[The pseudothrombophlebitic syndrome: a new diagnostic approach].

The clinical manifestation of popliteal or Baker's cysts, either intact or complicated due to rupture or dissection, can be a thrombophlebitis (pseudothrombophlebitis), greatly difficulting the differential diagnosis and the management of these patients, being their treatment completely different. The doppler echography is a reliable, quick and low-cost method which allow to differentiate between this two types of pathology and the magnetic resonance (MR) is the ideal technique to assess the complications of popliteal cysts. We present a case of pseudothrombophlebitis due to compression of the popliteal vein by a Baker's cyst.