f) Plasma Cell Neoplasms

Plasma cells are differentiated B-lymphocytes that are specialised in producing immunoglobulin. A plasma cell neoplasm is formed by the uncontrolled expansion of a single clone of these cells. The most commonly encountered malignancy is the plasma cell myeloma (or multiple myeloma), which by itself accounts for about 10-15% of haematological malignancy. Other important entities include:

  • Monoclonal gammopathy of undetermined significance
  • Solitary plasmacytoma
  • Primary amyloidosis

Plasma Cell Myeloma


Myeloma is an uncommon malignancy, accounting for 1% of all cancers and 10-15% of haematological tumours. It is slightly more common in men; it never occurs in children and most patients are aged over 50 (median age 70). There is an 4-fold increased of myeloma in first degree relatives with myeloma.


Although most patients have no identifiable cause, there is a suggestion that chronic exposure to occupational antigens or radiation may be a contributing factor.

Natural History

Myeloma is typically widespread at diagnosis.

Clinical Features

Aetiology and Pathogenesis

Individual causative factors

Natural History

Precursor lesions
Modes of spread

Clinical Presentation

Blood Findings
Imaging Findings

Tumour/Normal Tissue Features

Laboratory Diagnosis
- macroscopic, microscopic, architecture, grading, growth patterns, immunohistochemistry, molecular techniques, serum markers

Staging / Classification

TNM or other staging system if relevant