Primary Myelofibrosis (PMF) Flashcards
Clinical presentation of primary myelofibrosis
asymptomatic,
severe fatigue,
non specific symptoms (fever, weight loss)
hepatosplenomegaly due to extramedullary hematopoiesis
Lab findings in primary myelofibrosis?
normocytic anemia with tear drop cells
initially see leukocytosis >30K followed by leukopenia
initially see thrombocytosis >500 followed by thrombocytopenia
bone marrow aspirate is dry tap and bone marrow biopsy with fibrosis
Diagnosis is by:
bone marrow biopsy/aspirate is dry tap and bone marrow biopsy with fibrosis
Primary myelofibrosis is a chronic myeloproliferative disorder caused by (explain the pathophysiology)
overproduction of megakaryocytes and bone marrow stromal cells which release fibrosis promoting cytokines into bone marrow.
See initially leukocytosis and thrombocytosis and then they develop morocytic anemia, leukopenia and thrombocytopenia as bone marrow is filled with fibrosis
What do you see on peripheral smear?
tear drop shaped cells as RBCs squeeze out the spleen. See extramedullary hematopoeisis
see dysmorphic erythrocytes, immature granulocytes (myelocytes and metamyelocytes and blasts).
Would need to get a bone marrow biopsy to confirm marrow fibrosis -see dry tap
Name this condition. Pt has massive hepatosplenomeagly.
primary myelofibrosis
JAK2 (janus kinase 2) mutation is associated with these conditions:
polycythemia vera,
essential thrombocytosis
primary myelofibrosis.
Not seen with CML.
pt who has a long history of polycythemia vera presents with anemia, need for phlebotomy and massive splenomegaly and has low platelets could have
post polycythemia vera myelofibrosis
Polycythemia vera pts are at greater risk for developing
thrombotic events (VTE, stroke, MI)
post PV myelofibrosis - generally happens 5-10 years post PV diagnosis.
acute myeloid leukemia
myelodysplastic syndrome
treatment of post PV myelofibrosis is
allogenic hematopoietic stem cell transplantation
with seere splenomegaly and debilitating constitutional symptoms can be treated with JAK2 inhibitors (ruxolitinib)
Risk factors for primary myelofibrosis?
seen in 50-60yrs
history of exposure to toluene, benzene or high levels of radiation.
Thorotrast - out of date contrast.
Is myelofibrosis the same thing as a myelodysplastic syndrome?
NO. THEY ARE NOT THE SAME THING.
Myelodysplastic syndrome - crappy bone marrow makes crappy blood cell lines which don’t function well. leads to cytopenias and symptomatic anemia, neutropenia, thrombocytopenia
Myelofibrosis - type of myeloproliferative disorder - bone marrow has RAPID PROLIFERATION - They are named by the proliferating line.
With myelofibrosis - PROLIFERATION of clonal megakaryocytes which secrete excess fibroblast growth factor which leads to more of fibrosis over time.
see bone marrow biopsy - dry tap with no aspirate because the bone marrow is fibrosed down.
see extramedullary hematopoeisis because the bone marrow is filled with fibrosis or scar from the excessive fibroblast production.
Treatment of primary myelofibrosis is with
allogeneic hematopoietic stem cell transplant.
based on HLA matched donor and who are healthy enough to survive the procedure and have poorp prognostic features including older age, constitutional symptoms, more severe anemia or thrombocytopenia.
who gets ruxolitinib?
this is treatment for primary myelofibrosis if they don’t qualify for hematopoietic stem cell transplant
does not alter progression to AML
helps improve the splenomegaly and hypercatabolic symptoms.
when do we do splenectomy for primary myelofibrosis? why do we not like this?
only remove if it’s massive and causing debilitating symptoms
don’t like it because this was making blood cells for body. removing it can cause significant morbidity and mortality.
