haematological malignancy Flashcards
epidemiology of haematological cancers
account for ~11% of all cancers
occur in all age groups, incl children
adult males are more commonly affected than females
what is the commonest group of blood cancers
non Hodgkin’s lymphoma
what age does non Hodgkins lymphoma occur at
disease of middle and older age - 40/50s, majority of pts in 60s/70s
can occur in children and young adults
M>F
what age does Hodgkins lymphoma occur at
peak incidence between 18 and 35 and then again 60-80s
5-6/100 000 p/a
M>F except in younger people where F>M
pathogenesis of haematological malignancies
multi-step process
acquired genetic alterations in a long lived cell (e.g. stem cell)
proliferative/survival advantage to that mutated cell –> produces a malignant clone –> grows to dominate the tissue
where are multipotentential haematopoietic stem cells found
bone marrow
born with a fixed amount of these cells and we keep them throughout our life
special characteristics of multipotentential haematopoietic stem cells
when they divide they have the ability to self-renew - when the cell divides, one of the two daughter cells is retained
ability to give rise to every single cellular blood product (pluripotent)
growth of a malignant clone of cells in the development of leukaemia
genetic mutation in haematopoietic stem cells
clone of mutated cell - asymptomatic to begin with
additional mutations occur and clones continue
disease takes off, growth advantage and dominates normal cells
lineage of bone marrow malignancies
myeloid:
red cells, platelets, granulocytes, monocytes
lymphoid:
B and T cell
what happens to the cells in acute myeloid leukaemia
mutational events lead to growth advantage so daughter cells of stem cells can proliferate
differentiation is blocked so they grow but they can’t ‘grow up’ - remain as immature, useless cells (blast cells)
what condition is this
acute leukaemia
blocking the bone marrow
what happens to the cells in myeloproliferative disorders e.g. chronic myeloid leukaemia
growth advantage AND ability to differentiate
accumulate more useful cells than you need
what condition is this
chronic myeloid leukaemia
what happens to the growth of cells in acute lymphoblastic leukaemia
mutations in the stem cell population
proliferation but block mutation
what condition is this
acute lymphoblastic leukaemia
what can be seen here
bone marrow in multiple myeloma showing plasmacytosis - lots of protein production in the cells, eccentric nu and marked Golgi zone (plasma cells therefore increased antibody production)
multiple myeloma - malignancy of plasma cells
leukaemia vs lymphoma
descriptive terms that describe the distribution of the disease in the body
disease predominantly in blood and bone marrow –> leukaemia
predominantly in LNs or other organs –> lymphoma
structure of the lymph node
medulla - where the lymphatic channels and blood vessels come into
germinal centres - where B cells grow up after release from bone marrow, exposed to antigens in LNs
B cell maturation
lympocytes are released from bone marrow and then go into the germinal centre of LN
here they are exposed to antigens by APCs
B cell can then present immunoglobulin to bind the antigen and attack it
if it does this successfully it emerges from the germinal centre; if not the cells are deprived of survival factors and die
