megakaryoblast


megakaryoblast

 [meg″ah-kar´e-o-blast″] the earliest cytologically identifiable precursor in the thrombocytic series, which matures to form the promegakaryocyte.

meg·a·kar·y·o·blast

(meg'ă-kar'ē-ō-blast'), The precursor of a megakaryocyte. Synonym(s): megacaryoblast

megakaryoblast

The most immature cell of the megakaryocytic series, which is round or ovoid, and large but variably sized (7–35 µm in diameter; those measuring < 15 µm are termed micromegakaryoblasts). The nuclei are round or oval, contain 1+ nucleoli and have a coarse granular pattern; cytoplasm is scant, blue, agranular, often rims the nucleus, occasionally with several small, blunt, budding peripheral protrusions. Megakaryoblasts are normally found only in the marrow, but may be seen in blood smears with myeloproliferative disorders, especially postsplenectomy.

meg·a·kar·y·o·blast

(meg'ă-kar'ē-ō-blast) The precursor of a megakaryocyte.