ABSTRACT
The present study included 15 patients with ulcerative colitis in various degrees of severity [mild, moderate and severe] and 5 healthy individuals as a control group to assess the ultrascructural changes of the mucosa in ulcerative colitis patients. Full length colonoscopic examination was done to all patients. Mucosal biopsies were taken from the inflamed mucosa and processed for histological and electron microscopic examination. These biopsies were compared with similarly processed ones from controls. The study showed the presence of ultrastructural mucosal changes in ulcerative colitis patents in the form of mitochondrial swelling, lack of microvilli, multiple secondary lysosomes, swollen goblet cells, peripheral condensation of nuclear chromatin, loss of tight junction and infiltration of the inflamed mucosa and epithelium with eosinophils. These changes were more frequent as the disease increases in severity. Dysplasia - like changes such as indentation of the nucleus, peripheral condensation of chromatin and flattening of cells were demonstrated in only two patients with severe and long-term U.C. The control biopsies appeared to be ultrastructurally normal. In conclusion, ulcerative colitis is associated with many ultrastructural mucosal Changes which are more frequent as the disease increases [progresses] in severity. These changes may be involved in the pathogenesis of ulcerative colitis and its related neoplasia