Tumors

Tumors in and around the knee joint are extremely rare.
Non malignant tumors and tumor like conditions include Pigmented Villo Nodular Synovitis (PVNS), Synovial Chondromatosis, Exostosis and Bone Cysts. These conditions present in a variety of ways and require considerable experience and expertise to sort out and treat. They are often discovered coincidentally or at arthroscopy for other conditions or they may mimic other conditions. These Benign (non malignant) tumors are usually able to be removed by partial synovectomy or local removal. They have an annoying habit of local recurrence but are not a form of cancer.
Malignant tumors are even harder to diagnose early and include Osteosarcoma, Chondrosarcoma, Ewings Tumor and secondary tumors. These cancer conditions require very expert medical attention and detailed investigation and treatment. They are not always life threatening.