Myeloma Flashcards
Pathogenesis
Malignant proliferation of plasma cells => diffuse bone marrow infiltrate => bone destruction and bone marrow failure
Over-production of immunoglobulin. Classified according to which Ig overproduced (IgG most common, then IgA) => dysfunction of organs
Other Igs are low => susceptibility to infection
Characterised by osteolytic bone lesions (increased osteoclast activation), renal disease and immunodeficiency
Risk factors
Second most common haematological malignancy
Age - median age at presentation is 70
Afro-Caribbean > Caucasian
M>F
Clinical features
Osteolytic bone lesions: Backache and bone pain, pathological fractures, osteoporosis, vertebral collapse, spinal cord/nerve root compression
Hyercalcaemia: bones, stones, groans, moans; abdo pain, vomiting, constipation, polyuria, polydipsia, depression, anorexia, weight loss, tiredness, weakness, hypertension, confucion, pyrexia, renal stones
Anaemia, netropenia, thrombocytopenia (marrow infiltration): symptoms of anaemia, infection, bleeding, lethargy
Recurrent infections due to immunoparesis and also as above
Renal impairment: due to light chain deposition and Ig induced glomeruli changes: dehydration, renal failure
Amyloidosis: cardiac failure, macroglossia, carpal tunnel
Neuropathy, dizziness, confusion, headaches, epistaxis
Hypervisocity: cerebrovascular event
Investigations - bloods
FBC: normocytic normochromic anaemia, leukopenia, thrombocytopenia
Film: rouleaux formation of RBCs
ESR or plasma viscosity: persistently raised
Ur and Cr: raised
Ca2+: raised (in 40%)
Alk phos: normal unless healing fracture
Ig levels
Imaging
Xrays: lytic lesions - punched out eg pepper pot skull; vertebral collapse; fractures; osteoporosis
CT/MRI: may detect lesions not shown on XR
Special tests
Serum and urine electrophoresis: Paraprotein monoclonal bands (Bence Jones proteins) (usually IgG or IgA)
Bone marrow film: many plasma cells, abnormal forms
Diagnostic criteria
1) Monoclonal protein band in serum or urine electrophoresis
2) Increased plasma cells on marrow biopsy
3) Evidence of end-organ damage from myeloma: hypercalcaemia, renal insufficiency, anaemia, bone lesions: do a skeletal survey: XR chest, spine, pelvis
MGUS
Monoclonal gammopathy of undetermined significance
Paraprotein found in blood but no other signs or symptoms of myeloma
Observe
Supportive management
Analgesia for bone pain (caution with NSAIDs - renal risk)
Bisphosphonates to reduce fracture risk and bone pain
Orthopoedic procedures can be usedful in vertebral collapse
Radiotherapy if focal disease
Correct anaemia with transfusion. Can use EPO
Renal failure: rehydrate and ensure intake 3L/day; dialysis if acute renal failure, potentially transplant
Treat infections quickly and empirically with broad spectrum abx. Regular IVIG may be needed if recurrent
Chemotherapy
If unsuitable for intensive radiotherapy
Also just in general, I think
Lots of different regimes - depending on age, fitness etc
Basically if elderly, melphalan and pred
If younger, more aggressive chemo + stem cell transplant
Can control disease, reduce paraprotein levels and bone lesions and increase time to relapse
Follow up
FBC, U+Es, serum and urine electrophoresis every 2-3 months
If bone pain: skeletal XR, MRI or CT to detect new lesions
Complications
Hypercalaemia Spinal cord compression Hyperviscosisty Acute renal injury Anaemia Infection Fractures Neuropathy Bleeding Amyloidosis
Hypercalcaemia
Occurs with active disease
30% patients
Rehydrate vigorously - NaCl 0.9% 4-6L/day (watch fluid balance - can give furosemide). If mild, can orally rehydrate
IV bisphosphonates useful for treating acutely, then continue PO
IV steroids and calcitonin if refractory
Spinal cord compression
Emergency
Urgent MRI
Dexa 8-16mg/24h PO
Local radiotherapy
Hyperviscosity
Reduced cognition, disturbed vision, bleeding
Plasmapheresis to remove light chains
Venesection if plasma exchange not viable
Start chemo
