過形成髄と線維化のない, あるいは軽度弾性線維増生のみられる最初のprefibrotic/ early stageから段階的に進行する. 最終的に 高度の弾性線維, 膠原線維増生をきたし, しばしば骨硬化を伴う.
診断クライテリア
[WHO-5th and ICC diagnostic criteria for PMF]
PMF, Overt Fibrotic Stage (requires all 3 major criteria and at least 1 minor criterion)
Major Criteria
Megakaryocytic proliferation and atypia, accompanied by reticulin and/or collagen fibrosis grades 2 or 3
WHOcriteriaforBCR-ABL1-positive CML, PV, ET, MDS, or other myeloid neoplasms are not met
JAK2,CALR,orMPLmutation;orpresence of another clonal marker (e.g., ASXL1, EZH2, TET2, IDH1, IDH2, SRSF2, and SF3B1 mutations); or absence of reactive fibrosis
Minor Criteria (At least one, confirmed in 2 consecutive determinations)
Anemianotattributed to a comorbid condition
Leukocytosis ≧ 11000/μL
Palpable splenomegaly
Lactatedehydrogenase level above the upper limit of the institutional reference range
Leukoerythroblastosis
AP(10-19% blasts) and BP (≧20% blasts)
PMF, Prefibrotic/Early Stage (Requires All 3 Major Criteria and at Least 1 Minor Criterion)
Major Criteria
Megakaryocytic proliferation and atypia, without reticulin fibrosis grade > 1, accompanied by increased age-adjusted bone marrow cellularity, granulocytic proliferation, and (often) decreased erythropoiesis
WHO criteria for BCR-ABL1-positive CML, PV, ET, MDS, or other myeloid neoplasms are not met
JAK2,CALR,or MPL mutation; or presence of another clonal marker (e.g., ASXL1, EZH2, TET2, IDH1, IDH2, SRSF2, and SF3B1 mutations); or absence of minor reactive bone marrow reticulin fibrosis
Minor Criteria (At least one, confirmed in 2 consecutive determinations)
合併症に起因しない貧血 (Anemia not attributed to a comorbid condition )
白血球増多 Leukocytosis ≧ 11 ×109/μL
脾臓触知 Palpable splenomegaly
診断施設の正常上限値を超えるLDHの上昇 Lactate dehydrogenase level above the upper limit of the institutional reference range
[prefibrotic/ early stage PMFのクライテリア (WHO 4th revised)]
*1 Shao R, Ryder C, Wang L, et al. A Review of the Pathological and Molecular Diagnosis of Primary Myelofibrosis. Cancers (Basel). 2025 Dec 24;18(1):50. PMID: 41514563 *2 Shao R, Ryder C, Wang L, et al. A Review of the Pathological and Molecular Diagnosis of Primary Myelofibrosis. Cancers (Basel). 2025 Dec 24;18(1):50. PMID: 41514563 *3 Tefferi, A. Nicolosi, M.et al. A. Revised cytogenetic risk stratification in primary myelofibrosis: Analysis based on 1002 informative patients. Leukemia 2018, 32, 1189-1199. *4 Vaidya, R.et al., Mature survival data for 176 patients younger than 60 years with primary myelofibrosis diagnosed between 1976 and 2005； Evidence for survival gains in recent years. Mayo Clin. Proc. 2009, 84, 1114-1119.
![[PukiWiki]](image/title-logo.png "[PukiWiki]"){kind=logo}
primary MF-WHO5th.txt]]
