A case of pseudothrombophlebitis due to inguinal synovial cyst.

: A case of pseudothrombophlebitis of the whole right leg by an inguinal synovial cyst that had a compressed femoral vein is presented. Differential diagnosis is important in order to avoid hemorrhagic complications. The usefulness of ultrasonography and necessity of phlebography are emphasized. Radical excision of the cyst is recommended.