Lymphomas and Myelomas

Question 1

What are the primary and secondary lymph organs?

Answer 1

Primary lymph organs = sites where stem cells can divide and become immunocompetent

Secondary lymph organs = sites where most of the immune responses occur

Question 2

What is lymphoma?

Answer 2

= cancer of white blood cells (lymphocytes)

• Affects mature blood cells, mostly B-lymphocytes and T-lymphocytes
• Many risk factors are due to genetic mutations or chromosomal translocations

Question 3

What is a lymph and the lymphatic system?

Answer 3

Lymphatic system:

• Provides blood filtration and purification
• Removes excess fluids from tissues
• Absorbs and transports lipids
• Immune system activation

Lymph = fluid that accumulates in spaces between tissue cells, containing fats, proteins, lipids and lymphocytes

Question 4

How do lymphomas develop?

Answer 4

Question 5

What is the signs and diagnosis of lymphomas?

Answer 5

Signs:

• Swelling of the neck
• Fever
• Sweating
• Loss of appetite
• Unexpected weight loss

Diagnosis:

• Lymph node biopsy
• Then FISH, NGS or flow cytometry
• Staging - 1 to 4

Question 6

What is the aetiology of lymphomas?

Answer 6

Multifactorial:

• Exposure to certain infections
• Malfunctioning of the body’s immune system

= Mostly occurs when a B cell develops a mutation in its DNA

Question 7

What is a hodgkin lymphoma?

Answer 7

Clonal B-cell malignancy

No-painful enlarged lymph node

Diagnosis from biopsy - ‘eyes’

Treatment - chemotherapy and radiotherapy and stem cell transplant

Question 8

What is a non-hodgkin lymphoma?

Answer 8

Presentation - enlarged lymph nodes

Risk factors - virus infections eg. human T-cell leukaemia virus in adult T-cell

Causes: chromosome translocations

• Lymphomas carry chromosome translocations involving Ig heavy chain or light chain loci
  
  • Ig genes are highly expressed in B-cells

Classification:

• Low grade - divide slowly, behave in indolent fashion
• High grade - loss of normal tissue architecture, divide rapidly, life-threatening

Diagnosis:

• Immunophenotyping
• Cytogenetics - FISH for chromosome translocations
• Light chain restriction
• PCR

Treatment:

• Chemotherapy
• Radiotherapy
• Stem cell transplant

Question 9

What is a myeloma?

Answer 9

= tumour of bone marrow that involves plasma cells (antibodies production)

• Presentation - no initial symptoms, later bone pain, bleeding and anaemia
• Unknown cause - risk factors, obesity, radiation, family history and certain chemicals

Question 10

What are the clinical features of myelomas?

Answer 10

1. Suppression of normal bone marrow, blood cell and immune cell function
2. Bone resorption and release of calcium

• Myeloma cells produce cytokines –> stromal cells release RANKL –> osteoclasts activation –> lytic lesions of bone
• Calcium released form bone causes hypercalcemia

3. Pathological effects of paraprotein - single monoclonal Ig in the serum high levels when you have malignancy
   * Precipitates in kidney tubule causing renal failure

Question 11

How can you diagnose and treat myelomas?

Answer 11

Diagnosis:

• Urine electrophoresis
• Bone marrow biopsy for increased levels of plasma cells
• Serum electrophoresis for paraprotein
• Flow cytometry to detect cause

Treatment:

• Radiotherapy
• Chemotherapy - thalidomide, bortezomib
• Targeted therapies
• Immunotherapy