Flashcards in MYELODYPLASTIC SYNDROME Deck (15):
What is myelodysplastic syndrome?
Clonal haemopoietic disorders characterised by ineffective haemopoiesis resulting in peripheral blood cytopenia (especially anaemia). There is an increased risk of developing acute leukaemia.
What age group is most commonly affected by myelodysplastic syndrome?
Elderly - 60-75 but it does affect younger people as well
Are the majority of cases of myelodysplastic syndrome primary or secondary?
What are the causes of secondary myelodysplastic syndrome?
Exposure to occupational chemicals especially benzene
Previous high dose chemotherapy (eg before bone marrow transplant) or radiotherapy
How do secondary therapy related cases of myelodysplastic syndrome compare to cases of primary myelodysplastic syndrome?
Therapy related MDS involves:
More severe cytopenia
Occurrence at younger age
A higher rate of transformation into acute leukaemias
More clonal chromosomal abnormalities
A generally poorer prognosis
What is the pathogenesis of myelodysplastic syndrome?
DNA damage of a pluripotent stem cell leads to development of myelodyplastic clone which has a growth advantage. Increased cellular proliferation within bone marrow results in hypercellular marrow. However, these cells do not differentiate properly and there is increased rate of apoptosis. Therefore, fewer mature cells leave the bone marrow, resulting cytopenia.
How might someone with myelodysplastic syndrome present?
Often asymptomatic and found on incedental FBC
Signs and symptoms of pan-cytopenia: fatigue, shortness of breath, bleeding, infection
What investigations should be ordered for someone with suspected myelodysplastic syndrome?
Bone marrow aspirate and trephine biopsy
Cytogenetics - presence of same cytogenic abnormality in multiple cells in the marrow
What are the changes seen on a blood film of someone with myelodysplastic syndrome?
Anisocytosis (abnormal size)
Poikilocytosis (abnormal shape)
Unusual nuclear shape
What are the three main types of myelodysplastic syndrome?
Refractory anaemia with ringed sideroblasts
Refractory anaemia with excess blasts
What are the changes that might be seen on bone marrow biopsy from someone with myelodysplastic syndrome?
Megakaryocytes with separated nuclei
What is the prognosis of someone diagnosed with myelodysplastic syndrome?
6 months to 6 years
How are myelodysplatic syndrome patients managed?
Supportive transfusions of red cells and platelets
EPO injections may reduce number of transfusions needed - particularly useful in refractory anaemia with ringed sideroblasts
Immunosuppressives such as ciclosporins or antithymocyte globulins
Allogeneic stem cell transplant
What is the genetic abnormality associated with myelodysplastic syndrome in middle aged woman which is associated with a longer survival and a lower risk of transformation into acute myeloid leukaemia?
Loss of the long arm of chromosome 5