Flashcards in Marginal Zone Lymphomas Deck (6):
What are the 3 distinct subtypes of MZLs?
1) Extranodal MZL of mucosa-associated lymphoid tissue (MALT)
2) Nodal MZL
3) Splenic MZL
What are some common infectious pathogens a/w MZLs?
How often is Hep C a/w MZLs?
Esp splenic MZL
HCV has also be reported in about 35% of patients with non-gastric MALTs
What is commonly difficult to separate from MZL as a diagnosis?
Any mutations you know of that can help?
Waldenstrom's Macroglobulinemia/Lymphoplasmacytic lymphoma (WM/LPL)
MYD88 L265P somatic mutation is widely prevalent in WM/LPL patients
IGHV analysis clearly distinguishes splenic MZLs and WM/LPL
- Splenic MZLs were characterized by over representation of IGHV1-2 gene rearrangements with low/intermediate mutation rates
- WM/LPL a/w over-representation of IGHV3-23 rearrangements and high mutation rates.
Tell me about the epidemiology of MALT
GI tract most common site of involvement. 50% of MALT lymphomas.
Within GI tract, stomach 80-85%
Other common non-gastric sites include: Orbit, lung, skin
MALT lymphomas tend to be indolent.
Similar long-term outcomes between gastric and non-gastric subtypes.
T(11;18) most common translocation, resulting in formation of chimeric fusion Gene, API2-MALT1
- frequently detected in gastric, pulmonary MALT lymphomas
T(1;14) results in overexpression of BCL10 protein and it occurs in 1-2% of MALT lymphomas.
T(11;18) and BCL10 overexpression a/w locally advanced disease and is less likely to respond to H.Pylori eradication with antibiotic therapy.
T(14;18) results in deregulated expression of MALT1 Gene
- in 15-20% of MALT lymphomas
T(3;14) results in up emulation of FOXP1 Gene, a/w MALT of thyroid, ocular adnexa and sin