MPD and MDS

Question 1

What are the myeloproliferative disorders?

Answer 1

Polycythemia vera, Essential thrombocytosis, Primary myelofibrosis, Chronic myeloid leukemia

Question 2

What is a myeloproliferative disorder?

Answer 2

A group of bone marrow disorders that are characterized by an acquired overproduction of mature myeloid blood cells d/t malignant hematopoietic stem cell of the myeloid cell lineage

Question 3

Causes of myeloproliferative disorders?

Answer 3

Not clearly understood, acquired gene mutations affecting precursor cell in bone marrow

Question 4

Common features of myeloproliferative disorders?

Answer 4

Considered dx of exclusion (r/o other causes that can cause increase in cell lineages first), characterize by dysregulation of particular lineage of mature myeloid cells w/ fairly normal differentiation, exhibit variable tendency to transform to other MPDs or acute leukemia

Question 5

What is polycythemia vera (aka primary erythrocytosis)?

Answer 5

Acquired progressive malignant d/o of the bone marrow, resulting in an increase of all 3 myeloid cell lines *but esp RBCs
(elevated RBC, WBC, PLT)

Question 6

Who is polycythemia vera most common in?

Answer 6

M>F, median age presentation at 60 but can happen in all age groups

Question 7

What is the most common myeloproliferative neoplasm?

Answer 7

Polycythemia vera

Question 8

Cause of primary polycythemia vera?

Answer 8

Acquired genetic mutations (JAK2 in 95% - gain of function/mutation always on)
*NOT driven by EPO

Question 9

With secondary polycythemia vera, what causes must be ruled out?

Answer 9

Chronic hypoxia (high altitude, cardiac disease, pulmonary disease), Renal tumors (increased EPO), Dehydration (dec. plasma volume)

Question 10

Clinical presentation of polycythemia vera?

Answer 10

May be asx and detected on routine CBC
-Hyperviscosity sx: Headache, dizzy, confusion, visual impairment (retinal vein engorgement), dyspnea, thrombi
-Generalized pruritis after hot shower

Question 11

PE for polycythemia vera?

Answer 11

Plethora (ruddy face/palms), splenomegaly, engorged retinal veins, elevated HTN, erythromelalgia (intense redness/warmth/pain on palms and soles from small blood clots in distal extremities)

Question 12

Risk for what with polycythemia vera?

Answer 12

Thrombosis (thick blood, high PLT count, slow circulation) and Gout (purines broken down from inc. RBCs –> uric acid)

Question 13

Diagnostics for polycythemia vera?

Answer 13

-CBC: elevated RBC, PLT, WBC (increased eosinophils, basophils)
-EPO: LOW (body suppresses d/t so many RBCs, helps distinguish between secondary causes of inc. RBCs)
-Bone marrow bx: Hypercellular
-Flow cytometry: + for JAK-2 mutation

Question 14

WHO major criteria for polycythemia vera dx?

Answer 14

1. Hgb > 16.5 men, >16 women or HCT >49% men, >48% women or increased RBC mass
2. BM bx w/ hypercellularity for age w/ trilineage growth
3. presence of JAK2 V617F or JAK2 exon 12 mutation

Question 15

WHO minor criteria for polycythemia vera dx?

Answer 15

Subnormal serum EPO

Question 16

Diagnostic criteria for polycythemia vera?

Answer 16

Must have all 3 major criteria or first 2 major and the 1 minor

Question 17

Initial mainstay of tx for polycythemia vera?

Answer 17

Phlebotomy to HCT <45%, 1/wk then PRN to maintain HCT
+ ASA 81mg daily for all pts unless C/I