myeloproliferative disorders Flashcards
(22 cards)
what are the three myeloproliferative disorders ?
polycythemia vera
essential thrombocythemia
myelofibrosis
CML
what are the gene disorders associated with each type of myeloproliferative disorder ?
CML - t 9;22 BCR ABL
polycythemia vera - JAk2
essential thrombocytosis - JAK 2
myelofibrosis - JAK 2
where is JAK 2 found and what does a mutation result in?
chromosome 9 , tyrosine kinase enzyme where there is hypersensitivity to cytokines
what are the lab findings associated with polycythemia vera ?
elevated red blood cell mass
low EPO levels ( if its high then EPO is high)
what are the 2 classic causes associated with PV and high EPO levels ?
either an EPO secreting tumor - RCC, HCC
or hypoxia in lung disease
this is called secondary polycythemia
can also be due to exogenous causes as seen with cyclists
what are the classic symptoms associated with PV ?
aquagenic pruritus
deep vein thrombosis - classically budd chiari
what is the treatment for PV ?
phlebotomy
hydroxyurea
what are the hematological disorders associated with Budd chiari syndrome ?
polycythemia vera
PNH
what is the mechanism of hydroxyurea ?
inhibits ribonucleatide synthase , blocks the formation of deoxynucleotides for DNA
what are the complications associated with PV?
spent phase - progression to myelofibrosis
leukemia usually AML
gout due to increased purine metabolism
what is essential thrombocythemia ?
malignant proliferation of myeloid cells
affecting the platelets - megakaryocytes
what is the JAK 2 inhibitor used ?
ruxolitinib
what is the usual case scenario associated with essential thrombocythemia ?
patients with raynauds , and a really rally high number of platelets associated with bleeding and thrombosis
what is the treatment for essential thrombocytosis ?
only high risk patients are treated with hydroxyurea aspirin and platelpheresis
what is the usual presentation associated with RT ?
a patient i=with infective endocarditis who now has a very high level of platelets
what is the BM pathology associated with primary myelofibrosis ?
excess collagen formation from fibroblasts
both PDGF and TGF B stimulate the megakaryocytes
what is the clinical presentation associated with myelofibrosis ?
massive splenomegaly , due to extramedullary hematopoeisis , dry tap on BM biopsy
leukoerythroblastosis
what is the treatment for primary myelofibrosis ?
stem cell transplant
what is seen on BM biopsy ?
tear drop cells poikilocytes
what is langerhans cell histocytosis ?
proliferation of dendritic langerhans cells especially in the bones hence the lytic lesions
what is seen on biopsy and microscopy of LCH ?
tennis raquet shaped granules and birbeck granules
s-100 positive and CD1a
horseshoe or kidney shaped nucleus
what is the most severe form of LCH ?
letterer siwe disease - occurs in babies
