Multiple Myeloma
Multiple myeloma is a plasma cell dyscrasia, in which there’s abnormal proliferation of antibody-producing plasma cells. There’s also a deficiency of functional antibodies, resulting in a relative hypo-gammaglobulinaemia and immunosuppression.
Presentation
CRAB:
Calcium (Hypercalcaemia) - due to increased osteoclast activity
Renal failure - due to light chain deposition and hypercalcaemia
Anaemia
Bone pain - osteolytic lesions, leading to pathological fractures and vertebral compression fractures
N.B. Marrow infiltration by the tumour can lead to other cytopenias e.g. thrombocytopenia, leukopenia.
Investigations
Initial investigations to do include:
Bloods - Calcium, U&E (renal impairment), FBC (anaemia)
XR/CT/MRI - looking for osteolytic lesions and pathological fractures
Diagnostic tests:
Serum and/or urine protein electrophoresis - shows a paraprotein spike (typically IgG)
Bence Jones protein (light chains) - raised
Bone marrow aspirate and biopsy - myeloma confirmed if > 10% of plasma cells
There are multiple tests that help determine the prognosis. These include:
CRP - the higher the level, the worse the prognosis
LDH - the higher the level, the worse the prognosis
Beta-2 microglobulin - the higher the level, the worse the prognosis
FISH and cytogenetic analysis
Management
A conservative approach is the best option if the patient has minimal symptoms and no end-organ damage. They may need therapy when there are signs of active disease.
Other options include stem cell transplant, and other non-chemotherapeutic drugs.
Supportive options:
Analgesia, bisphosphonates, and physio for bone disease
Flu and pneumococcal vaccines for infection prevention
EPO (± transfusion) for anaemia

