Evaluation and Management of Intra-Articular Tumors of the Knee

Intra-articular tumors of the knee are most commonly benign. Overall, this is a relatively rare clinical presentation. The differential diagnosis includes pigmented villonodular synovitis, synovial chondromatosis, lipoma arborescens, synovial hemangioma, and very rarely primary sarcoma (synovial sarcoma being the most common). The clinical presentation for these conditions is usually non-specific, but radiographic and advanced imaging findings are able to differentiate some of these tumors. It is essential to obtain and send tissue specimens to pathology for histologic analysis to rule out a primary malignancy as a missed diagnosis can have grave implications on patient outcomes. This review summarized key aspects of diagnosis and treatment for these conditions.