missed forearm artery pseudoaneurysm following a direct stab wound

Introduction: pseudoaneurysm, accompanied by penetrating trauma in the forearm, is rarely reported. considering that clinical examination is not standard in these cases, clinical suspicion and application of suitable diagnostic modalities would be promising and helpful. most of these patients were referred to the emergency units but were not correctly diagnosed. case presentation: in this report, we present a 22-year-old patient with increasing pain because of a stab wound to forearm 10 days after the first referral to the emergency unit. a pseudoaneurysm was suspected in posterior interosseous of the radial artery because of the persistent pain and palpation of mass. conclusions: the results of bedside ultrasound in the emergency unit and ct angiography revealed pseudoaneurysm in posterior interosseous of the radial artery. the surgical treatment was the resection of the lesion and posterior interosseous ligature. all symptoms of the patient were resolved in a 2-months follow-up. post-traumatic upper extremity pseudoaneurysm can show its signs and symptoms after a long time.