Chronic myeloproliferative disorders

Question 1

Polycythemia Vera

Answer 1

Abnormal clone of hematopoetic stem cells with constituitively active JAK2 receptors, proliferative w/o EPO stimulation; often presents as intense itching after hot shower

Increased RBCs, Increased WBCs, Increased platelets; JAK2 mutation positive

Question 2

Essential thrombocytosis

Answer 2

Specific for megakaryocytes

Increased platelets; Positive JAK2 mutation in 30-50%

Question 3

Myelofibrosis

Answer 3

Fibrotic obliteration of bone marrow; teardrop cell

Decreased RBCs, variable WBCs, Variable platelets; positive JAK2 mutation in 30-50%

Question 4

CML

Answer 4

Decreased RBCs, Increased
bcr-abl transformation leads to increased cell division and inhibition of apoptosis

WBCs, Increased platelets; positive philadelphia chromosome; negative JAK2 mutation