A rare myeloproliferative neoplasm characterized by stem-cell derived clonal over proliferation of mature myeloid lineages, such as erythrocytes, leukocytes, and megakaryocytes, with variable degrees of megakaryocyte atypia, associated with reticulin and/or collagen bone marrow fibrosis, osteosclerosis, ineffective erythropoiesis, angiogenesis, extramedullary hematopoiesis, and abnormal cytokine expression.
A severely increased count of eosinophils in the blood defined as a blood eosinophil count of 1.5 × 10e9/L or greater (one and a half billion cells per liter).
Hypereosinophilia, JAK2V617F, and Budd-Chiari syndrome: who is responsible for what?
Mishchenko E, Tadmor T, Schiff E, Attias D, Polliack A. Am J Hematol. 2011;86(2):223-4.
While the association of BCS with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis is well documented, hypereosinophilia has only been described in sporadic cases [282117].
