Arthroscopic Removal of Tenosynovial Giant-Cell Tumors of the Cruciate Ligaments. Presentation of Two Cases

BACKGROUND: Tenosynovial giant-cell tumor (GCT) arising from cruciate ligaments consists a rather rare entity. Predominantly areas where this tumor appears are the palmar sides of fingers and toes. The involvement of larger joints such as the knee or the ankle is rather rare, but, in the case of synovial joints, the knee joint is particularly affected. Furthermore, rare seems to be the intra-articular localization of the tenosynovial GCT of the tendon sheath. Hereby, we present an arthroscopic approach of treatment with two cases. CASE REPORTS: The first case was a 32-year-old male with a GCT arising from the anterior cruciate ligament (ACL). The second case was a 26-year-old male with a GCT arising from the posterior cruciate ligament (PCL). In the first case, a round-shaped mass with a reddish-brown color was located just anterior to the ACL and impeded the full extension of the knee joint, while, in the second case, a well-circumscribed oval-shaped mass was found with a peduncle attached to the synovium of the PCL. After arthroscopic excision, both patients became asymptomatic, with complete lack of pain and full ROM. CONCLUSIONS: There is a lack of clinical features for the GCT of the knee, and thus, a thorough clinical examination is prudent. Usually, the diagnosis is set after an investigation based on suspicion. This entity can present with symptoms of instability and patients may present signs of mechanical derangement. With the knee joint, meniscal symptoms and locking are often present. The best non-invasive technique to diagnose this tumor has been reported to be the magnetic resonance imaging. Arthroscopic excision has been reported as a safe and effective procedure for treatment.