Myeloproliferative Disorders

Question 1

4 Myeloproliferative Disorders

Answer 1

1. CML
2. Polycythemia vera
3. Essential Thrombocythemia
4. Myelofibrosis

Question 2

CML

Answer 2

chronic myeloid leukemia
t(9;22) –> BCR-ABL, Ph chromosome
increase tyrosine kinase activity –> overgrowth
splenomegaly –> expanded red pulp
Transformation to acute leukemia –> AML or ALL
LAP(-)

Question 3

Polycythemia vera

Answer 3

mature myeloid cells, esp RBCs
increased granulocytes and platelets
Ax w/ JAK2 Kinase mutation
Hyperviscosity
Tx: blood letting; hydroxyurea --> hyperuricemia ; gout

Question 4

Essential Thrombocythemia

Answer 4

Neoplastic prolif of mature myeloid cells, esp platelets
Increased RBC and granulocytes
Ax w/ JAK2 kinase mutation + MPL tyrosine kinase
Dx of exclusion
thromboses erythromelalgia
no risk for gout

Question 5

Myelofibrosis

Answer 5

extensive collagen deposition by non-neoplastic fibrosis
esp megakaryocytes
Ax w/ JAK2 kinase mutation + MPL
produce excess PDGF –> marrow fibrosis, myelofibrosis
splenomegaly d/t extramedullary hematopoiesis
bone marrow contains–> reticulin gates
Leukoerythroblastic smear: cells can’t leave spleen, see nucleated RBCs
Tear drop cells