Update on Management of Incidental Findings Seen on Imaging Studies of the Abdomen and Pelvis.

Incidental findings (IFs) are findings on imaging studies obtained for indications unrelated to the IF. IFs may represent clinically important lesions such as malignancy. However, the vast majority are benign with no clinical relevance. IFs can lead to unnecessary follow-up imaging, procedures, and iatrogenic complications, resulting in significant financial and psychologic burden to patients and the health care system. To address this, the American College of Radiology released a series of white papers that provide management guidelines for a variety of IFs in different organs. Since the original white papers and subsequent updates were published, a wealth of research has been provided on various IFs that is either concordant with or contradictory to previous guidelines. Additionally, there are multiple common IFs that are not discussed in an existing white paper. The authors discuss updated evidence regarding common IFs for various topics including hepatic findings (hyperenhancing liver lesions at CT, echogenic liver lesions), biliary findings (asymptomatic biliary ductal dilatation, focal fundal gallbladder wall thickening, gallbladder polyps), renal findings (indeterminate homogeneous renal mass at CT, hyperechoic renal lesions, hyperintense renal lesions at T1-weighted MRI), adrenal nodules, splenic lesions, bowel and mesenteric findings (intussusception, misty mesentery), and male reproductive findings (testicular microlithiasis, isolated right-sided varicocele). The authors review recent literature that addresses existing white paper topics and common IFs that are not discussed in existing white papers. ©RSNA, 2026.