Essential thrombocytosis
Background
- Rare, chronic myeloproliferative neoplasm
- Abnormal proliferation is seen in megakaryocytic line only
- Typically in elderly
- Generally asymptomatic
Clinical Features
- Leukocytosis
- Anemia
- Splenomegaly
- Clotting or bleeding
Differential Diagnosis
Reactive thrombocytosis
- Acute blood loss
- Acute hemolytic anemia
- Iron deficiency anemia
- Treatment of vitamin B12 deficiency
- Rebound effect after thrombocytopenia treatment
- Metastatic cancer
- Lymphoma
- Rheumatologic disorders
- IBD
- Celiac disease
- Kawasaki disease
- Nephrotic syndrome
- POEMS syndrome
- Thermal burn
- MI
- Severe trauma
- Acute pancreatitis
- Post-surgery, especially splenectomy
- CABG
- TB
- Acute bacterial/viral infections
- Asplenia
- Allergic reaction
- Medication reactions: vincristine, epinephrine, glucocorticoids, IL-1B, ATRA, thrombopoietin, LMWH[1]
Autonomous thrombocytosis
Spurious (false) thrombocytosis
- Mixed cryoglobulinemia
- Cytoplasmic fragments
- Bacteremia
Evaluation
Workup
- CBC
- Chem 7
- ESR
- Bone marrow biopsy sometimes needed
Evaluation[2]
Per the WHO guidelines, diagnosis of ET requires all of the following:
| Major criteria |
|---|
| Thrombocytosis ≥ 450 x 109L |
| Megakaryocyte proliferation with little to no granulocyte or erythroid proliferation |
| Not meeting criteria for CML, PV, PMF, MDS or other myeloid neoplasm |
| No evidence of reactive thrombocytosis or presence of JAK2V617F or other clonal marker |
Management
- ASA 81mg
- Myelosuppressive agents (hydroxyurea, Interferon-α)
- Anagrelide