cytology
Last reviewed 01/2018
Microscopically, mast cells are ovoid in shape and have a small, spherical nucleus that is virtually swamped by surrounding cytoplasmic granules. The granules stain stongly with basic dyes.
Ultrastructural study reveals little by means of synthetic machinery in the cytoplasm e.g. a paucity of mitochondria. The granules are semi-crystalline and membrane-limited. They contain an array of active substances which are released on degranulation.