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Medical Term:


Pronunciation: mi'e-lo-sit


  1. A young cell of the granulocytic series, occurring normally in bone marrow, but not in circulating blood (except in certain diseases). When stained with the usual dyes, the cytoplasm is distinctly basophilic and relatively more abundant than in myeloblasts or promyelocytes, even though myelocyte's are smaller cells; numerous cytoplasmic granules (neutrophilic, eosinophilic, or basophilic) are present in the more mature forms of myelocyte's, and the first two types are peroxidase positive. The nuclear chromatin is coarser than that observed in myeloblasts, but it is relatively faintly stained and lacks a well-defined membrane; the nucleus is fairly regular in contour (not indented), and seems to be “buried” beneath the numerous cytoplasmic granules.
  2. A nerve cell of the gray matter of the brain or spinal cord.

Synonym(s): medullocell

[myelo- + G. kytos, cell]

© Copyright 2016 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.