INTERPHASE FLUORESCENCE IN SITU HYBRIDIZATION PANEL TEST FOR CHOLANGIOCARCINOMA

​The p16 gene at chromosome 9p21 is a tumor suppressor gene that is commonly inactivated in a wide range of malignant tumors. Homozygous deletion of the p16 gene is a commonly reported abnormality in cholangiocarcinoma. In addition, gains of chromosomes 3, 7 and 17 are also present in malignant bile duct strictures. Fluorescence in situ hybridization assays using a multiprobe set consisting of centromeric probes for chromosomes 3, 7 and 17 and p16 gene can be used as a diagnostic tool in detecting the genetic alterations in cholangiocarcinoma.

​Freshly-cut tissue sections or biliary duct brushings.

​The FISH test is optimal with freshly-cut tissue samples. Tissue sections should preferably be prepared between 4-6 microns in thickness on coated/positively-charged slides. The optimal fixation time in formalin should be between 6 - 72 hours. An accompanying Hematoxylin and Eosin (H&E) stained slide with the tumour region marked out by a pathologist should be submitted together with at least 3 unstained sections.

​Fluorescence In Situ Hybridization using direct-labelled FISH DNA probes are hybridized to target loci and analyzed under fluorescence microscopy. 

​Gains of chromosomes 3, 7 and 17 or homozygous deletion of p16.

FISH findings are reported in accordance to the International System for Human Cytogenomic Nomenclature (ISCN, 2024).

​3 ~ 10 days

​Monday - Saturday (office hours)