INTERPHASE FLUORESCENCE IN SITU HYBRIDIZATION TEST FOR LYMPHOMA AND SOLID TUMOR TISSUES ON PARAFFIN-EMBEDDED SECTIONS OR TISSUE IMPRINTS

​Refer to Table 1.
Lymphoma probes include ALK breakapart (BA), BCL2(BA), BCL6(BA), c-MYC(BA), IGH/c-MYC(DF), BIRC3/MALT1(DF), IGH/CCND1(DF), IGH(BA), IGH/BCL2(DF) and MALT1(BA). 

Solid tumour tissues probes include ALK(BA), EWSR1(BA), SS18(BA), MDM2, DDIT3(BA), FUS(BA), FOXO1(BA), MET, ROS1(BA), PIK3CA and RET(BA).

Variant translocations can be detected using breakapart probes. For MDM2, amplification of the gene defines aggressive well-differentiated liposarcoma. For MET, increased gene copy number is an independent negative prognostic factor in NSCLC.

For lung adenocarcinomas, Lung Cancer FISH Panel consisting of ALK(BA), ROS1(BA), MET and RET(BA) probes can be tested concurrently.

For Diffuse Large B-Cell Lymphoma (DLBCL), Lymphoma FISH Panel consisting of BCL6(BA), MYC(BA) and BCL2(BA)probes can be tested concurrently.

​Freshly-cut tissue sections or tissue imprints. Bone marrow aspirates can only be used if there is lymphomatous involvement.

​The FISH test is optimal with freshly-cut tissue samples. Tissue sections should preferably be prepared between 4-6mm in thickness on coated/postively-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 for each FISH probe.

​Normal or Abnormal signal pattern depending on the probe construction.

1. Dual Fusion (DF) probe: Typical abnormal signal pattern is 2 fusions, 1 red and 1 green pattern. Variant pattern is outside the normal range.
 
2. Breakapart (BA) probe: Typical abnormal signal pattern is 1 fusion, 1 red and 1 green pattern. Variant pattern is outside the normal range.

3. Enumeration probe: Ratio of target gene to internal control probe ≥2.0 or >5 copies of the target gene is considered as amplified.
FISH findings are reported in accordance to the International System for Human Cytogenomic Nomenclature (ISCN, 2024).

​3 ~ 10 days

​Monday – Saturday (office hours)