Synopsis
Recognise marrow fibrosis and extramedullary haematopoiesis, distinguish prefibrotic and secondary disease, quantify molecular risk and integrate symptom control with early curative transplant assessment.
- Suspect myelofibrosis with massive splenomegaly, constitutional symptoms, anaemia, teardrop cells, nucleated red cells, left-shifted granulocytes, raised LDH or a dry marrow aspirate.
- First-line assessment is FBC and expert film, reticulocytes, haemolysis, iron, B12 and folate, renal, liver, urate and LDH plus examination of spleen, liver, symptoms and thrombosis.
- Confirm with bone-marrow trephine for atypical megakaryocytes and fibrosis, cytogenetics and JAK2, CALR and MPL testing; exclude BCR-ABL1 and secondary fibrosis.
Key red flags
Sudden left upper-quadrant pain, shoulder-tip pain, guarding, hypotension or haemoglobin fall with massive splenomegaly suggests infarction, haemorrhage or rupture and needs urgent imaging and surgical input.
Rising circulating blasts, rapid count decline, severe systemic symptoms or new tissue masses needs same-day specialist escalation.
Investigation priorities
Recognise the phenotype and identify treatable contributors to cytopenia.
Management branches
Leucoerythroblastosis, teardrops, splenomegaly or unexplained cytopenia suggests fibrotic marrow disease.
- Assess reversible cytopenia causes, symptoms, spleen, thrombosis and prior PV or ET phenotype.
- Obtain trephine with expert morphology, fibrosis grade, blasts, cytogenetics, JAK2, CALR, MPL and broader myeloid testing.
Key medicines
RuxolitinibStart orally twice daily by platelet count: 20 mg above 200 × 10⁹/L, 15 mg at 100 to 200 × 10⁹/L, 10 mg at 75 to below 100 × 10⁹/L and 5 mg at 50 to below 75 × 10⁹/L; do not start below 50 × 10⁹/L.
MomelotinibGive 200 mg orally once daily while benefit persists; start 150 mg once daily in severe Child-Pugh C hepatic impairment, reduce toxicity doses in 50 mg steps and discontinue if 100 mg once daily is not tolerated.