Myeloproliferative Disorders

Question 1

complications common to all myeloproliferative disorders

Answer 1

hyperuricemia/gout (purine degradation)
bone marrow fibrosis
acute leukemia

Question 2

neoplastic proliferation of mature myeloid cells, esp granulocytes

Answer 2

CML

Question 3

what type of cell is characteristically increased in CML?

Answer 3

basophils

Question 4

chromosomal abnormality that drives CML

Answer 4

t(9;22)

Question 5

what is the consequence of the t(9;22)

Answer 5

BCR-ABL fusion protein –> increased tyrosine kinase activity (signal transducer)

Question 6

first line of treatment for CML

Answer 6

imatinib (blocks tyrosine kinase activity)

Question 7

marker of accelerated phase of CML, leading to transformation of acute leukemia

Answer 7

enlarging spleen

Question 8

what is the worst possible complication of CML

Answer 8

transformation to AML or ALL (because mutation is in the hematopoietic stem cell)

Question 9

3 characteristics of CML that can be used to distinguish it from leukemoid reaction (infection)

Answer 9

1. LAP negative (LAP is used to fight infection)
2. basophils
3. t(9;22)

Question 10

neoplastic proliferation of mature myeloid cells, esp RBCs

Answer 10

polycythemia vera (PV)

Question 11

mutation associated with polycythemia vera

Answer 11

JAK2 kinase

Question 12

myeloproliferative disorder that presents with blurry vision, headache, flushed face, itching after bathing

Answer 12

polycythemia vera

Question 13

treatment for polycythemia vera

Answer 13

phlebotomy

second line: hydroxyuria

Question 14

features that distinguish PV from a reactive polycythemia

Answer 14

1. normal SaO2

2. decreased EPO (negative feedback)

Question 15

neoplastic proliferation of mature myeloid cells, esp platelets

Answer 15

essential thrombocytopenia

Question 16

mutation associated with essential thrombocytopenia

Answer 16

JAK2 kinase

Question 17

myeloproliferative d/o that rarely progresses to marrow fibrosis or progresses to acute leukemia and no increased risk for hyperuricemia

Answer 17

essential thrombocytopenia

Question 18

neoplastic proliferation of mature myeloid cells, esp megakaryocytes

Answer 18

myelofibrosis

Question 19

mutation associated with myelofibrosis

Answer 19

JAK-2 kinase

Question 20

mechanism that produces marrow fibrosis in myelofibrosis

Answer 20

megakaryocytes produce excess PDGF

Question 21

mechanism of splenomegaly in myelofibrosis

Answer 21

extramedullary hematopoiesis - fetal hematopoietic stem cells were located in spleen

Question 22

blood smear resulting from extramedullary hematopoiesis in myelofibrosis

Answer 22

leukoerythroblastic smear

Question 23

tear drop cell

Answer 23

myelofibrosis (from RBCs produced in fibrotic bone marrow)