Osteoid osteoma mimicking monoarticular juvenile idiopathic arthritis in a girl.

Osteoid osteoma (OO) is a benign osteogenic neoplasm, usually affecting children and young adults, that is typically characterized by nocturnal pain and response to non-steroidal anti-inflammatory drugs. OO is frequently misdiagnosed because it mimics juvenile idiopathic arthritis (JIA), bone infection or malignancy. Herein we report the case of a girl who presented with chronic monoarthritis of the knee mimicking JIA.

Unusual onset of a case of chronic recurrent multifocal osteomyelitis.

Background: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition that commonly affects the clavicle and pelvis.

Case Presentation: We report here a case a 12 years old girl with CRMO arising with recurrent episodes of left supraorbital headache, followed by the appearance of a periorbital dyschromia. Magnetic resonance imaging (MRI) of the skull and orbits revealed an important subacute inflammatory process.