CT APPEARANCES OF INVOLVEMENT OF THE PERITONEUM, MESENTERY AND OMENTUM IN WILMS-TUMOR

Background. Peritoneal involvement by Wilms' tumor indicates stage III disease. CT is the single preferred modality in determining the exten t and staging of Wilms' tumor; however, the CT appearances of Wilms' t umor involvement of the peritoneum have not been specifically addresse d in the literature. Objective. The objective of this study was to dem onstrate the CT manifestations when there is involvement of the perito neum, mesentery and/or omentum in Wilms' tumor. Materials and methods. Four cases of Wilms' tumor form the basis of this report. They were e xamined on Elscint CT scanners. Results. Masses (''dropped metastases' ') in the pelvis were present in all four patients. Three patients had masses in the mesentery of the small bowel and sigmoid colon. Infiltr ation of the greater omentum was identified in two patients as a mantl e of tumor separating bowel from the anterior abdominal wall. Ascites was present in two patients. In one patient broad-based solid masses o f varying sizes were noted on the parietal and on the visceral surface s of the peritoneum, and in a different patient a discrete mass was no ted in the lesser omentum. Conclusion. The peritoneal spaces, recesses , ligaments and folds are invisible unless invaded by disease which is well demonstrated on CT.