Prospective study of thrombophlebitis and "pseudothrombophlebitis".

43 non-surgical patients presenting with calf pain and a clinical diagnosis of deep venous thrombosis (DVT) were studied by arthrography, venography, and ultrasound. Only 14 had venographic evidence of DVT; 5 of these had popliteal cysts, which in 4 cases probably contributed to symptoms. 11 patients had popliteal cysts and normal venograms, and 9 of these cysts were thought likely to be the cause of the symptoms. In 18 patients all investigations were normal. Physical signs were not helpful in distinguishing between the three groups of patients. Ultrasonography detected only 2 of the 16 popliteal cysts. Popliteal cysts should be considered in the differential diagnosis and as a possible coexisting condition in patients suspected clinically of having DVT. Also, the finding of a Baker's cyst should not deter one from doing a venogram.