A 21-year-old male footballer has presented, for a few months after trauma a local discomfort in particular in the left popliteal fossa during palpation and usual daily activities. 
Physical examination was negative for the presence of a soft mass in the upper part of the popliteal left fossa without local signs of inflammation. Instead was positive for the pain in the front part of the left knee during palpation. There was no evidence of clinical signs of peripheral arterial angiopathy. Chest and abdomen examination, arterial blood pressure, chest X-ray, oxygen saturation, and electrocardiogram were normal. 
Duplex scanning, Computed Tomography scanning, and Magnetic Resonance imaging (MRI) are considered to be important non-invasive diagnostic methods for the diagnosis of PVA. 
Magnetic Resonance imaging (MRI) without contrast media demonstrated a 4 x 2 cm oval formation with dishomogeneous hyperintensity on T1-and T2-weighted sequence in the left popliteal fossa adjacent to the vessels suspected for a blood lesion (Figure 1). 
Then the color-Doppler ultrasonography (US-CD) was performed to identify the true origins of this lesion. This examination demonstrated only a mixed echogenicity mass in the left popliteal fossa with no evidence of arterial or venous nature. 
Subsequently this mass was evaluated with Angio-Computed Tomography (ACT) using a computed tomography scanner (Highspeed Advantage, GE Medical System Milwaukee, WI, USA). 
Images were acquired without and with contrast media intravenously (a single bolus of 120 cc with a flow rate of 3.5 ml/s of nonionic contrast medium via an antecubital venous access) and a scan was obtained with three phases from the injection of contrast media. 
Every data acquired were transferred to an Advantage Windows workstation (GE Advantage) and reconstrued using maximal intensity projection (MIP) and volume rendering (VR) technique. 
The ACT acquisition confirmed a 36 mm x 17 mm oval mass in the left popliteal fossa continuous with the popliteal veins. This lesion had presented contrast enhancement only in delayed acquisition (180 sec) and so appeared to be a true venous aneurysm(Figures 2 and 3).
The PVA was repaired surgically via a posterior approach to the popliteal fossa. A 4 x 2 cm aneurysm was identified. In the same time open tangential aneurysmectomy and lateral vein reconstruction were realised (Figure 4). 
A histopathologic examination revealed an aneurysm venous wall with none evidence of inflammatory or degenerative signs. 
The patient was given warfarin for anticoagulation and was discharged on the 3th postoperative day. Two months postoperatively, the patient's symptoms were improved; the repetition of venous duplex scanning showed patency of the repaired popliteal vein without venous thrombosis. 
Elastic stockings were suggested for support, and daily aspirin was recommended for prophylaxis against thrombosis. The patient was able to resume normal activities.