Subepithelial granuloma

Transmission electron micrograph showing the area of an ulcer at the periphery of the cornea. The epithelium with its basal lamina are to the lower right of the field and the subepithelial stroma with an accumulation of mast cells, active fibroblasts and pyknotic cells in amongst collagen matrix are to the upper left. The mast cells contain large dark granules and fibroblasts lie between the mast cells. The pyknotic cells have have dark, dense nuclei in th centre of the field. This field is approximately 27nm across.