Histopathology of UC Active phase of inflammation Acute inflammation cells accumulate and invade the crypts Progressive changes Degeneration or necrosis of the crypt epithelium Crypt abscesses Shallow ulcerations extending to the lamina proprius Rarely and severe changes ToXic megacolon and spontaneous perforationHistopathology of UC Active phase of inflammation: Acute inflammation cells accumulate and invade the crypts Progressive changes: Degeneration or necrosis of the crypt epithelium Crypt abscesses Shallow ulcerations extending to the lamina proprius Rarely and severe changes: Toxic megacolon and spontaneous perforation