Spontaneous resolution of cystic adventitial disease: a word of caution.

Spontaneous resolution of cystic adventitial disease has been occasionally reported in the literature. It is unclear, however, whether this resolution is permanent. In this case report, we describe recurrence of a popliteal artery cystic adventitial disease after spontaneous resolution, which was successfully treated with surgery. The underlying mechanism is proposed. Without definitive treatment, the patients with spontaneous resolution of cystic adventitial disease may need long-term follow-up, given the risk of recurrence.