Imaging mimics of chronic recurrent multifocal osteomyelitis: avoiding pitfalls in a diagnosis of exclusion

Chronic recurrent multifocal osteomyelitis (CRMO) is a pediatric autoinflammatory disorder that is characterized by multiple sterile inflammatory bone lesions with a relapsing and remitting course. CRMO belongs to the autoinflammatory family of rheumatologic disorders based on absence of significant titers of autoantibodies and autoreactive T-lymphocytes. In absence of pathognomonic clinical, radiographic or pathological features, diagnosis can be challenging. CRMO shares imaging features with other diseases. It is important for radiologists to be able to differentiate other diseases from CRMO because prognosis varies from completely benign to frankly malignant. In this article we first present the clinical and imaging features of CRMO to help readers gain an understanding of the disease process, then discuss our imaging approach to CRMO and review other disease processes that sometimes share similar imaging findings to CRMO and review differentiating features to help avoid misdiagnoses.