Inconsistent Use of Terminology and Different Treatment Outcomes of Venous Adventitial Cystic Disease: A Proposal for Reporting Standards.

Adventitial cystic disease (ACD) is a very rare condition characterized by the accumulation of a cyst filled with gelatinous substance in the adventitia of a vessel adjacent to the joint area. The cyst usually compresses the vessel lumen, causing claudication or leg swelling. The disease usually affects the popliteal artery. However, several cases of venous ACDs particularly in the common femoral or external iliac vein have been reported. The definition, diagnosis, and optimal treatment of ACD remain controversial because of its rarity and the inconsistent use of terminology. The heterogeneity of the reported cases is more prominent in venous ACD. Herein, the accurate terminology of cysts correlated to the joint (synovial cyst, ganglion cyst, and adventitial cyst) and the pathogenesis, anatomy, and optimal therapy of venous ACD are discussed in detail to establish reporting standards for future studies.