Dissecting Popliteal Cyst Simulating Thrombophlebitis

Abstract

Dissecting popliteal cyst, as well as deep vein thrombophlebitis, should be considered in the differential diagnosis of calf swelling, particularly in the presence of associated arthritis of the knee, effusion and popliteal cyst. It is emphasized that such cases of calf swelling are often diagnosed erroneously as deep vein thrombophlebitis. The case hostories of 5 patients with dissecting popliteal cyst, 4 simulating deep vein thrombophlebitis and 1 simulating sciatic neuralgia, are presented. A brief discussion of the clinical conditions, differential diagnosis, etiology and pathogenesis, treatment, and clinical course associated with dissecting popliteal cyst is presented. The importance of early consideration of dissecting popliteal cyst in cases of calf swelling of undetermined etiology and in cases of atypical arthritis of the knee is emphasized. Positive contrast arthrography is recommended to confirm the presence of dissection popliteal cyst. A popliteal cyst may dissect upward into the thigh, as well as downward into the calf. Acute rupture of a popliteal cyst may develop into a chronic rheumatoid calf cyst without inflammation.