MYELOMA + some extra cheeky diseases Flashcards
what is myeloma?
Cancer of the plasma cells causing them to produce paraproteins (monoclonal antibodies)
presentation of myeloma?
CRAB
-hypercalcaemia
-renal impairement
-anaemia
-bone pain
why does myeloma cause renal impairement?
Para proteins cause cast nephropathy- clog up kidney filtration system
why is there hypercalcaemia in myeloma?
-due to increase of osteoclast activity and surpressed osteoblast activity (more bone being broken down than being made)
-increase in osteoclast activity causes a lot of calcium to be absorbed from the bone into blood increasing calcium
what occurs to plasma viscosity and why- myeloma?
-plasma viscosity increase when there are more proteins in blood (paraprotein)
how is myeloma classified and give some examples
Classified by type of antibody produced:
-IgG (most common)
-Bence jones myeloma
-IgA
-IgE
-Biclonal
what type of antibody increases plasma viscosity the most and why?
IgM
-because its a pentamere!
(associated with WALDENSTROM MACROGLOBULINAEMIA)
top 3 most common types of myeloma?
-IgG (most common)
-IgA (2nd)
-Bence jones myeloma (free light chain)
what are antibodies made up of?
2 heavy chains and 2 light chains
blood film of someone with myeloma?
rouleaux formation (stacking of RBC)
what can be found in urine of someone with certain type of myeloma?
BENCE JONES PROTEINS
Imagine of choice for myeloma?
full body MRI!
-will allow you to assess bone lesions (so lytic!)
X-ray findings on myeloma?
-punched out lesions
-lytic lesions
usual management of myeloma?
usually patients quite old so less aggressive treatment= combination chemotherapy
management of myeloma in young/ fit patients?
high dose chemo/ autologous stem cell transplant
what is used to manage hypercalcaemia + bone pain?
biphosphonates
what is used to fix fractures bones e.g. vertebrae?
Vertebroplasty
- inject sterile cement into fractured bone to stabilise
what is MGUS?
-benign myeloma precursor
-when there is an excess of a single type of antibody or antibody components without other features of myeloma or cancer
how likely are you to get myeloma with MGUS?
-slightly increased risk of developing myeloma (increased by 1% every year)
most people actually die of old age not myeloma
findings- MGUS? (monoglonal gammopathy of undertermined significance)
Paraprotein <30g/l
Bone marrow plasma cells <10%
No evidence of myeloma end organ damage:
-normal calcium
-normal renal function
-normal haemoglobin
-no lytic lesions
-no increase in infections
what is AL amyloidosis?
Rare, benign disorder that is similar to MGUS
-There is a mutation in the light chains of the antibodies produced by the plasma cells, this alters their structure so they are insoluble beta pleated sheets
-these insoluble beta sheets/ amyloid cause end organ damage
how does AL amyloidosis present?
Most commonly= weakness and dyspnoea
Depends what organ is effected
(2/3rds) Kidney involvement:
-nephrotic syndrome
(1/2) Heart involvement:
-Cardiomyopathy
BUZZ WORDY INVESTIGATION!! to confirm AL amyloidosis
Gold standard =
Organ biopsy
+
Congo red staining- will show ‘Apple green’ birefringement under polarised light
what type of biopsy can be done that is less invasive for AL amyloidosis?
rectal or fat biopsy
