Diagnostic criteria for PMF and SMF, by the 2022 ICC
| Diagnosis . | PMF, early/prefibrotic stage (pre-PMF) . | PMF, overt fibrotic stage (overt PMF) . | PPV-MF . | PET-MF . |
|---|---|---|---|---|
| Major/required criteria | Megakaryocytic proliferation and atypia, BMF grade <2 Increased age-adjusted BM cellularity, granulocytic proliferation, and (often) decreased erythropoiesis | Megakaryocytic proliferation and atypia, accompanied by reticulin and/or collagen BMF grade 2 or 3 | BMF grade 2 or 3 | |
| JAK2, CALR, or MPL mutation, or the presence of another clonal marker, or absence of reactive BM reticulin fibrosis | Previous established diagnosis of PV/ET | |||
| Diagnostic criteria for ET, PV, BCR::ABL1-positive CML, myelodysplastic syndromes, or other myeloid neoplasms not met | ||||
| Minor/additional criteria | Anemia not attributed to a comorbid condition | Anemia∗ | ||
| Leukoerythroblastosis | Leukoerythroblastosis | |||
| Palpable splenomegaly | Palpable splenomegaly: newly or increased of >5 cm from BL | |||
| Leukocytosis ≥11 × 109/L | Development of ≥2 constitutional symptoms: >10% weight loss in 6 mo, night sweats, unexplained fever (>37.5°C) | |||
| LDH level above the range | LDH level above the range | |||
| The diagnosis of pre-PMF or overt PMF requires all 3 major criteria and at least 1 minor criterion confirmed in 2 consecutive determinations | The diagnosis of PPV-MF or PET-MF is established by both required criteria and at least 2 additional criteria | |||
| Diagnosis . | PMF, early/prefibrotic stage (pre-PMF) . | PMF, overt fibrotic stage (overt PMF) . | PPV-MF . | PET-MF . |
|---|---|---|---|---|
| Major/required criteria | Megakaryocytic proliferation and atypia, BMF grade <2 Increased age-adjusted BM cellularity, granulocytic proliferation, and (often) decreased erythropoiesis | Megakaryocytic proliferation and atypia, accompanied by reticulin and/or collagen BMF grade 2 or 3 | BMF grade 2 or 3 | |
| JAK2, CALR, or MPL mutation, or the presence of another clonal marker, or absence of reactive BM reticulin fibrosis | Previous established diagnosis of PV/ET | |||
| Diagnostic criteria for ET, PV, BCR::ABL1-positive CML, myelodysplastic syndromes, or other myeloid neoplasms not met | ||||
| Minor/additional criteria | Anemia not attributed to a comorbid condition | Anemia∗ | ||
| Leukoerythroblastosis | Leukoerythroblastosis | |||
| Palpable splenomegaly | Palpable splenomegaly: newly or increased of >5 cm from BL | |||
| Leukocytosis ≥11 × 109/L | Development of ≥2 constitutional symptoms: >10% weight loss in 6 mo, night sweats, unexplained fever (>37.5°C) | |||
| LDH level above the range | LDH level above the range | |||
| The diagnosis of pre-PMF or overt PMF requires all 3 major criteria and at least 1 minor criterion confirmed in 2 consecutive determinations | The diagnosis of PPV-MF or PET-MF is established by both required criteria and at least 2 additional criteria | |||
BL, baseline; BM, bone marrow; BMF, bone marrow fibrosis; CML, chronic myeloid leukemia; ET, essential thrombocythemia; LDH, serum lactate dehydrogenase; PV, polycythemia vera.
For PPV-MF, also a sustained loss of requirement of phlebotomies or cytoreduction; for PET-MF a >2 g/dL decrease from BL hemoglobin value