A dissecting popliteal cyst presenting as acute thrombophlebitis.

A patient with psoriatic arthritis presented to the Geisinger Medical Center emergency department after the sudden onset of pain and swelling in his left calf. Initially, the patient was thought to have acute thrombophelebitis. Upon further examination, the diagnosis of a ruptured popliteal cyst was considered, and was confirmed with arthrography. The case illustrates an occurrence of a dissecting popliteal cyst simulating an cute deep vein thrombosis in a patient with an inflammatory process involving the knee.