Primary sarcoma of the anterior cruciate ligament - a case report.

Clear cell sarcoma of tendons and aponeuroses (CCSTA) is a rare, aggressive soft tissue malignancy, which is found in intimate association with tendon, aponeurosis or fascia. It has not previously been reported in association with intraarticular ligaments. We report the first case of an intraarticular CCSTA, in this case of the anterior cruciate ligament and describe the diagnostic and treatment challenges of intraarticular tumours of the knee.