3. INTRODUCTION
WHO classification of chronic
myeloproliferative neoplasm:
Primary myelofibrosis
Essential thrombocytosis
Polycythemia vera
Mastocytosis
Myeloproliferative neoplasms,
unclassifiable
Chronic myeloid leukaemia,
bcr-abl (positive)
Chronic neutrophilic leukaemia
Chronic eosinophilic
leukaemia, NOS
4. ⢠Primary myelofibrosis (PMF), Secondary
Myelofibrosis (malignant/nonmalignant)
⢠Primary myelofibrosis (PMF) is least common,
affect men > female in 6th decades or later
⢠PMF: absence of specific clonal marker -difficult to
establish the diagnosis
⢠myelofibrosis + splenomegaly seen in polycythemia
vera and CML
5. DEFINITION
⢠AKA Chronic primary myelofibrosis / idiopathic myelofibrosis
/ agnogenic myeloid metaplasia / myelofibrosis with myeloid
metaplasia
âA clonal disorder of a multipotent hematopoietic
progenitor cell of unknown etiology characterized by marrow
fibrosis, extramedullary hematopoiesis and splenomegalyâ
6. ETIOLOGY
⢠PMF: unknown
nonrandom chromosome abnormalities (9p,20q-
,13q-,trisomy 8 or 9, or partial trisomy 1q)
JAK2 V617F in 50% patients
mutations in receptor Mpl in 5% patients
mutations in calreticulin gene (CALR) -alter
carboxy-terminal portion of the gene product
14. COMPLICATIONS
⢠Evolve to accelerated phase
⢠Marrow failure
⢠10% transform into aggressive acute leukaemia
15. ⢠Survival is less than in PV & ET (4 years after
diagnosed but range 1-20 years)
PROGNOSIS
16.
17.
18.
19. MANAGEMENTS
⢠no specific treatment
⢠Ruxolitinib (JAK2 inhibitor)
⢠HSCT for younger patients
⢠PCV transfusion, folic acid
⢠corticosteroid (for constitutional symptoms; fever,
chills, night sweats, anorexia, weight loss)
⢠low dose thalidomide * combine with prednisone
20. ⢠hydroxycarbamide (cytotoxic, to control spleen size)
⢠splenectomy
⢠erythropoietin/danazol (for anemia) *erythropoietin
can worsen splenomegaly if serum level is >125
mU/L
21. REFERENCES
⢠Davidsonâs Principles and Practicals of Medicine,
22nd Edition, page 1048-1049
⢠Harrisonâs Principles of Internal Medicine, 19th
Edition, page 674-676
⢠mayoclinic