Giant cell tumor of tendon sheath.

The authors present two case studies of giant cell tumor of tendon sheath. This uncommon lesion of the lower extremity is presented in these two cases in correlation with clinical, radiographic, and intraoperative findings. After the pathologic diagnosis was made, the patient in the first case decided not to have the tumor resected.

Magnetic resonance imaging of calcaneal aneurysmal bone cyst.

A 7-year-old black male presented with a lytic, expansile lesion of the calcaneus. This lesion was studied with conventional x-rays as well as MRI. The MR examination demonstrated a multiloculated lesion with material of a high- and low-signal intensity appreciated within each loculation.

Osteoid osteoma. Distant, periarticular, and subarticular lesions as a cause of knee pain.

Osteoid osteoma, a benign osteoblastic tumour comprised of osteoid and atypical bone, is a well-known entity. However, clinical diagnosis may be delayed, especially when the pain is referred to a nearby joint. This paper reports a series of 11 cases occurring in physically active patients in whom the diagnosis was delayed because of pain referral to the knee.