Multiple myeloma

• Multiple myeloma is a progressive malignant disease of the plasma cells that normally produce immunoglobulin — it affects multiple organs and systems including the bones, kidneys, blood, and immune system.
• The condition is characterised by a proliferation of abnormal monoclonal immunoglobulins in the blood, referred to as paraproteinaemia.
• Suspect multiple myeloma in adults, particularly over 60 years of age with:

  ·       Unexplained bone pain (often in the lower back or thoracic area).

  ·       Present in up to 60–70% of people and may have pre-existed for months.

  ·       Fatigue — present in about 30% of people.

  ·       Symptoms of hypercalcaemia (such as bone pain, abdominal pain, depression, confusion, muscle weakness, constipation, thirst, and polyuria) — present in up to 30% of people.

  ·       Multiple myeloma may present with other complications such as pathological fractures and recurrent infection.
• For people aged 60 years or older with persistent bone pain, particularly back pain, or unexplained fracture offer investigations including:

  ·       A full blood count, serum calcium, and plasma viscosity or erythrocyte sedimentation rate (ESR).
• For people aged 60 years or older with hypercalcaemia or leukopenia, and a presentation consistent with possible myeloma offer investigations including:

  ·       Very urgent (within 48 hours) serum electrophoresis, serum-free light-chain assay, and Bence-Jones protein urine assessment.
• For people whose plasma viscosity, ESR, or incidental findings on blood tests and presentation are consistent with possible myeloma consider:

  ·       Very urgent (within 48 hours) serum electrophoresis, serum-free light-chain assay, and Bence-Jones protein urine assessment.
• Be aware that serum/urine electrophoresis is negative in 1–5% of people with multiple myeloma, who have a 'non-secretory' form of the disease that produces no serum M protein or urinary Bence-Jones protein.
• Also consider the following additional investigations to help confirm the diagnosis of multiple myeloma:

  ·       Peripheral blood film — to look for rouleaux (aggregations of red blood cells), which might suggest underlying paraproteinaemia.

  ·       Serum urea, creatinine, electrolytes, and liver function tests — to detect renal impairment, raised uric acid from increased tumour cell turnover, and to determine total protein concentration, which is usually raised in multiple myeloma.

  ·       X-rays of symptomatic areas for people with bone pain — to rule out pathological fractures.
• In secondary care for investigation of MM:

  ·       Immunofixation of serum and urine, to confirm the presence of a paraprotein.

  ·       Bone marrow aspirate and trephine biopsy, with plasma cell phenotyping, to confirm the presence of monoclonal plasma cells in the bone marrow.
• Magnetic resonance imaging (MRI):

  ·       This is the gold standard to determine the extent of myeloma bone disease. Dedicated spine MRI is also used to investigate possible spinal cord compression.