A 19-year-old male with persistent unilateral knee pain, possibly due to a mid-diaphyseal osteoid osteoma of the femur?
Osteoid osteoma is a benign bone-forming tumor that typically presents itself during the second decade and more frequently in males. The main complaint is progressive pain, usually pain at night. The pain is relieved by nonsteroidal anti-inflammatory medication. However, osteoid osteoma can present itself in a rather nonspecific pattern, for example with referred pain.
On radiographs an osteoid osteoma has a characteristic image of a small round lucency (nidus) with sclerotic margin, which is best visualized with CT scan. Treatment can either be conservative with an oral NSAI or surgical, where nowadays CT guided radiofrequency ablation seems to be the primary choice.