Haematological Malignancy

Definition

Haematological malignancies are cancers that affect the blood, bone marrow, and lymph nodes. These cancers are generally classified into three main types: leukaemia, lymphoma, and myeloma. They disrupt the normal production and function of blood cells, leading to various complications.

Types

Haematological malignancies include several distinct types:

Leukaemia: Affects the white blood cells and is classified into acute and chronic forms, with further subdivisions based on the type of white blood cell affected (e.g., acute lymphoblastic leukaemia, chronic myeloid leukaemia).
Lymphoma: Affects the lymphatic system and is classified into Hodgkin and non-Hodgkin lymphoma.
Myeloma: Also known as multiple myeloma, it affects plasma cells in the bone marrow.

Aetiology

The exact cause of haematological malignancies is often unknown, but several factors can increase the risk:

Genetic mutations and predispositions
Exposure to radiation or certain chemicals
Viral infections (e.g., Epstein-Barr virus, Human T-lymphotropic virus)
Autoimmune diseases
Previous chemotherapy or radiation therapy

Pathophysiology

The pathophysiology varies with each type of haematological malignancy:

Leukaemia: Abnormal proliferation of white blood cells, which can accumulate in the bone marrow and suppress the production of normal blood cells.
Lymphoma: Abnormal lymphocytes accumulate in lymph nodes and other tissues, leading to immune system dysfunction.
Myeloma: Abnormal plasma cells produce monoclonal antibodies that can cause bone damage and impair normal immune function.

Risk Factors

Age (older individuals are at higher risk)
Family history of haematological malignancies
Exposure to certain chemicals (e.g., benzene)
Radiation exposure
Previous cancer treatment
Infections with certain viruses

Signs and Symptoms

Common signs and symptoms include:

Fatigue and weakness
Frequent infections
Easy bruising or bleeding
Swollen lymph nodes
Bone pain (in myeloma)
Unexplained weight loss
Night sweats
Pale skin (anaemia)

Investigations

Specific blood tests and other investigations depend on the suspected malignancy:

Leukaemia

Full blood count (FBC): To assess levels of different blood cells; leukaemia may show elevated white blood cells, anaemia, and thrombocytopenia.
Bone marrow biopsy: To examine the bone marrow for abnormal cells.
Flow cytometry: To identify specific types of leukaemia cells.
Cytogenetic analysis: To detect chromosomal abnormalities associated with leukaemia.
Molecular testing: To identify specific genetic mutations (e.g., BCR-ABL in chronic myeloid leukaemia).

Lymphoma

Full blood count (FBC): To check for anaemia, elevated white blood cells, or thrombocytopenia.
Biopsy of affected lymph nodes: To confirm the diagnosis and classify the type of lymphoma.
Imaging studies: CT, MRI, or PET scans to detect tumours or lymph node involvement.
Bone marrow biopsy: To check for bone marrow involvement.
Flow cytometry: To identify specific lymphoma cells.

Myeloma

Suspect myeloma in patients with symptoms such as bone pain (especially back pain), fatigue, recurrent infections, or unexplained anaemia. The CRAB criteria (Calcium, Renal function, Anaemia, Bone lesions) help in diagnosis:

Full blood count (FBC): To check for anaemia.
Calcium levels: Raised levels may indicate myeloma.
Renal function tests: To assess kidney function (e.g., creatinine, urea).
Erythrocyte sedimentation rate (ESR): Usually raised in myeloma.
Serum protein electrophoresis and immunofixation: To detect abnormal proteins (paraproteins).
Serum free light chains: To measure free light chains produced by myeloma cells.
Immunoglobulins: To check levels of different immunoglobulins (IgG, IgA, IgM).
Bone marrow biopsy: To examine the bone marrow for myeloma cells.

Management

Primary Care Management

Referral to a specialist: Patients with suspected haematological malignancy should be referred to a haematologist or oncologist for further evaluation and management.
Initial management: Supportive care, such as blood transfusions for anaemia, while awaiting specialist input.

Specialist Management

Chemotherapy: To kill or stop the growth of cancer cells.
Radiotherapy: To target and kill cancer cells in specific areas.
Immunotherapy: To boost the body's immune system to fight cancer.
Targeted therapy: Drugs that specifically target cancer cell mechanisms.
Bone marrow transplant: To replace damaged bone marrow with healthy cells.
Monitoring and supportive care: Regular follow-ups to monitor disease progression and manage symptoms.

References

NHS. (2024). Blood Cancer. Retrieved from NHS
St George's University Hospitals NHS Foundation Trust. (2024). Haematological Cancers. Retrieved from St George's NHS
North Bristol NHS Trust. (2024). Haematological Malignancy Diagnostics. Retrieved from North Bristol NHS
Royal Devon and Exeter NHS Foundation Trust. (2024). Blood Cancer. Retrieved from Royal Devon NHS