <i>in situ</i> hybridisation (FISH) was used as diagnostic adjunct in the cytological detection of pancreatobiliary malignancy. Cytology and FISH will be correlated with histology. <h3>Methods</h3> The cytology database was searched for all pancreatobi-liary cytology cases where FISH was requested as an ancillary test. The clinical history, ERCP findings, cytological features, FISH findings and histological diagnosis were reviewed. <h3>Results</h3> FISH was requested in a total of 30 biliary brushing cytology cases since September 2010. Median age was 64.5 years and three (10%) patients had a history of primary sclerosing chol-angitis. Fifteen (50%) cases were atypical or suspicious for malignancy on cytology. Of these, five (33.3%) cases were positive for malignancy on FISH. All 10 (100%) of the cases with a histologi-cal diagnosis correlated with FISH results. FISH revealed homozy-gous deletion of 9p21 in one biopsy negative case. <h3>Conclusions</h3> FISH is useful in the diagnosis of pancreatobiliary malignancy. It should be used in conjunction with patient age, primary sclerosing cholangitis status and cytology findings. Homo-zygous 9p21 deletion in the absence of other FISH abnormalities should be interpreted with caution.