Newborn with a cystic right adnexal mass on prenatal US Pediatric Imaging Gastrointestinal July 22, 2025April 2, 2025 Transverse (above) and sagittal (below) US of the abdomen shows a cystic lesion with septations that has a hyperechoic inner rim (echogenic rim sign). The diagnosis was ileal duplication. Related Published July 22, 2025April 2, 2025