[Imitation of acute, deep venous thrombosis of the lower leg by a ruptured Baker's cyst].

In case of a swollen leg, differential diagnosis includes deep venous thrombosis. After having ruled out a thrombosis by venography, other causes have to be sought. We report a case where massive swelling of the lower leg was due to the arthrographically proven rupture of a Bakers' Cyst. Had more emphasis been put on recording the patients history, time loss and diagnostic procedures could have been minimized.