Bone marrow in cytogenetic transport medium (preferred) or lithium heparin is usually the sample of choice, but peripheral blood in lithium heparin may be suitable if there are circulating blasts and/or a high white blood cell count. EDTA samples are only suitable in cases requiring FISH only (eg blood samples taken at diagnosis for exclusion of rapid identification of BCR::ABL1 when a bone marrow sample will shortly follow). If in doubt please use lithium heparin. Samples which are non-sterile, clotted or collected in sodium citrate, fixative or saline are not suitable.
To ensure appropriate analysis and interpretation it is important to provide clear and concise clinical information.
• Diagnosis. Rapid FISH tests (identification of BCR::ABL1 at diagnosis): 95% should be reported within 3 working days. The results of conventional cytogenetic analysis will be included in a final report, including any additional FISH, within 10 calendar days if rapid FISH was negative, or within 21 calendar days if rapid FISH was positive.
• Follow-up. Post treatment follow-up samples are treated as routine; 95% should be reported within 21 calendar days according to national guidelines. If sudden relapse and/or progression are suspected and a more rapid result is required please inform the laboratory.