FISH analysis for B Cell lymphomas
| Category | Specialist Integrated Haematological Malignancy Diagnostic Service (SIHMDS) >> Cytogenetics |
|---|---|
| Test background |
FISH involves the application of fluorescent DNA probes specific to genes or genetic regions of interest that highlight abnormalities involving these regions. |
| Clinical Indications |
Mature B-cell lymphoma can be low grade, intermediate grade, or high grade, and the prognosis and clinical course are highly variable. Genetic abnormalities have emerged as one of the most important prognostic markers in B-cell lymphomas and can aid in diagnosis. Several chromosome anomalies and variants of these anomalies have been associated with various lymphoma subtypes (see table below). Fluorescence in situ hybridization (FISH) permits the detection of these abnormalities in bone marrow samples and in FFPE lymph node samples. DLBCL/HGL: MYC, BCL2, BCL6, IGH |
| Reference range | N/A |
| Sample & container required | A minimum of 2-3mls Bone marrow in lithium heparin. 3-5mls peripheral blood in lithium heparin (if disease cells are present in sufficient numbers to allow cell culture and/or FISH studies, as appropriate) EDTA PB and BM samples (>1ml) are acceptable for FISH only studies as appropriate. Please note the laboratory does not provide transport medium. Samples sent in transport media from an external laboratory containing Lithium heparin will be accepted if no other media available FFPE Referrals 4 to 6 slides (1~2µm thick) with an H&E marked slide (essential in cases where only part of the tissue is infiltrated, or only part of the tissue is appropriate for screening) Sections should be mounted on APES-coated (or equivalent) positively charged slides. 6 slides for lymphoma cases |
| Sample volume | Samples would not be rejected on the basis of small volume, however, 5 mL is ideal. |
| Turnaround time | FFPE LYMPHOMA/BM Infiltrated by HGL/BL: 95% should be reported within 14 calendar days Post treatment follow-up samples are treated as routine; 95% should be reported within 21 calendar days |
| Notes | If the blood counts are abnormal (high or low white cell count) the volumes of BM/PB requested can be adjusted accordingly. For culture (karyotyping) a WCC of 5×10^6 cells per ml is optimal. Delayed samples: |