Role of fluorescence in situ hybridization in the diagnosis of malignant biliary stricture

Introduction: Biliary stricture is a fixed narrowing of a focal segment of the bile duct that result in proximal biliary dilatation and clinical features of obstructive jaundice. A wide spectrum of hepatobiliary and pancreatic diseases, both benign and malignant, can result in the development of biliary strictures. Although trans abdominal ultrasound, computed tomography, and magnetic resonance imaging are sensitive for detecting bile duct pathology, they do not reliably distinguish strictures as being malignant or benign. FISH utilizes fluorescently labeled DNA probes to chromosomal centromeres or unique loci to detect cells that have numerical or structural abnormalities indicative of malignancy

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Aim of the study: To evaluate the accuracy of FISH in the diagnosis of malignant biliary stricture

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Patient and methods: Forty eight patients with indeterminate bile duct stricture presented with obstructive jaundice were prospectively enrolled and underwent ERCP and FISH over a period of 20 month from June 2013 to February 2015. Four patients were excluded because of loss follow-up. Thus, 44 patients were included in data analysis [17 males and 27 females]

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Results: The final diagnosis of stricture type was 32 malignant and 12 benign cases. FISH was positive in 30 cases and negative in 14 cases, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 93.75, 100.00, 100.0, 85.7, 95.5 and 0.969 respectively

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Conclusion: FISH increase the diagnostic accuracy of malignant biliary stricture. The sensitivity of FISH could improve the clinical management of patients being evaluated for malignant bile duct stricture by enabling a definitive diagnosis at an earlier stage in the clinical evaluation