Diagnosis and Treatment Options in Pigmented Villonodular Synovitis of the Knee: A Narrative Review.

Background: Pigmented villonodular synovitis (PVNS), also known as tenosynovial giant cell tumor, is a rare proliferative disorder of the synovial membrane that primarily affects the knee joint. Despite advances in imaging and surgical techniques, diagnosis is often delayed, and optimal treatment remains debated. Methods: A Narrative review was conducted according to PRISMA guidelines using PubMed, MEDLINE, and Scopus databases from January 2000 to December 2024. Studies reporting on epidemiology, clinical features, imaging, treatment, and outcomes of PVNS were included. Results: Sixty-six studies encompassing 120 patients were included. The majority of cases were diffuse PVNS. MRI was the most effective imaging tool. Arthroscopic synovectomy was the most common treatment, though recurrence rates remained high, particularly in diffuse forms. Adjuvant treatments, including radiosynoviorthesis and biologic therapies such as infliximab or pexidartinib, were employed in recurrent or unresectable cases. Conclusions: Early diagnosis and complete surgical excision remain the mainstay of treatment. Combined open and arthroscopic approaches are recommended in diffuse PVNS. Further prospective studies are needed to define optimal long-term management.