primary myelofibrosis

Definition: Idiopathic myelofibrosis (IM), is a chronic myeloproliferative disorder (MPD) characterised by marrow fibrosis, extramedullary haematopoiesis and a leuco-erythroblastic picture of the peripheral blood.

Images

 megakaryocytic hyperplasia and bizarre megakaryocytes in clusters in primary myelofibrosis (PMF)

• https://twitter.com/mariaramir/status/731175925627400196
• https://twitter.com/ArchivesPath/status/831997678049452033
• https://twitter.com/pwraess/status/830576419046453248
• https://twitter.com/AlesitaRosell/status/875729008771690496

 Massive splenomegaly (4.1 kg) in a patient with primitive myelofibrosis (PMF). Classic intrasinusoidal EMH & atypical megakaryocytic proliferation.

• https://twitter.com/JeffreyVosMD/status/880246683006894080

 bone marrow: primary myelofibrosis, prefibrotic stage; JAK2 pos

• https://twitter.com/BellaMicheleang/status/776357892429676544

Digital slides

 UI:740 - Chronic idiopathic myelofibrosis.
 HPC:9669 (ICSFramework)
 HPC:283

Primary myelofibrosis is currently classified as a myeloproliferative disease in which the proliferation of an abnormal type of bone marrow stem cell results in fibrosis, or the replacement of the marrow with collagenous connective tissue fibers

Types

 prefibrotic stage of primary myelofibrosis

• 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

 fibrotic stage of primary myelofibrosis

• increased silver (reticulin) staining
• marked fibrosis with pockets of cellularity that have fibroblasts and atypical megakaryoblasts

Cytogenetics

 trisomy 1q
 del(13q)
 del(20q)
 trisomy 8
 t(6;10) (q27;q11) (11248333)

Associations

 multiple myeloma (7644355)

See also

 bone marrow fibrosis
 myelofibrosis
 bone marrow anomalies
 bone marrow diseases
 bone marrow lesions
 megakaryocytes

• megakaryocytic anomalies

 essential thrombocythemia

References

 Cox MC, Panetta P, Venditti A, Abruzzese E, Del Poeta G, Cantonetti M, Amadori S. New reciprocal translocation t(6;10) (q27;q11) associated with idiopathic myelofibrosis and eosinophilia. Leuk Res. 2001 Apr;25(4):349-51. PMID: 11248333