Related Subjects:
|Hypercalcaemia
|Multiple Myeloma
|Extramedullary Plasmacytoma
|Smouldering Myeloma
|MGUS
|Waldenstrom Macroglobulinaemia
|Oncological emergencies
Plasmacytoma is distinct from multiple myeloma due to the absence of hypercalcemia, renal insufficiency, anemia, and multiple bone lesions. It can present as a single mass, either in the bone or soft tissue.
About
- Extramedullary Plasmacytoma: A soft tissue mass composed of clonal plasma cells, localized and often found in the head and neck region.
- Solitary Bone Plasmacytoma: Localized bone lesion without systemic involvement. Men are more commonly affected than women (2:1 ratio).
Aetiology
- Typically, a single lytic bone lesion or an isolated soft tissue mass composed of clonal plasma cells identified via biopsy.
Clinical Features
- Affects adults aged 50-80 years, with a median age of 55.
- Symptoms include localized bone pain, pathological fractures, and soft tissue masses.
- Rare presentation, either as a bone marrow lesion or an extramedullary tumour.
Differentials
- Multiple Myeloma
- Other B-cell proliferative disorders
Investigations
- Blood tests: Full blood count (FBC), U&E, and calcium levels are typically normal.
- Serum Protein Electrophoresis: Monoclonal spike present in approximately 60% of cases.
- Monoclonal protein levels: Serum protein <30g/L or Bence-Jones protein <500mg/24h.
- Bone Marrow Biopsy: Monoclonal plasma cells <10% to confirm localized disease.
- Skeletal Surveys: X-rays or CT scans show punched-out lesions and assess for other primary tumours.
- Imaging: Punched-out lesions with well-defined borders, often eroding or expanding bone cortex. Soft tissue masses are visible on imaging as well.
- Absence of CRAB (hypercalcemia, renal insufficiency, anemia, bone lesions) criteria and no systemic involvement according to the International Myeloma Working Group (IMWG).
Management
- Radiotherapy: The primary treatment for plasmacytoma. Radiotherapy is highly effective, with local control rates of >80%, and is often given with curative intent.
- Surgery: May be considered for extramedullary plasmacytoma, particularly when located in the head, neck, or other accessible soft tissues.
- Plasmacytoma can progress to multiple myeloma in many cases, with a life expectancy of 7-10 years post-progression.