The cystic adventitial disease of the popliteal artery: from imaging to histopathology

Cystic adventitial disease (CAD) is a rare non-atherosclerotic vascular disease, presenting with claudication symptoms usually in young males without any risk factors. Even though many cases have been described, the precise cause of this disease remains unknown. The incidence of CAD is 1:1200 calf claudication cases 1 . The disease causes myxomatous cystic tumor growth in the adventitial layer of a blood vessel, effectively causing external compression of the lumen and slowing down the blood flow. It mostly involves arteries, typically in (but not limited to) the popliteal region. However, it can also affect veins. Even though this disease can only be observed in asymptomatic patients, the only definitive treatment relies on surgical removal or marsupialization of the cyst. The following vignette case describes the clinical factors, treatment, and response of an adult who presented with a CAD of the popliteal artery. A 41-year-old white male, treated only for Klinefelter syndrome with testosterone substitution, presented with 14 days of claudication pain in the right calf. He reported pain, which occurred after a walking distance of 50–100 m and was accompanied by cold and pins-and-needles sensations in the affected area, without any limitation to movement or sensitivity. However, no similar problems had been experienced before-hand, and on examination, a colder right leg below the knee was revealed, with no palpable pulse in the popliteal area or more distally, with a positive Homans sign. The rest