Knee Popping and Clicking in a Pediatric Athlete: Meniscal Injury or Sports Tumor?

This case report presents a teenage patient who initially was thought to have a sports-related injury but ultimately was diagnosed with a primary soft tissue tumor. A previously healthy 16-year-old softball player presented with a history of left knee joint line pain, clicking, and swelling. The patient was presumed to have a lateral meniscus tear. However, magnetic resonance imaging demonstrated an intra-articular mass. Arthroscopy revealed a 2.5- ð 1.5-cm firm pedicular mass in the lateral joint. Histological exam demonstrated localized pigmented villonodular synovitis. The patient healed uneventfully and returned to sporting activities. This report re-emphasizes the possibility that ‘‘sports tumors’’ can mimic symptoms of a meniscal tear in young athletes. (Journal of Surgical Orthopaedic Advances 21(4):275–278, 2012)