prefibrotic stage of primary myelofibrosis

Synopsis

 bone marrow hyperplasia
 predominance of megakaryocytic and erythroid precursors is observed
 slight increase in reticulin staining
 more typical of (adult) agnogenic myeloid metaplasia with myelofibrosis

2001 criteria for prefibrotic PMF

 Clinical findings

• Spleen and liver
  • No or mild splenomegaly or hepatomegaly

• Hematology (variable)
  • Mild anemia
  • Mild to moderate leukocytosis
  • Mild to marked thrombocytosis

 Morphological findings

• Blood
  • No or mild leukoerythroblastosis
  • No or mild red blood cell poikilocytosis
  • Few if any dacryocytes

• Bone marrow
  • hypercellularity
  • neutrophilic hyperplasia (neutrophilic proliferation)
  • megakaryocytic proliferation (megakaryocytic proliferation)
  • megakaryocytic atypia
    • clustering of megakaryocytes
    • abnormally lobulated megakaryocytic nuclei
    • naked megakaryocytic nuclei.

• • Minimal or absent reticulin fibrosis

See also

 primary myelofibrosis

References

 Proposals and rationale for revision of the World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis: recommendations from an ad hoc international expert panel, Blood, 2007 (http://bloodjournal.hematologylibrary.org/content/110/4/1092.full)