Flashcards in Myeloproliferative Disorders Deck (77)
What does 'myelo' refer to?
Bone marrow lineage(s) – granulocytes, red cells and platelets
What does proliferative refer to?
Ability to grow or multiply by rapidly producing new tissue parts, cells, or offspring
What are myeloproliferative disorders?
Clonal haeomatopoietic stem cell disorders
i.e expansion of a single cell type
How are myeloproliferative disorders different from acute leukaemia?
Clonal haemopoietic stem cell disorders with an increased production of one or more types of haemopoietic cells
In contrast with acute leukaemia, MATURATION of myeloproliferative disorders is _________
In acute leukaemia, there is a block of __________
What would histology of acute leukaemia look like?
Monoclonal - lots of primitive cells which look the same
What would histology of chronic myeloproliferative disorders be like?
Polyclonal - lots of different cell types
How can myeloproliferative disorders be broadly grouped?
As either BCR-ABL1 positive or BCR-ABL1 negative.
What MPD is BCR-ABL1 positive?
Chronic myeloid leukaemia
What does chronic myeloid leukaemia involve the overproduction of?
What is the genetic aetiology of BCR-ABL1 conditions?
The philidelphia chromosome
What 3 MPD's are BCR-ABL1 negative?
1. Essential thrombocytopenia
2. Polycythaemia ruba vera
3. Idiopathic myelofibrosis
What is overproduced in essential thrombocytopenia?
What is overproduced in polycythaemia ruba vera?
** When should you suspect a MPD in someone? **
High granulocyte count
High platelet count
High red cell count
* Thrombosis (in unusual places)
WITH NO EXPLANATION OF CAUSE
What should you always do if you get an unusual blood count?
Take another sample
What happens, pathologically, in chronic myeloid leukaemia?
Proliferation of myeloid cells.
* Granulocytes and their precursors.
* Other lineages (platelets).
In the past, what was the course of chronic myeloid leukaemia (CML) like?
Initial chronic phase with intact maturation for 3-5 years, followed by a ‘blast crisis’ reminiscent of acute leukaemia with maturation defect.
This was fatal without stem cell/bone marrow transplantation in the chronic phase.
What are the 3 phases of CML?
* Chronic phase.
* Accelerated phase.
* Blast crisis - loss of maturation
Describe the chronic phase.
Excess of mature neutrophils, with some visible precursors
Describe the accelerated phase.
Proportion of mature cells in the body is dropping relative to the amount of primitive cells
Describe the blast crisis.
Monomorphic, primitive cells
i.e loss of maturation
Outline the clinical features of CML.
* Splenomegaly – early satiety, palpable spleen.
* Hypermetabolic symptoms.
* Gout (due to high cell turnover)
* Problems related to hyperleukocytosis (sludging of blood in small vessels)
* Priapism (prolonged erection).
How can splenomegaly often present?
Palpable spleen OR early satiety - feeling full quicker because the large spleen is pressing on the stomach
What are the lab features in CML?
Blood count changes:
* Normal/decreased Hb.
* Neucocytosis with neutrophilia and myeloid precursors (myelocytes), eosinophilia, basophilia.
* Bone marrow changes
Basically - increased WBC, increased platelets, normal or low Hb
What high cell count is particularly indicative of CML?
Basophilia - not many conditions cause this
The higher the white count, the more likely you are to have microvascular complications.
** What is the genetic hallmark of CML? **
The Philadelphia chromosome – translocation between chromosomes 9 and 22; ABL and BCR genes fuse together