[Brodie's abscess, a pathology difficult to diagnose].

Introduction: Acute osteoarticular infections in children are rare pathologies, therefore early diagnosis and prompt treatment are crucial to avoid acute and long-term complications. Brodie's abscess (BA) is an un common type of subacute osteomyelitis, difficult to diagnose, so clinical suspicion is essential. Ob jective: To describe a case of Brodie's abscess and its etiological and clinical features.

Clinical case: A 14-year-old patient was seen at our clinic, who reported a one-month pain in the right thigh, with no history of fever or trauma. Physical examination revealed no volume increase, painful right hip range of motion, and increased sensitivity on superficial palpation of the right iliotibial band. X-rays where normal. Because of the pain persistence, an ultrasound was requested which showed a cortical irregularity. Magnetic resonance imaging (MRI) was performed and revealed a right femoral diaphysis, due to a possible bone tumor or an infectious process. Lab tests were normal. Biopsy and cultures were collected, identifying multi-sensitive Staphylococcus aureus. He was managed with debridement and intravenous antibiotics, responding positively.

Conclusions: The BA's clinical features and lab tests are unspecific, therefore the non-specialist physician should strongly suspect this pathology as a possible differential diagnosis in patients who persist with pain and present imaging alterations, even when there are no other symptoms or normal inflammatory parameters. A bone biopsy is essential for the differential diagnosis of tumor pathologies.