Tenosynovial giant-cell tumor arising from the anterior cruciate ligament of the knee.

The localized form of tenosynovial giant-cell tumor is rarely located intraarticularly, especially in the large weight-bearing joints. We report the first case of localized, intraarticular tenosynovial giant-cell tumor arising from the anterior cruciate ligament of a knee in which locking and effusion had occurred. After arthroscopic removal of this tumor, the patient became asymptomatic.