Related Subjects:
|Hypercalcaemia
|Multiple Myeloma
|Extramedullary Plasmacytoma
|Smouldering Myeloma
|MGUS
|Waldenstrom Macroglobulinaemia
|Oncological emergencies
𦴠Plasmacytoma is distinct from multiple myeloma because there are no CRAB features (hyperCalcemia, Renal insufficiency, Anaemia, Bone lesions).
It usually presents as a single, localised mass in either bone or soft tissue.
π About
- Extramedullary Plasmacytoma (EMP): Soft tissue mass of clonal plasma cells, often in the head & neck (nasopharynx, sinuses, larynx).
- Solitary Bone Plasmacytoma (SBP): Single bone lesion without systemic involvement.
π¨ Men > women (2:1), median age ~55 yrs.
𧬠Aetiology / Pathology
- Localised clonal proliferation of plasma cells.
- Presents as a single lytic lesion or an isolated soft tissue tumour (confirmed by biopsy).
- Does not meet diagnostic criteria for multiple myeloma.
π©Ί Clinical Features
- Age: 50β80 yrs.
- Symptoms: localised bone pain, pathological fractures, or visible soft tissue mass.
- May cause compressive symptoms depending on location (ENT obstruction, spinal cord compression).
- Unlike myeloma: systemic symptoms (anaemia, renal dysfunction, bone marrow failure) are absent.
π Differentials
- Multiple myeloma (look for CRAB features, >10% marrow plasma cells).
- Other B-cell neoplasms (e.g. lymphoma).
- Metastatic bone disease.
π§ͺ Investigations
- Bloods: FBC, U&E, calcium β usually normal.
- Serum protein electrophoresis: Monoclonal spike in ~60% of cases.
- Monoclonal protein: Serum M-protein <30 g/L or Bence-Jones protein <500 mg/24h.
- Bone marrow biopsy: <10% plasma cells (excludes myeloma).
- Skeletal survey / CT / MRI: Punched-out lytic lesion Β± soft tissue extension.
- Check for absence of systemic disease (per IMWG diagnostic criteria).
π Management
- Radiotherapy: π¨ First-line. Curative intent with >80% local control rates.
- Surgery: Reserved for accessible extramedullary lesions (e.g. head & neck) or for stabilisation (spinal fixation).
- π§ Long-term follow-up:
Risk of progression to multiple myeloma is high (β50% within 10 yrs).
π‘ Teaching Pearls
- Think plasmacytoma when thereβs a single lytic lesion but no systemic myeloma features.
- SBP may precede myeloma β lifelong monitoring is essential.
- Radiotherapy is highly effective (unlike multiple myeloma, which needs systemic therapy).
- Always screen for CRAB features to distinguish from myeloma in exams/OSCEs.
π References
- International Myeloma Working Group (IMWG) diagnostic criteria.
- Kyle RA, Rajkumar SV. Multiple Myeloma and Other Plasma Cell Disorders. NEJM.