What is your diagnosis?

Isolated internal iliac artery aneurysms (IAAs) are rarely encountered in clinical practice, with an estimated incidence of 0.4%. They are more commonly seen in men aged 65 to 70 years, with a male to female ratio of 6:1 or greater. Smoking, hypertension, atherosclerosis, and male sex are the well-known risk factors for the development of IAAs. The vast majority of cases are found incidentally during ultrasound, CT, or angiography. Aneurysmal vessel size is the most important rupture determinant. Therefore, large aneurysms should be treated surgically or with endovascular coil embolization to prevent devastating complications, such as rupture and subsequent life-threatening bleeding. Patients with aneurysm of less than 3 cm in size can be managed conservatively with regular monitoring (1). Although iliac vein sarcoma is very rare, it should be considered in the differential diagnosis of retroperitoneal masses, especially in patients who present with leg swelling. Clinical diagnosis is frequently delayed, unless the tumor becomes a huge mass or occludes veins (2). As seen in Video 1 and Video 2, the present mass opacified during the arterial injection and this made us suspect the existence of an aneurysm, which was confirmed with subsequent CT. No association was found between the mass and previous hysterectomy. Bladder diverticula are generally seen in men over the age of 60, and most commonly occur lateral and superior to the ureteral orifices. Patients with large diverticula can present with hematuria, urinary tract infections, urinary retention, or rarely, acute abdomen due to rupture. Diverticulum can be misdiagnosed as ovarian cyst due to similar sonographic characteristics. In this case, there was no connection between the mass and the bladder (3). May-Thurner syndrome, also known as iliac vein compression syndrome, occurs when there is an overlap of the right common iliac artery over the left common iliac vein against the vertebral body. Due to high-pressure arterial pulsations over the vein, it can lead to recurrent, left-sided deep venous thrombosis. In the suspicion of this rare syndrome, contrast-enhanced CT or iliac venography can confirm left common iliac vein compression (3). This case highlights the importance of detailed medical history and multimodality imaging in order to prevent unpleasant pitfalls as a result of misdiagnosis.