F BCL2; FP BCL2
B-cell lymphoma (BCL), Non-Hodgkin lymphoma (NHL), Follicular lymphoma (FCL)
Fluorescence in situ Hybridization (FISH)
2.0 mL (min. 1.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
1.0 mL (min 0.5 mL) bone marrow in sodium heparin preferred, EDTA accepted
5mm^3 fresh tissue or 3.0 mL (min 2.0 mL) FNA in MPLN RPMI media
10% neutral buffered formalin fixed paraffin embedded tissue
Whole blood and bone marrow, ship ambient
Fresh tissue, FNA or FFPE ship in a Styrofoam container with a cool/refrigerated pack (Do not allow cool pack to directly contact sample)
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells; Improper fixative
FISH results indicate whether translocation is present or absent.
A normal cell results in a two orange, two green signal pattern. In an abnormal cell containing a t(14;18), the pattern is one orange signal, one green signal and two orange/green (yellow) fusion signals representing the two derivative chromosomes.
BCL2 blocks apoptosis and maintains long-term immune responsiveness including B-cell memory. The most frequent non-random chromosome rearrangement in non-Hodgkin lymphoma (NHL) of B-cell type is t(14;18)(q32;q21), which is found in approximately 50–85% of follicular lymphomas, 15–30% of diffuse large B-cell lymphomas, and occasionally in other histological subtypes of NHL. Molecular studies of this translocation have disclosed a juxtaposition of BCL2 gene in 18q21.3 with IGH gene locus at 14q32.33. Consequently, the BCL2 gene is subjected to the control of the IGH EA enhancer leading to the over expression of the anti-apoptotic protein BCL2. FISH can detect this translocation in either interphase or metaphase cells.