Table 134.3Diagnostic Criteria for Essential Thrombocythemia

Platelet count ≥ 600,000/μL*
No cause for reactive thrombocytosis
Hematocrit < 40% or red cell mass < 125% of mean normal predicted value
Normal red cell mean corpuscular volume or serum ferritin or marrow iron stain
Grade 3, 4 reticulin fibrosis of marrow absent
Collagen fibrosis of marrow absent or < one-third of biopsy area without both splenomegaly and leukoerythroblastic reaction in peripheral blood
No cytogenetic or morphologic evidence of myelodysplasia
No Philadelphia chromosome

≥400,000/μL and typical histology of bone marrow biopsy.

Modified from Murphy and colleagues.85

From: Chapter 134, Polycythemia Vera and Essential Thrombocythemia

Cover of Holland-Frei Cancer Medicine
Holland-Frei Cancer Medicine. 5th edition.
Bast RC Jr, Kufe DW, Pollock RE, et al., editors.
Hamilton (ON): BC Decker; 2000.
© 2000, BC Decker Inc.

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