The localized form of tenosynovial giant cell tumor or pigmented villonodular synovitis is rarely intraarticular in the knee. We reported a 40-year-old woman with a tenosynovial giant cell tumor arising from posterior cruciate ligament (PCL). She suffered sudden knee pain and locking without any reason for two days. A mass with a size of 1.7 × 0.8 × 0.7 cm in the fossa intercondyloidea was dete...