Chronic Recurrent Multifocal Osteomyelitis Demonstrated by Tc-99m Methylene Diphosphonate Bone Scan

A 12-year-old Middle Eastern girl presented with abdominal pain, weight loss, and intermittent pain in both thighs. She was initially suspected of Crohn disease, but this diagnosis was excluded after extensive gastromedical evaluation. Plain x-rays of the femora were normal, whereas the initial Tc-99m methylene diphosphonate (MDP) bone scan showed several foci with increased activity in both femurs. MR scan showed excessive periostal inflammatory and mild intramedullary changes in both femurs. A percutaneous bone biopsy demonstrated changes consistent with chronic recurrent multifocal osteomyelitis (CRMO). The patient's symptoms disappeared spontaneously, but reappeared 1.5 years later, which led to a new MDP bone scan that showed normal findings.