Myeloma — Plasma cell blood cancer

Plasma cells are an integral component of the immune system, normally synthesising targeted immunoglobulins to combat bacterial and viral infections. In myeloma, a single plasma cell undergoes malignant transformation and clones itself repeatedly within the bone marrow cavity. As these abnormal myeloma cells accumulate, they overcrowd normal haematopoietic stem cells, impairing the production of red blood cells, white blood cells, and platelets.

Furthermore, malignant plasma cells produce excessive quantities of an incomplete, dysfunctional monoclonal immunoglobulin, known as an M-protein or paraprotein. This paraprotein accumulates in circulation and filters through the kidneys, frequently precipitating renal dysfunction. The cancerous cells also dysregulate normal bone remodelling by stimulating osteoclasts, which dissolve bone tissue, whilst suppressing osteoblasts, causing painful lytic lesions and pathological fractures.

Understanding myeloma helps patients navigate a disease characterised by alternating periods of active treatment and remission. Because myeloma is rarely cured completely with conventional treatment, the primary clinical focus is achieving deep, prolonged disease control while preserving organ function and quality of life. Recognising the classic CRAB features—hypercalcaemia, renal insufficiency, anaemia, and bone lesions—empowers patients to report symptoms early, protecting vital kidney health and preventing debilitating skeletal injuries through prompt medical interventions.

Diagnosing myeloma requires evaluating bone marrow biopsies to quantify clonal plasma cell infiltration. Blood and urine protein electrophoresis (SPEP/UPEP) detect and monitor paraprotein levels, complemented by serum free light chain (sFLC) assays. Whole-body low-dose computed tomography (CT), magnetic resonance imaging (MRI), or PET-CT scans identify osteolytic bone lesions. Baseline testing routinely monitors serum calcium, creatinine, and haemoglobin levels.

Myeloma is a distinct haematological malignancy classified among plasma cell neoplasms. Related conditions along the disease spectrum include monoclonal gammopathy of undetermined significance (MGUS), an asymptomatic precursor state, and smouldering multiple myeloma (SMM), which carries an elevated risk of progression. It is closely related to other plasma cell disorders such as solitary plasmacytoma, AL amyloidosis, and POEMS syndrome.

Myeloma treatment has advanced substantially, relying on combination regimens rather than traditional chemotherapy alone. Standard therapies include proteasome inhibitors (e.g., bortezomib), immunomodulatory drugs (e.g., lenalidomide), monoclonal antibodies (e.g., daratumumab), and corticosteroids. Eligible patients often undergo autologous stem cell transplantation. Relapsed disease may be treated with innovative therapies including bispecific T-cell engager antibodies and chimeric antigen receptor (CAR) T-cell therapies.