Introduction to Lymphoma and Myeloma Flashcards
Define and outline Lymphoma
Lymphoma is a cancer of white blood cells (lymphocytes )
Affects to mature blood cells , mostly B lymphocytes but also T lymphocytes
Heterogeneous group
Many known to be due to specific genetic mutations and chromosomal translocations
What are the main functions of the lymphatic system ?
Blood filtration /purification
Removal of excess fluids from tissues
Absorption and transport of lipids
Immune system activation
What are the lymph nodes ?
small glands that filter lymph, the clear fluid that circulates through the lymphatic system.
What are lymph organs ?
Primary lymph organs :
sites where stem cells can divide and become immunocompetent
Secondary lymph organs : sites where most of the immune response occur
What are the primary lymph organs ?
Thymus
Bone Marrow
What are the secondary lymph organs ?
Tonsils and adenoids Lymph nodes Spleen Peyer's patches Appendix
How do Lymphomas develop ?
They affect lymphocytes in different maturation stages which leads to uncontrolled divison .
Organ size increase :
Lymph node ; Adenopathy
Other lymph organs: Splenomegaly
Spread to other tissues through the lymphatic system
Might infiltrate in bone marrow (detectable in blood ) and other organs
How is Lymphoma classified ?
Non Hodgkin’s (more common) (80-84)
Hodgins (75-79 years old)
What is the presentation of lymphoma ?
Fever Swelling on face Lump in neck,armpit or groin Excessive sweating at night Unexpected weight loss Loss of appetite Weakness Breathlessness Itchiness
How is lymphoma diagnosed ?
Through taking a lymph node biopsy using a biopsy needle
Following this : Flow cytometry FISH NGS Immunophenotyping
What is the staging of Lymphoma ?
This is a series of tests carried out by PET to identify where in the body is affected .
Stage 1: Localised disease , single lymph node region or single organ
Stage 2: Two or more lymph node regions on the same side of the diaphragm
Stage 3: Two or more lymph nodes regions above and below diaphragm
Stage 4 : Widespread disease multiple organs with/without lymph node involvement
What is the aetiology of Lymphoma ?
Multifactorial disorder :
Malfunctioning of the bodys immune system
Exposure to certain infections
Most lymphomas occur when a B cell develops/acquires mutations in its DNA
What is the traditional classification of Lymphoma ?
Hodgkin’s and Non Hodgkin’s with Hodgkin’s being the larger group.
Non Hodgkin’s -
Diffuse / Follicular
Hodgkin’s
What are the aspects does the WHO 2016 take into account ?
Mature B-cell neoplasms
Mature T-cell and NK neoplasms
Hodgkin lymphoma
What is Hodgkin lymphoma ?Outline the disease and its presentation
Clonal B-Cell malignancy
Presentation: Non-Painful enlarged lymph node
Risk factors : approx. 50% cases are due to Epstein Barr virus (EBV)
How can we diagnose Hodgkin’s Lymphoma ?
Excisional lymph node biopsy :
Observing Reed Sternberg cell which arise from normal B lymphocytes
These are bilobed nucleus
These are only present in Hodgkins lymphomas
What is the treatment of Hodgkin’s lymphoma ?
-Chemotherapy /radiotherapy and stem cell transplant
-Prognosis- 5 year survival
good results in young adults
What are Non -Hodgkin lymphomas ?
These are all lymphomas aprt from hodgkins lymphoma
Outline Non-Hodgkins Lymphoma
Presentation : Enlarged lymph nodes
Causes: Chromosome translocations
Risk factors : Virus infections in Burkitt’s lymphoma , Human T-cell leukaemia virus in adult T-cell lymphoma
What are the chromosome translocations which occour in Non-Hodgkins Lymphoma ?
Many lymphomas carry chromosome translocations involving the Ig heavy chain or light chain loci (chr14)
- Ig genes are highly expressed in B-cells
- Each Ig gene has a powerful tissue specific enhancer (high expression levels )
What are the consequences of these chromosome translocations in Non-Hodgkin lymphoma ?
The normal role of the enhancer is to activate the promoter of the rearranged V segment of the Ig
Due to the translocation between chromosome 14 and other chromosomes , the enhancer starts regulating the transcription of the other genes of the chromosome which has fused with chromosome 14.
There is an overexpression of the BCL-2 gene which is an apoptosis inhibitor.
Most cases of follicular lymphoma carry ty(14:18)(q32:q21)
What is Follicular Lymphoma ?
Follicular lymphoma is a type of non-Hodgkin lymphoma
What is the translocation observed in Burkitt’s lymphoma ?
t(8;14)(q24;q32)
c-myc is a potent proto-oncogene
What are the risk factors of Non-Hodgkin lymphoma ?
Virus infections
- It directly transforms B-lymphocytes in culture. Due to viral oncogene LMP-1
- Over half of all normal individuals carry latent EBV infection. They do not develop lymphomas due to effective immune surveillance by cytotoxic T-cells.
