Abstract
A rare case of a posttraumatic extensive ganglion cyst of the anterolateral thigh with connection to the knee joint is presented. A 54- year-old man presented a palpable mass in the anterolateral region of his right thigh with a 15 months existing sense of fullness and tightness. He had an accident with his bicycle 21 months ago. Magnetic resonance imaging (MRI) was performed showing a cyst inside the quadriceps femoris muscle between vastus lateralis and intermedius with connection to recessus suprapatellaris and knee joint. In addition MRI detected a traumatic lesion in the quadriceps femoris tendon in the near of the knee joint. The ganglion cyst was 18 cm long and was excised completely. Intraope - ratively, the knee joint connection was confirmed and excised as well. The ganglion cyst was filled with a gelatinous and viscous fluid.