Multiple Myeloma Flashcards
Define Multiple Myeloma
A haematological cancer characterised by clonal proliferation of plasma cells in the bone marrow, typically associated with a monoclonal component in the serum and/or urine.
Explain the aetiology / risk factors of multiple myeloma
AETIOLOGY
- This is a cancer of B-lymphocytes (Plasma cells) in the bone marrow which causes them to proliferate in the bone marrow - crowding out other cells in the bone marrow
- It produces DYSFUNCTIONAL monoclonal antibodies (mainly IgG, can be IgA) *
Myeloma can present with exclusively high light chains (and not the whole antibody - causing hypogammaglobulinaemia)
The M-protein/spike collectively refers to the paraprotein (dysfunctional IgG) or light chain components
RISK FACTORS:
- Monoclonal gammopathy of undetermined significance (MGUS) - this is the pre-malignant form that precedes MM
- FHx of MM
- Radiation exposure
- Really high or low Free Light-Chain (FLC) ratio (kappa/lambda)
Summarise the epidemiology of multiple myeloma
- This is a disease of the elderly
Recognise the presenting symptoms of multiple myeloma (acronym)
Think CRAB
- hyperCalcaemia: release of OAF, active osteoclasts resulting in resorption
- Renal failure: FLC is freely filtered and its accumulation can cause tubular obstruction (cast nephropathy) leading to AKI and/or CKD
- Anaemia: Crowding out of other cell lines means there are less RBCs
- Bone pain: The osteolytic lesions cause pain. They can also lead to compression fractures
Hypercalcaemia Sx:
- Bone pain (most common)
- Loin to groin pain (renal/ureteric calculi)
- Constipation
- Psychosis/confusion/depression
- Polyuria & Polydipsia
- Fatigue
Anaemia Sx:
- Fatigue/SOB (most common)
Bone Sx:
- Back pain
- Pathological fractures
Infections:
- RECURRENT CHEST INFECTIONS: Pneumonias due to lack of normally functioning immunolgobulin
Recognise the signs of multiple myeloma on physical examination
Hypercalcaemia:
- Flank/CVA tenderness
- Faecal impaction
Renal failure: nil
Anaemia:
- Pallor of conjunctive and nail beds
Infections:
- Fever
- Signs of pyelonephritis & Pneumonia
Identify appropriate investigations for multiple myeloma and interpret the results
- FBC: Normocytic/Macrocytic anaemia
- Renal dysfunction causing low EPO
- ESR is raised due to high serum protein
- Serum/urine electrophoresis:
- Serum electrophoresis shows ** dense narrow gamma band** (increased IgG/IgA/FLC)
- Urine electrophoresis shows increased FLC (Bence Jones) bands (increased urinary FLC)
- Serum free-light chain and ratio: High FLC and high ratio (light-chain restriction, monoclonal)
- Peripheral smear: May show rouleaux (non-specific)
- Bone marrow aspirate biopsy: monoclonal plasma cell infiltration ≥10%
- Serum calcium: Elevated
- Bone imagine (CT): ‘Punched out’ lytic lesions
- Urea & Creatinine: Raised creatinine and urea
Diagnosis & referral of myeloma
For people with incidental blood findings and/or symptoms suggestive of myeloma:
- Arrange VERY URGENT blood tests (within 48hrs) for serum electrophoresis, urine BJP and serum FLC assay
- Other non-urgent investigations to send:
- peripheral blood film (rouleaux)
- FBC
- U&E (AKI etc)
- corrected calcium
- Uric acid
- X-ray if bone pain
- Arrange a 2 week suspected cancer referral to haematology if these results come back positive (suggesting myeloma)
Arrange urgent hospital admission if:
* symptoms of metastatic SCC
* severe hypercalcaemia (>3.01)
Management
Management of myeloma is decided by haematologists & MDT (oncologists, palliative care, PT, OT) and depends on age, disease stage, prognosis and will likely include:
- combination of chemotherapy (e.g. thalidomide, cyclophosphamide, bortezomib)
- regular haematologist review
- bone density management (bisphosphonate)
- anaemia management (EPO, transfusion)
