B-mode Ultrasound and Contrast-Enhanced Ultrasound Pattern of Focal Extramedullary Hematopoiesis of the Spleen in a Patient with Myeloproliferative Disease.

The term myeloproliferative disease (MPD) includes various chronic hematologic disorders, for example, chronic myeloid leukemia, essential thrombocytosis, polycythemia vera and osteomyelofibrosis (Burkhardt R et al. J Clin Pathol 1986; 39: 237 – 252). MPD involves splenomegaly, especially in the accelerated phase of disease, and often results in splenic infarction, which appears in ultrasound as hypoechoic lesions (Görg C et al. Radiology 1990; 174: 803). In contrast, hyperechoic/isoechoic splenic lesions are rare among patients with MPD, and the cause of these lesions is mostly unknown due to the lack of histological confirmation (Görg C et al. Ann Hematol 2004; 83: 14 – 17).