Primary myelofibrosis vs Aplastic anemia
How to tell Primary myelofibrosis and Aplastic anemia apart when a board question makes them look alike.
Myelofibrosis is scarred marrow with teardrops and big spleen; aplastic anemia is empty marrow without extramedullary hematopoiesis.
Side by side
Primary myelofibrosis is clonal myeloproliferation with marrow fibrosis, dry tap, teardrop RBCs, leukoerythroblastosis, massive splenomegaly, and extramedullary hematopoiesis.
Aplastic anemia is hypocellular fatty marrow with pancytopenia, low reticulocytes, no splenomegaly, and no teardrop leukoerythroblastic picture.
Abnormal megakaryocytes release fibrogenic cytokines that scar marrow and push hematopoiesis to spleen and liver.
Stem cell failure leaves marrow unable to produce blood cells, often immune mediated or toxin/drug/radiation related.
Dry tap, marrow fibrosis on biopsy, teardrop cells, nucleated RBCs, immature granulocytes, high LDH, and JAK2/CALR/MPL mutations support primary myelofibrosis.
Hypocellular fatty marrow, pancytopenia, low reticulocyte count, and absence of infiltrative smear findings support aplastic anemia.
The trap
Both can cause pancytopenia, but teardrop cells, splenomegaly, and dry tap point to fibrosis rather than aplasia.
Watch it explained
The repair move
For pancytopenia with marrow failure, decide whether the marrow is empty or fibrotic and displaced to the spleen.
Try a free question
CoreA patient has fatigue, early satiety, massive splenomegaly, teardrop RBCs, nucleated RBCs, immature granulocytes, dry tap on aspiration, and marrow fibrosis on biopsy. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Primary myelofibrosis. Dry tap, teardrop cells, leukoerythroblastosis, and massive splenomegaly point to primary myelofibrosis.
Why the other choices are tempting
- B. Aplastic anemia has hypocellular fatty marrow without splenomegaly or teardrop leukoerythroblastosis.
- C. Iron deficiency anemia causes microcytosis, not dry tap fibrosis.
- D. CLL causes mature lymphocytosis and smudge cells.
- E. Reactive thrombocytosis does not cause marrow fibrosis with dry tap.
Flashcards
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What smear clue points to primary myelofibrosis?
Teardrop RBCs with a leukoerythroblastic smear point to primary myelofibrosis.
What aspiration clue points to primary myelofibrosis?
A dry tap points to marrow fibrosis in primary myelofibrosis.
Quick answers
What is the fastest way to tell Primary myelofibrosis from Aplastic anemia?
Myelofibrosis is scarred marrow with teardrops and big spleen; aplastic anemia is empty marrow without extramedullary hematopoiesis.
What is the key clue for Primary myelofibrosis?
Primary myelofibrosis is clonal myeloproliferation with marrow fibrosis, dry tap, teardrop RBCs, leukoerythroblastosis, massive splenomegaly, and extramedullary hematopoiesis.
What is the key clue for Aplastic anemia?
Aplastic anemia is hypocellular fatty marrow with pancytopenia, low reticulocytes, no splenomegaly, and no teardrop leukoerythroblastic picture.
What is the common trap with Primary myelofibrosis vs Aplastic anemia?
Both can cause pancytopenia, but teardrop cells, splenomegaly, and dry tap point to fibrosis rather than aplasia.