Multiple Myeloma.
Myeloma is a plasma cell neoplasm, which produces diffuse bone marrow infiltration and focal osteolytic deposits. A Monoclonal band is seen on serum or urine electrophoresis.
Peak age: 70yrs. Sex ratio is equal.
Classification is based on principal neoplastic cell product. 60% of IgG and IgA myelomas also produce free Ig light chains, which are filtered by the kidney and may be detectable as Bence Jones protein. These may cause renal damage or rarely amyloidosis.
Symptoms: bone pain, mainly back, ribs, long bones and shoulder - not extremities. Increased Ca, pathological fractures, hyperuricaemia, anaemia, infection, neuropathy, blurred vision and bleeding.
Examination: bone tenderness, urine, fundoscopy, for hyperviscosity-induced haemorrhages and exudates, macroglossia (amyloid).
Investigations: FBC, ESR (increasd), bone marrow, serum/urine electrophoresis, Ca increased, alk phos (normal), urea, creatinine and uric acid, increased, CXR, skeletal X-ray shows punched out lesions (pepper pot skull) and background osteoporosis.
Diagnosis: abundant plasma cell in marrow, M band or urinary light chains, osteolytic bone lesions.
Treatment: supportive: bone pain, anaemia and renal failure are the main problems so give analgesics and transfusions as needed. Solitary lesions may be given radiotherapy.
Chemotherapy: Melphalan is standard.
Prognosis: survival is worse if urea >10mmol/l or Hb <7.5gm/dl.
Dangers: Hypercalcaemia: IV saline, steroids eg hydrocortisone and consider diphosphonates.
Hyperviscosity: causing mental impairment, disturbed vision and bleeding. May need plasmapheresis.
Acute renal failure.