Ulcer as a morphological term for different diseases appears inconsistently on the histological picture.The defect substance in the center of the ulcer appears in different shapes: its ground may be covered with a necrotic , fibrous plaque or can contain granulation tissue.
The margin of the ulcer stands out with necrosis, inflammation processes or even regeneration signs.Induration and undermining characterize specific forms of the ulcer.
Source: Albertinen-Atlas