Histological changes in the cecum of rats infected with E. histolytica. A Transverse section of infected rat with E. histolytica 14 days post-infection. Showed cytolysis of the apical portion of crypts (C), degradation of the epithelium lining of the crypts (D), and infiltration of inflammatory cells (F). H&E stain, ×379. B Transverse section of infected rat with E. histolytica 28 days post-infection. Showed aggregation of inflammatory cells (A) as granuloma, inflammatory cells near the muscularis mucosa (F), dilated intestinal crypts (C), edematous submucosa (SM), necrotic material (N), and thick muscularis externa wall (ME). H&E stain, × 379.