Pediatric arterial aneurysm is rare disease. Among them, idiopathic-congenital arterial aneurysm is extremely rare. This is a case report of right common iliac artery idiopathic aneurysm with absence of right external iliac artery. A 4-year-old girl who had been complaining of intermittent abdominal pain since 2 years prior presented with a right lower abdominal mass that had been palpable since 6 months prior. Abdominal CT revealed a 5.2 cm × 4.5 cm × 5.1 cm, right-sided, partially thrombosed, saccular, iliac artery aneurysm. She underwent to operation, aneurismal resection. A pathological examination confirmed that it was a true aneurysm, considering that all layers of the vascular wall were stretched with no deficit. The patient was discharged 3 days after the surgery without any complication. Five months passed since the surgery, and the patient is doing well without any abdominal or leg pain.
Keywords: Aneurysm; Child; Iliac aneurysm; Vascular surgical procedure.