Our diagnostic workup of patients with thrombocytosis
| Fields/investigations . | Questions and/or assessments . |
|---|---|
| Familial history | Relatives with thrombocytosis or other known hematologic disorders |
| Medical history | Diseases or conditions that can be associated with thrombocytosis (eg, malignancy, inflammatory bowel disease, iron deficiency, splenectomy, bleeding) |
| Vascular complications (thrombosis or bleeding) | |
| Comorbidities like diabetes, hypertension, or dyslipidemia | |
| Lifestyle | Smoking, physical activity, dietary habits |
| Medications | Regular and/or recent use of drugs |
| Symptoms | Headache, vertigo, dizziness, tinnitus, erythromelalgia, paresthesias, or systemic symptoms (weight loss, night sweats, fever) |
| Physical examination | Presence of splenomegaly and/or hepatomegaly |
| First-level tests* | CBC count and evaluation of peripheral blood smear |
| Evaluation of body iron status (serum iron, TIBC, transferrin saturation, and serum ferritin)† | |
| CRP | |
| Screening for BCR-ABL1 rearrangement | |
| Tests for JAK2 (V617F), CALR exon 9 indels, and MPL exon 10 mutations, to be performed sequentially on granulocyte DNA‡ | |
| Second-level tests | Bone marrow evaluation through bone marrow aspirate and biopsy (H&E or Giemsa, Gomori and Perls staining) |
| Further laboratory tests (eg, von Willebrand factor when PLT count is ≥1000 × 109/L or when an acquired von Willebrand syndrome is anyhow suspected) and radiological/ultrasound examinations |
| Fields/investigations . | Questions and/or assessments . |
|---|---|
| Familial history | Relatives with thrombocytosis or other known hematologic disorders |
| Medical history | Diseases or conditions that can be associated with thrombocytosis (eg, malignancy, inflammatory bowel disease, iron deficiency, splenectomy, bleeding) |
| Vascular complications (thrombosis or bleeding) | |
| Comorbidities like diabetes, hypertension, or dyslipidemia | |
| Lifestyle | Smoking, physical activity, dietary habits |
| Medications | Regular and/or recent use of drugs |
| Symptoms | Headache, vertigo, dizziness, tinnitus, erythromelalgia, paresthesias, or systemic symptoms (weight loss, night sweats, fever) |
| Physical examination | Presence of splenomegaly and/or hepatomegaly |
| First-level tests* | CBC count and evaluation of peripheral blood smear |
| Evaluation of body iron status (serum iron, TIBC, transferrin saturation, and serum ferritin)† | |
| CRP | |
| Screening for BCR-ABL1 rearrangement | |
| Tests for JAK2 (V617F), CALR exon 9 indels, and MPL exon 10 mutations, to be performed sequentially on granulocyte DNA‡ | |
| Second-level tests | Bone marrow evaluation through bone marrow aspirate and biopsy (H&E or Giemsa, Gomori and Perls staining) |
| Further laboratory tests (eg, von Willebrand factor when PLT count is ≥1000 × 109/L or when an acquired von Willebrand syndrome is anyhow suspected) and radiological/ultrasound examinations |
H&E, hematoxylin and eosin; TIBC, total iron-binding capacity.
First-level tests are performed at the same time, with the only exception being tests for JAK2 (V617F), CALR exon 9 indels, and MPL exon 10 mutations, which are performed sequentially: (1) JAK2 (V617F); (2) if negative, CALR exon 9; (3) if negative, MPL exon 10.
We use a battery of tests for the evaluation of body iron status because this allows for distinguishing between the hypoferremia of iron deficiency and that of inflammation.
Granulocytes belong to the myeloproliferative clone, whereas lymphocytes do not: therefore, the use of granulocyte DNA allows better detection sensitivity and is of fundamental importance for quantitative assessment of the mutant allele burden.