Cystic adventitial degeneration of the popliteal artery: lectin-histochemical study.

A case of cystic adventitial degeneration (CAD) of the popliteal artery is presented. Histologically the cyst appeared localised in the adventitia, outside the elastic lamina. A lectin-histochemical study evaluated the following peroxidase conjugated lectins: Peanut agglutinin, Concanavalin A, Ulex Europaeus (UEA I) and Wheat Germ Agglutinin. The lack of UEA I reactivity excluded an arterial origin of the cyst. Moreover, the lectin binding pattern of CAD appeared to be similar to the reactivity pattern of normal synovia.