Multiple Myeloma

Question 1

Define

Answer 1

Haematological malignancy characterised by monoclonal proliferation of plasma cells resulting in bone lesions and production of a monoclonal immunoglobulin (paraprotein, usually IgG or IgA)

Main plasma cell dyscrasia (disordered state)
PCPs due to abnormal proliferation of a single clone of cells leading to secretion of Ig causing dysfunction of many organs

Paraproteinaemia
• Bence-Jones proteins in urine
• Narrow band on serum electrophoresis

Question 2

Causes

Answer 2

UNKNOWN

Possible viral trigger

Chromosomal aberrations are frequent

Associated with ionising radiation, agricultural work or occupational chemical exposures

Question 3

Risk factors

Answer 3

associated with ionising radiation, agricultural

work or occupational chemical exposures (e.g. benzene)

Question 4

Epidemiology

Answer 4

4/100 000 annually
Peak incidence in 70 years
Gender equal
Afro-Caribbean > Caucasian > Asian

Question 5

Symptoms

Answer 5

Bone pain (due to osteolytic bone lesions) – causing backache/rib pain, sudden and severe if caused by pathological fractures or vertebral collapse

• Lesions are due to ↑osteoclast activation from signalling by myeloma cells

Infections – often recurrent, due to immunoparesis

General – tiredness, thirst, polyuria, nausea, constipation, mental change (due to ↑Ca2+, hypercalcaemia)

Hyperviscosity – bleeding, headaches, visual disturbance

Question 6

Signs

Answer 6

• Blood → anaemia, neutropaenia, thrombocytopaenia due to marrow infiltrations, leads to pallor, purpura
• Tachycardia
• Flow murmurs
• Signs of HF
• Dehydration
• Hepatosplenomegaly
• Macroglossia
• Carpal tunnel syndrome and peripheral neuropathies
• Renal impairment due to light-chain deposition

Clinical features → CRAB

1. Calcium high
2. Renal failure
3. Anaemia
4. Bone pain

Bone problems may lead to vertebral collapse and compression of spinal cord → paralysis

Question 7

Identify appropriate investigations for multiple myeloma

Answer 7

Bloods

• FBC - low Hb, normochromic normocytic
• High ESR (and possible high CRP)
• U&Es - high creatinine, high Ca2+
• Normal ALP

Blood Film

• Rouleaux formation with bluish background (suggests high protein)

Serum or Urine Electrophoresis

• Serum paraprotein
• Bence-Jones protein (monoclonal immunoglobulin light chain that’s found in the urine and suggests multiple myeloma)

Bone Marrow Aspirate and Trephine

• High plasma cells (usually > 20%)

Chest, Pelvic or Vertebral X-Ray

• Osteolytic lesions without surrounding sclerosis
• Pathological fractures