Table of Contents
Definition / general | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Mihova D. Acute panmyelosis with myelofibrosis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/leukemiapanmyelosis.html. Accessed September 22nd, 2021.
Definition / general
- Also called acute (malignant) myelofibrosis, acute (malignant) myelosclerosis, acute myelodysplasia with myelofibrosis
- Now a distinct entity in WHO (2008) but not previously (Ann Hematol 2004;83:513, Leuk Lymphoma 2004;45:681)
- Rare, rapid onset, aggressive, usually adults
- Weakness, fatigue, fever, bone pain, pancytopenia; usually no marked splenomegaly
- Median survival is 2 - 9 months
Case reports
- Successful treatment with biphosphonates (Eur J Haematol 2004;73:215)
Microscopic (histologic) description
- Hypercellular marrow with erythroblasts, immature granulocytes, megakaryocytes
- Prominent megakaryocytic abnormalities with variation in size and dysplastic changes, immature granulocytes with dysplasia and immature erythrocytes
- Usually marked fibrosis (reticulin > collagen)
- Aspirate smear is often hypocellular due to marked fibrosis
Microscopic (histologic) images
Bone marrow smear (Wright-Giemsa):
Numerous blasts, some CD61+,
also abnormal erythroid
and granulocyte cells
Blasts and more mature granulocytes, also
a large megakaryocyte with a poorly lobulated
nucleus and dispersed chromatin, occasional
neutrophils and late stage erythroblasts
Bone marrow biopsy:
Partial replacement of marrow by
blasts and increased fibrous tissue
Numerous blasts with some clustering
Lymph node biopsy:
Total effacement by blasts, also
scattered megakaryocytes at
various stages of maturation
Blasts have fine chromatin and small but
distinct nucleoli, mitotic figures are present
Stains:
Increase in coarse reticulin fibers
Reticulin stain shows markedly
hypercellular marrow with proliferation
of blasts and maturing cells, and
increase in coarse reticulin fibers
Positive stains
- CD34 and HLA-DR (Leuk Lymphoma 2004;45:1873)
- Erythroblasts: glycophorin A, hemoglobin A
- Granulocytes: myeloperoxidase, CD13, CD33 and CD117
- Monocytes: lysozyme, CD68
- Megakaryocytes: CD31, CD41, CD61, PAS and factor VIII
Negative stains
- Usually CD42b (Mod Pathol 2005;18:603), von Willebrand factor
Differential diagnosis
- Acute megakaryoblastic leukemia: no prominent changes in granulocytes or erythroid cells
- Chronic idiopathic myelofibrosis: marked splenomegaly and prominent dysplasia
- Metastatic carcinoma with desmoplasia
- Myelodysplastic syndrome with myelofibrosis: lacks high percentage of blasts
