Waldenstrom Macroglobulinaemia

Exam Cram

• Type of lymphoma & plasma cell dyscrasia

• The cancerous B lymphocyte (lymphoma) becomes a cancerous plasma cell producing excess antibodies

• Excess IgM (a large/ macro immunoglobulin)  antibodies causes hyperviscosity 

• Hyperviscosity symptoms: headache, systemic and stroke like symptoms

Outline

Background 

It is worth recapping some fundamentals in order to explain this condition. Bone marrow stem cells have a number of steps before their ultimate cell and haematological cancers are defined by which cell at which stage has become affected. 

Bone marrow stem cells divide into myeloid or lymphoid cells in the bone marrow. Lymphoid cells differentiate into B Lymphocytes, T lymphocytes or natural killer cells- which reside in the lymph glands. Cancer of lymphocytes (B cells, T cells or natural killer cells) is called lymphoma. B cells do not produce antibodies (immunoglobulins) however they develop into plasma cells which do. 

Waldenstrom's macroglobulinaemia (WM) is a type of B cell lymphoma and B cell dyscrasia. A unique type where the cancer B cells becomes a cancerous plasma cell that produces excess antibodies. In WM the excess antibodies produced are IgM (large antibodies). 

Waldenstrom's macroglobulinaemia can be broken into:

• Waldenstrom's- name of scientist discovered 

• Macro- large 

• Globulinaemia- antibodies in the blood. 

These large antibodies cause the blood to become too thick 'hyper viscous' which produce the symptoms typical of WM, e.g. headaches. 

Clinical

History:

• Hyper-viscosity: headaches, blurred visions

• Systemic: fatigue, weight loss

• Microthrombi: bleeding gums

• Stroke symptoms: focal neurology

Examination:

• Purpuric rash

Investigations

• Bone marrow biopsy

• Raised IgM levels

• Mildy anaemia 

• Mildly raised creatinine

• Normal calcium, WCC, platelets

Diagnosis

Diagnostic criteria: [1,2]

• Bone marrow biopsy: > 10% infiltration

• Raised IgM

• Symptoms: e.g. hyperviscosity, systemic or stroke, 

Differentials: Myeloma, Amyloidosis

See Plasma Cell Dyscrasias for further explanation and comparison of plasma cell disorders. 

Management

1. Rituxumab, cyclophosphamide, dexamethaonse

2. Plasma Electrophoresis 

References

1. Waldenström macroglobulinaemia. Available at: https://myeloma.org.au/wp-content/uploads/2017/10/WM_guidelines_FINAL.pdf (Accessed: 02 October 2024).

2. Dogliotti, I. et al. (2023) Diagnostics in Waldenström’s macroglobulinemia: A consensus statement of the European Consortium for waldenström’s macroglobulinemia, Leukemia. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9898035/#:~:text=The%20Consensus%20Panel%20Recommendations%20from,bone%20marrow%20(BM)%20biopsy%20( (Accessed: 02 October 2024).

Page written in 2024. 

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