Haematology 4 - Lymphoma 1 Flashcards
Which main classification of lymphoma is most common?
NHL (80%)
Why are lymphocytes prone to lymphoma -give 3 reasons
1) Rapid proliferation in response to infection
2) VDJ recombination
3) Highly dependent on apoptotic processes so if this goes wrong then –> proliferation of abnormal cells
Where does VDJ recombination occur?
In the bone marrow
2 stages of immunoglobulin and TCR gene recombination
1) VDJ recombination
2) Class switch recombination
Enzyme involved in VDJ recombination
RAG1 + RAG2
Enzyme invovled in class switching/somatic hypermutation
Adenosine induced deaminase (AID)
Examples of oncogenes in lymphoma
Cyclin D1 Bcl-2Bcl-6 c-Myc
Risk factors for lymphoma
Constant antigen stimulation (Autoimmune disease) e.g. H.pylori/coeliac
Viral infection: HTLV-1/EBV
H.pylori –> what kind of lymphoma?
Gastric MALT = marginal zone lymphoma of stomach
Sjogren’s –> –> what kind of lymphoma?
MZL of salivary glands
Hashimoto’s thyroiditis –> what kind of lymphoma?
MZL of thyroid gland
Coeliac disease –> what kind of lymphoma?
EATL (type of NHL)
Loss of T cell function can give ries to which infection-driven lymphoma?
EBV driven B-cell NHL lymphomas
Chronic untreated HIV infection is associated with increased incidence of lymphoma via which mechanism
Loss of T-cell function + EBV driven B cell proliferation
In the B cell follicles, where can naive B cells be found?
In the mantle zone
Where are T cells found?
Paracortex
Where do mature B cells end up
Central medulla
What is found in the germinal centre?
B cells and APCs
Main immunohistochemistry markers for B, T cells and macrophages
B cells = CD19,20
T cells = CD3, CD5
Macrophages = CD68
What is the most common subtype of NHL?
B cell
Neoplastic lymphomas tend to be disseminated at presentation but there is an exception
The exception is HL, where usually only 1 or 2 LN groups are affected
Why are there so many types of lymphoma?
Lymphomas can arise from any stage of lymphocyte development
Where do the cells arise from in Hodgkin’s lymphoma?
Germinal centre
On histology of lymphoma, what are large cells suggestive of?
High grade
