Background: Osteoid osteoma is one of the unusual causes of musculoskeletal pain. Its diagnosis is usually not difficult in classic diaphyseal localization. However, the diagnosis of juxta or intraarticular osteoid osteoma is challenging because of atypical clinical presentation responsible for long diagnosis delay.
Aim: Report a new case.
Case report: We report herein the case of a 22-year-old woman presenting an intraarticular osteoid osteoma of the elbow. Diagnosis has been established on imaging findings (MRI and CT-scan) after 10 months because of atypical clinical presentation as a chronic monoarthritis of the elbow. The picture of an osteoid osteoma of the lower extremity of the humerus associated to a synovitis and a joint effusion was suspected on MRI. It had been confirmed on CT-scan wich showed the nidus. Surgical removal of the tumor allowed pain relief and functional restoration in postoperatively.
Conclusion: Regarding an unexplained chronic monoarthritis, the diagnosis of intraarticular osteoid osteoma should be evoked. CT-can remains the investigation of choice for identifying the nidus. Surgical exicision permits the relief of symptoms.