Intestinal accumulation of 111In-granulocytes in patients studied because of occult infection.

111In-granulocyte scintigraphy was performed on 245 patients in whom a localized infection was suspected. In 123 patients scintigraphy was positive and of these 35 (28%) had intestinal accumulations of 111In-granulocytes. Specific local causes for the intestinal uptake of radioactivity were antibiotic associated colitis (eight patients), local pyogenic bowel infection (four patients), systemic disease (two patients), bowel necrosis (two patients), colonic cancer (one patient) and Stevens-Johnson's syndrome (one patient). Nonspecific mechanisms of bowel accumulation were desquamation of labelled granulocytes (12 patients) and bleeding (two patients). In three cases the mechanism of colonic accumulation of granulocytes was not revealed. These results show that unexpected accumulations of labelled granulocytes in the gut is not a rare phenomenon and is often due to clinically significant intestinal inflammation or other disease, especially in patients who do not have signs of respiratory, pancreatic or oesophageal inflammation causing desquamated granulocytes to accumulate in the gut.