Chromosome Analysis, Leukemia/Lymphoma With Reflex to Chromosome Microarray (CMA)

Bone marrow, blood (>4% blasts required; see Collection), lymph node, spleen, bone core, or effusion

2 mL bone marrow, 3 mL peripheral blood, or 0.5 to 1 cm³ tissue

Bone marrow or peripheral blood in pediatric green-stopper (sodium heparin) tube; lymph node, spleen, bone core, or effusion in lymph node transport bottle

Patient should not be on chemotherapy.

Karyotyping, physical localization of copy number changes, and mapping of breakpoints involved in translocations for the diagnosis/prognosis of leukemia/lymphoma subgroups. The SNP assay will detect chromosomal imbalance that may be present in neoplastic disorders and clonal evolution.It provides detection of copy-neutral loss of heterozygosity of any chromosome, and the percent and location of homozygosity, that may be associated with cancer gene mutations.

In studies of myeloid malignancy (eg, MDS in blood), availability of immature blasts, excessive amounts of sodium heparin, or use of lithium heparin, or EDTA will inhibit growth of cell culture. The SNP assay does not detect balanced rearrangements, low-level mosaicism (<10%), marker chromosomes that only contain heterochromatin or tetraploidy.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Short-term cell culture; synchronization; chromosome harvest; G-banding; analysis (20 metaphases) and karyotyping; long-term β-mitogen cultures in some β-cell leukemias. Reflex to Reveal® microarray if chromosome analysis is normal. SNP microarray analysis is performed using the Cytoscan® HD platform, which uses more than 743,000 SNP probes and 1,953,000 NPCN probes with a median spacing of 0.88 kb.