Introduction To Lymphomas And Myelomas Flashcards
Define lymphoma
cancer of white blood cells (lymphoctes)
- affects mature blood cells mostly B and T lymphocytes
What genetic sturcure is associated to lymphoma?
Many specific genetic mutations and chromosomal translocations
What is the main functions of lymphatic system? (4)
1) blood filtration / purification
2) removal of excess fluids from tissues
3) absorption and transport of lipids
4) immune system activation
What are primary lymph nodes? + examples
Sites where stem cells divide and become imunocompetent
- bone marrow and thymus
What happens in seconary lymph nodes + examples
Sites where most of immune responses occurs
- spleen, peyer’s patches, lymph nodes, tonsils
How do lymphomas develop stage wise?
Lymphocytes affected in diff maturation states due to genetic alteration
Uncontrolled division of the lymphocytes
Orga size increases e.g. splenomegaly(spleen), adenopathy (lymph node)
Spreads to other tissues through lymphatic system
Infiltrate into bone marrow - detectable in blood and/or other organs
What is the classification of lymphomas?
Non hodgkin lymphoma - most common - separates into either diffuse or follicular
Hodgkin lymphoma
Presentation of lymphoma
Enlarged lymph nodes, normally painless Excessive night sweats Unintended weightloss Itching Constant tiredness
How do you diagnose lymphoma?
Lymph node biopsy - flow cytometry, FISH, NGS and immunophenotyping
How do you diagnose stage of lymphoma after diagnosing lymphoma?
PET scan (positon emission tomography)
What are the 4 stages of lymphoma?
Stage 1 - localise - single lymph node / organ
Stage 2 - 2 or more lymph nodes but on same side of diaphragm
Stage 3 - 2 or more lymph nodes but on diff sides of diaphragm
Stage 4 - widespread, multiple organs with or without lymph node involvement (liver and bone marrow)
What causes lymphoma?
Multifactorial - malfunction to body’s immune system and exposure to certain infections
usually B cell develops a mutation in its DNA
Risk factors of hodgkin lymphoma
Epstein barr virus
Familt history
HIV/AIDS
How does Hodkin lymphoma present?
Non painful enlarged lymph nodes
How do you diagnose hodkin lymphma?
Excisional lymph node biopsy
- look for reed - sternberg cells (hodgkin cell only in hodgkin lymphoma)
What are reed sternberg cells?
Hodgkin cells
Multinucleated red stem cells in lymph nodes - only in Hodgkin not non hodgkin lymphoma
What is the treatment for hodgkin lymphoma?
Chemotherapy and sometimes radiotherpay too.
Stem cell transplant
What is non-hodgkin lymphoma?
all lymphomas apart from hodgkin lymphomas
How does non hodgkin lymphoma present?
Enlarged lymph nodes + general symtoms including night swears, fever and weight loss)
What is the cause of non hodgkin lymphoma?
Chromosomal translocation
esp involving Ig heavy chain or light chain loci on chromosome 14
- each Ig gene has powerful tissue specific enhancer
What are risk factors of non hodgkin lymphomas?
virus infections (EBV) driven lymphomas in immunosuppressed pateints e.g Burkitt's lymphoma Human T cell leukemia virus in adult T cell lymphomas
What is the normal role of an enhancer ig Ig genes? and how does it contribute to lymphomas?
Activate promoter of rearrnaged V segment
If rearrnaged infront of oncogene during chromosomal translocation, enhancer promotes expression of oncogene protein = non hodgkin lymphoma
What chromosomal translocation happens in non hodkin lymphoma?
Translocation between chromosome 14 and 18 bringing the enhancer infront of BCL-2 gene causing overexpression of BCL-2
What is BCL-2 gene?
encoded for BCL-2 (an apoptosis inhibtor) enahnced = excess cel proliferation due to low apoptosis
