Abstract

Intermittent claudication in a healthy, middle-aged man who does not present with any of the traditional risk factors for arterial disease is rare and often misdiagnosed. In fact, a diagnosis of peripheral obstructive arterial disease in a nonsmoker, nondiabetic, nonhypertensive, and nonhyperlipidemic young male is difficult for a general physician to even contemplate, especially when the patient has palpable dorsalis pedis and posterior tibial arteries. Young, healthy patients who present with claudication resulting from popliteal artery stenosis due to external pressure, with intact arterial pulses, may have cystic adventitial disease (CAD). CAD is a cystic adventitial degeneration localized primarily in the popliteal artery. Although the pathogenesis of the disease remains controversial, what is certain is that the cystic degeneration is not primarily a dysplasia of the vessel wall itself, but originates from ectopic tissue of the joint capsule or bursa of the knee. Microscopic analysis of the cyst reveals collagenous and muscular fibers with focal necrosis, while the lumen is filled with mucinous, thick gelatinous fluid containing mainly amino acids.¹ The cysts may be multiple or multiloculated. The pathology has been described as “subadventitial pseudocyst,” “mucinous cystic dissecting intramural degeneration,” “cystic mucoid degeneration,” and “cystic myxomatous adventitial degeneration.”