Haem + onc Flashcards
Which organisms most commonly cause neutropenic sepsis?
Coagulase -ve gram +ve bacteria
particularly staph epidermis
What are auer rods? what conditions are they seen in?
Large, pink / red needle shaped structures in cytoplasm of myeloid cells
Seen in AML
Also in APML, high grade myelodysplastic syndromes and myeloproliferative disorders
What are some features of APML?
Presents younger than other forms of AML (avg 25yrs)
DIC / Thrombocytopaenia at presentation
Good prognosis
Genetic cause of APML
t(15;17) translocation - fusion of PML and RAR-alpha genes –> blocks the maturation of myeloid cells and leads to an accumulation of promyelocytes.
APML mx?
Treated with all-trans retinoic acid (ATRA) -> forces immature granulocytes into maturation to resolve blast criseses prior to definitive chemo
Bloods in DIC? Blood film?
↓ platelets
↓ fibrinogen
↑ PT & APTT
↑ fibrinogen degradation products
schistocytes due to microangiopathic haemolytic anaemia
How can you distinguish between Waldenstrom’s macroglobulinaemia and multiple myeloma?
Waldenstrom’s macroglobulinaemia - Organomegaly with no bone lesions
Multiple myeloma - Bone lesions with no organomegaly
What are some features of Waldenstroms macroglobulinaemia?
Mx?
systemic upset: weight loss, lethargy
hyperviscosity syndrome e.g. visual disturbance (the pentameric configuration of IgM increases serum viscosity)
hepatosplenomegaly
lymphadenopathy
cryoglobulinaemia e.g. Raynaud’s
Mx - rituximab based combination chemo
Ix findings for waldenstrom’s macroglobulinaemia?
Monoclonal IgM paraproteinaemia (M - Macroglobulinaemia)
BM biopsy - diagnostic - infiltration of BM with lymphoplasmacytoid lymphoma cells
What genetic abnormality is associated with chronic myeloid leukaemia (CML)?
Philidelphia chromosome - t(9;22)
seen in 95% of cases
NB also seen in 25% of adults with ALL - poor prognostic feature in these cases
What genetic abnormality is seen in Burkitt’s lymphoma?
t (8;14) seen in Burkitt’s lymphoma
MYC oncogene is translocated to an immunoglobulin gene
What genetic abnormality is seen in Mantle cell lymphoma?
t(11;14) is seen in mantle cell lymphoma
deregulation of BCL-1 gene
What genetic abnormality is seen follicular lymphoma?
t(14;18) - increased BCL-2 transcription
What are some intravascular causes of haemolytic anaemia?
mismatched blood transfusion
G6PD deficiency*
red cell fragmentation: heart valves, TTP, DIC, HUS
paroxysmal nocturnal haemoglobinuria
cold autoimmune haemolytic anaemia
Extravascular causes of haemolysis
haemoglobinopathies: sickle cell, thalassaemia
hereditary spherocytosis
haemolytic disease of newborn
warm autoimmune haemolytic anaemia
What does haptoglobin do?
Binds to free Hb which is released in intravascular haemolysis - hence depleted in intravascular causes
What happens to free Hb once haptoglobin is saturated? how is this detected?
As haptoglobin becomes saturated haemoglobin binds to albumin forming methaemalbumin (detected by Schumm’s test).
Bloods in Warfarin?
PT - Prolonged
APTT - Normal
Bleeding time - Normal
Plts - Normal
Bloods in Aspirin use?
Bleeding time - prolonged
PT - Normal
APTT - Normal
Plts - Normal
Bloods in heparin use?
APTT - Prolonged
PT - Normal (usually) / prolonged
Bleeding time - normal
Plts - Normal
How does ITP present?
Commonly in older females - isolated thrombocytopaenia usually incidentally on bloods
If sx:
- petechiae, purpura, bleeding (epistaxis) -> catastrophic bleeding is not common
What is Evans syndrome?
When ITP is associated with AIHA
How can you distinguish between Ig in Cold and Warm AIHA?
Warm = Greece IgG
Cold = Moscow IgM
What can be seen in blood film in hereditary spherocytosis post surgery and why?
Howell-Jolly bodies - these are remnants of RBC nucleus normally removed by spleen
Hence visible post splenectomy