Leukaemia Flashcards
Where does haematopoesis occur in the bone marrow?
in the red marrow
What is the pathogenesis of leukaemia?
mutations happen in the precursor cells that give them a survival advantage and they can hide from our immune system
these cells replicate unregulated and take over the bone marrow = clonal expansion of blast (immature cells) - these blasts cells should be in very small numbers in the bone marrow and not present at all in the peripheral blood, but in leukaemia, these cells fill the bone marrow and the blood
this results in bone marrow failure due to accumulation of blasts
What is the difference between the acute and chronic leukaemias?
the acute leukaemias come on very quickly and the problem is with the more immature cells eg stem cells (haemoblast) and common myeloid and common lymphoid progenitors
Chronic leukaemias come on slower and are a clonal expansion of the more mature cells
Which cells are affected in chronic myeloid leukaemia?
clonal expansion of basophils, neutrophils and eosinophils
Which cells are affected in chronic lymphocytic leukaemia?
mature lymphocytes eg B cells and T cells
Which cells are affected in acute lymphoblastic leukaemia?
lymphoblasts - the precursors of T and B cells
Which cells are affected in Acute myeloid leukaemia?
myeloblasts (the precursors of basophils, neutrophils, eosinophils and monocytes)
What are the risk factors for leukaemia?
Congenital eg germline mutations giving genetic predisposition
Down’s syndrome and AML
environmental: radiotherapy, chemo, benzene and other chemicals
What are the signs and symptoms of leukaemia?
anaemia: SOB, fatigue
thrombocytopenia: bruising, mucosal bleeding, rash - purpura and petechiae (non-blanching)
splenomegaly
infection: fevers/rigors
in leukaemia, these symptoms come on very quickly
infiltrations of the skin and other organs
gum hypertrophy
sometimes: SVCO, 3rd CN palsy
What investigations are done for leukaemia?
a) FBC
b) coagulation screen - present with coagulopathy eg in DIC + can bleed
c) biochem: U+E, LFT, Calcium, LDH, uric acid, B12, folate - to check liver and kidney function
d) group and screen
e) virology - HIV, Hep B, Hep C
f) CXR - as can get a large mediastinal mass
g) flow cytometry -to identify cell surface markers
h) cytogenetic analysis - identifies abnormal genetic changes and helps in prognosis
i) bone marrow biopsy -
What is the most common age range for ALL?
it is the commonest malignancy of childhood
median age is 3.5 years
What is the peak age of incidence of AML?
70 years old
What are the histological feature of myeloblasts?
Auer rods in the cytoplasm
Give examples of supportive means of treating a pt?
a) fluids
b) bone marrow support - blood and platelets
c) infection prevention and treatment: prophylactic antifungals, prophylactic antibiotics
d) treat the symptoms of treatment eg mucositis, diarrhoea, constipation, nausea, vomiting
e) pain relief
f) holistic care: psychological and emotional, relatives
What is the opposite of supportive treatment?
definitive treatment
