IGH/MAFB
Methodology
FISH
Test Description and clinical significance
Probes
14q32.33/20q12
Disease:
Multiple Myeloma, MGUS
t(14:20) gene fusions involving the IGH gene at 14q32 and the MAFB gene at 20q12 are seen in multiple myeloma and MGUS. Presence of an IGH-MAFB rearrangement is a sign of poor prognosis in myeloma.
Specimen Requirements
Collection:
The ordering pathologist will decide whether to order a conventional FISH preparation or a Plasma-cell enrichment (PCE) FISH preparation.
Bone Marrow Aspirate: 1~2mL in Green top (Sodium Heparin) tube OR Lavender top (EDTA) tube. Plasma cell enrichment eligible.
Peripheral Blood: 2~5mL Green top (Sodium Heparin) tube OR Lavender top (EDTA) tube. Plasma cell enrichment eligible ONLY IF circulating plasma cells are noted in PB.
Fresh, Unfixed Tissue: Tissue in RPMI. A conventional FISH preparation will be performed as plasma cell enrichment can not be performed on fresh tissues.
Fluids: Equal parts RPMI to specimen volume. A conventional FISH preparation will be performed as plasma cell enrichment can not be performed on fresh fluid tissues.
Paraffin Block: H&E slide and paraffin block. Plasma cell enrichment can not be performed on paraffin embedded tissues. Enumeration probe types (1p36/1q25, 13q14.2/13q34, CEN9, and TP53/CEN17) are not compatible with paraffin embedded tissues.
Cut Slides: H&E slide and 1 unstained slide (cut at 4 microns) per probe. Plasma cell enrichment can not be performed on paraffin embedded tissues. Enumeration probe types (1p36/1q25, 13q14.2/13q34, CEN9, and TP53/CEN17) are not compatible with paraffin embedded tissues.
Stability:
120 Hours/48 hours
Unacceptable Conditions:
DO NOT FREEZE
Storage & Transport
Room Temperature/Refrigerated (2–8°C )
CPT(s)
88377
New York Approved
YES
TAT
2 Days
*The CPT codes provided are for informational purposes only and are based on AMA guidelines The billing party is solely responsible for correct CPT coding.
