Tenosynovial Giant Cell Tumor and Pigmented Villonodular Synovitis.

Tenosynovial giant cell tumors (TGCTs) are a spectrum of benign growths that can occur in both intra-articular and extra-articular locations. The pattern of involvement also varies from nodular, typically small-volume disease to extensive and diffuse synovial infiltration. Surgical resection remains the treatment of choice for most patients and resection techniques include arthroscopic, open, or a combined approach. However, TGCT can be locally aggressive and exhibit high recurrence rates even after adequate surgical removal. Improved understanding of the complex genetic and environmental factors that lead to these proliferative disorders have modernized treatment options. Discovery of the unique role that tumor cell expression of the colony-stimulating-factor1 and propagation of the inflammatory cascade has led to the use of adjuvant medications to improve outcomes. In-depth knowledge of the etiology, clinical presentation, diagnosis, workup, historical treatments, and new treatment options for patients with TGCT are crucial for orthopaedic surgeons to understand and work effectively with a multidisciplinary treatment team.