Myeloma Flashcards
What is myeloma?
Cancer affecting plasma cells in the bone marrow
Cancer in a specific plasma cell causes large production of a specific paraprotein , which is an abnormal antibody or part of an antibody
What are plasma cells?
B lymphocytes that produce antibodies
What is multiple myeloma?
Myeloma affects multiple bone marrow areas in the body
What is monoclonal gammopathy of undetermined significance?
Production of a specific paraprotein without other features of myeloma or cancer
Incidental finding in otherwise healthy person
Small risk of progression to myeloma (1% per year)
What is smouldering myeloma?
Abnormal plasma cells and paraproteins
No organ damage or symptoms
Greater risk of progression to myeloma (10% per year)
What is the pathophysiology of myeloma?
Plasma cells are B lymphocytes that have produce a specific antibody
There are 5 types of antibodies, AGMDE
Myeloma is a cancer of a single plasma cell, with a genetic mutation causing rapidly uncontrollable multiplication
Leads to paraproteinemia due to abnormally high production of paraprotein
In myeloma what part of the antibody is affected more commonly?
Light chain
What are Bence Jones proteins?
Free light chains in urine
What are the features of myeloma?
CRAB
Calcium (raised)
Renal failure
Anaemia
Bone lesions and bone pain
What is the most common complication of myeloma?
Pancytopenia
Bone marrow is invaded causing suppression of blood cell lines leading to anaemia, leukopenia and thrombocytopenia
What type of anaemia occurs in myeloma?
Normocytic normochromic
What causes myeloma bone disease?
Increased osteoclast activity and suppressed osteoblast activity
Caused by cytokine release from abnormal plasma cells and other nearby cells
Patchy bone metabolism, does not affect everywhere
What are the common sites of myeloma bone disease?
Skull
Spine
Long bones
Ribs
What are the patches of thin bone called in myeloma bone disease?
Osteolytic lesions
What does myeloma bone disease lead to?
Pathological fractures
Vertebral body in spine can collapse of femur fracture under minimal force
Hypercalcaemia
Increased osteoclast activity
Plasmacytomas
Individual tumours formed by cancerous plasma cells
Occur in bones replacing normal bone tissue or in soft tissues
Why do patients with myeloma often develop renal impairment?
Paraproteins
Deposited in kidneys
Hypercalcaemia
Dehydration
Glomerulonephritis
Medications
Used to treat condition
What is the normal plasma viscosity vs water?
1.3-1.7 x
When does plasma viscosity increase?
More proteins in blood e.g. paraproteins in myeloma
Why is hyperviscosity syndrome an emergency?
Causes many issues
- Bleeding (nosebleeds and gums)
- Visual symptoms and eye changes (retinal haemorrhages)
- Neurological complication (stroke)
- Heart failure
What are the risk factors of myeloma?
Older age
Male
Black
Family history
Obesity
What are the presenting features of myeloma?
Persistent bone pain (spinal pain)
Pathological fractures
Unexplained fatigue
Unexplained weight loss
Fever of uknown origin
Hypercalaemia
Anaemia
Renal impairment
What investigations are used for myeloma?
FBC - anaemia or leukopenia
Calcium - raised
ESR - raised
Plasma viscosity - raised
U&Es - renal impairment
Serum-free light-chain assay - detect abnormally abundant light chains
BENCE JONES NO LONGER USED AT ALL
What is required to confirm diagnosis of myeloma?
Bone marrow biopsy required for diagnosis and perform cytogenic testing
What imaging is used to assess for bone lesions in myeloma?
Whole body MRI
Whole-body low-dose CT
Skeletal survey
What are the typical x-ray changes in myeloma?
Well-defined lytic lesions (punched out)
Diffuse osteopenia
Abnormal fractures
Raindrop skull or pepper pot skull, multiple lytic lesions in skull on xray
How is myeloma managed?
Oncology and haematology MDT
Aim is to control disease, never fully cured, relapsing-remitting course
How is myeloma treated?
Combination of chemotherapy
- Bortezomib (proteasome inhibitor)
- Thalidomide
- Dexamethasone
High-dose chemotherapy followed by stem cell transplant option for fitter patients, longer remission stem cell transplant can be
- Autologous (own stem cells)
- Allogenic (healthy donor)
How is myeloma bone disease managed?
Bisphosphonates - to suppress osteoclast activity
Radiotherapy - bone lesions can improve bone pain
Orthopaedic surgery - stabilise bones or treat fractures
Cement augmentation - injecting cement into fractures or lesions to improve spine stability or pain
What are the complications of myeloma?
Infection
Bone pain
Fractures
Renal failure
Anaemia
Hypercalcaemia
Peripheral neuropathy
Spinal cord compression
Hyperviscosity syndrome
VTE
What chromosomal translocation is associated with myeloma?
T(11:14)
What is Waldenström macroglobulinemia?
Disorder with high monoclonal IgM protein presence
Presents with:
- Fatigue
- Lymphadenopathy
- Hepatosplenomegaly
- Neuropathy
IgM is a pentamere and much bigger than other immunoglobulins, so much more viscous blood
How can you differentiate between myeloma and autoimmune disease using paraproteins?
Autoimmune causes a polyclonal rise
Myeloma causes a monoclonal rise
