| Description |
Several other peripheral B cell lymphomas may transform to DLBCL, a
process known as Richter Syndrome. This lymphoma frequency presents
as a single extranodal or nodal mass. Presence in bone marrow is prognostically
bad. Microscopically, the cells are large: centroblasts and immunoblasts.
The nuclei may appear vaculoated because the nuclear chromatin accumulates
at the nuclear membrane. |
| Frequency |
DLCBL accounts for 20-40% of NHL, but the majority of agressive lymphomas.
All ages are affected. |
| Cytogenetics |
| Locus |
Product |
Description |
| t(14;18) |
IgH-bcl-2 fusion |
Like follicular center lymphomas,
this lymphoma may express the anti-apoptotic protein bcl-2. |
| chromosome 3 |
bcl-6
Zinc-finger protein |
Associated with immune deficiency states and infection with eithe EBV
or human herpes virus 6. |
|
| Markers |
| Positive |
B-cell antigens (CD19, CD20, CD22, CD79a) |
| +/- |
cIg, sIg (often), bcl-2 |
| Negative |
tdT (as this is a peripheral, ie, mature B cell lymphoma) |
|
