Diagnosis and treatment of joint-related tumors that mimic sports-related injuries.

Tumors involving the joint or having symptoms in the joint are rare. Both joint-related tumors and sports-related injuries can affect young, active patients, and their symptoms often overlap. Sports medicine specialists rarely encounter synovial conditions, so expertise in this area is difficult to establish. Orthopaedic oncologists often see only patients with an advanced condition. The clinical presentation of a soft-tissue sarcoma may be similar to that of a common lesion such as a synovial cyst. Some benign or malignant bone tumors cause referred pain to distant joints, possibly leading to a delay in diagnosis or inappropriate initial surgery. For example, a hip or proximal femoral bone tumor commonly causes isolated knee pain. Conversely, because the symptoms of some sports-related conditions or pseudotumors (such as a rectus femoris tear, fascial herniation, myositis ossificans, an avulsion injury, an avulsive cortical irregularity, femoral diaphyseal periostitis, or pseudotumor deltoideus) are similar to symptoms of a sarcoma, overtreatment is possible. A sports medicine physician should be familiar with these conditions to facilitate accurate and expedient diagnosis with appropriate treatment.