Synonyms

• Multiple myeloma
• myeloma

Category

Bone

Behaviour

Malignant

Grade

High

Gender

Male

Tissue of Origin

Other

Epidemiology

• Most common primary Bone malignancy in adults >65 years
• Peak incidence 7th decade
• Male predominance
• Clonal plasma cell malignancy

Clinical Features

• Bone pain (back pain most common)
• Fatigue and anaemia
• Renal dysfunction
• Infections

Location

• Spine, pelvis, ribs (most common sites)
• Proximal long Bones
• Skull

Imaging

• Plain radiograph: multiple punched-out lytic lesions
• MRI spine: evaluates marrow involvement and cord compression
• PET-CT: disease burden and activity

Pathology

• Sheets of abnormal plasma cells
• CD38+, CD138+
• Monoclonal immunoglobulin production (M protein)

Genetics

• Recurrent translocations t(4;14), t(11;14), t(14;16)
• TP53, KRAS mutations

Treatment

• Proteasome inhibitors (bortezomib), IMiDs (lenalidomide)
• Chemotherapy (VAD, doxorubicin, melphalan)
• Autologous stem cell transplantation if eligible
• Radiation for focal lesions causing pain/cord compression

Prognosis

• Incurable but Variable survival with modern therapy
• Median OS 5-7 years (improved with proteasome inhibitors/IMiDs)

Key Points

• Most common primary Bone malignancy in older adults
• Workup requires comprehensive staging
• Reversible disease with continuous treatment

Workup - Blood Tests

• FBC, U&E, LFTs, Bone profile - baseline
• Calcium (check hypercalcaemia)
• Monoclonal protein (SPEP) and free light chains - diagnostic
• LDH, beta-2 microglobulin - prognostic

Workup - Local Imaging

• Plain radiography: skeletal survey for lytic lesions
• MRI spine and pelvis - Bone marrow infiltration
• PET-CT - disease burden and prognostic

Workup - Biopsy

• Bone marrow trephine biopsy - diagnostic (>30% plasma cells)
• Cytogenetics and FISH on plasma cells for risk stratification

Workup - Staging

• Revised International Staging System (R-ISS)
• FISH for t(4;14), t(11;14), del(17p)
• TP53 mutation status

Workup - Other

• Haemato-oncology MDT mandatory
• Baseline cardiac assessment if on doxorubicin
• Renal function optimisation