[Aggressive aneurysmal bone cyst of the humerus in a child].

A 9-year-old child presented an aggressive aneurysmal bone cyst of the humerus. Despite multiple treatments (intracystic steroid injections, curettage, Ethibloc injection), the lesion continued to progress. Surgical treatment was undertaken at the age of 19 years and enabled total tumor resection associated with reconstruction with a vascularized fibular flap. Five years later, the patient was free of recurrence. The graft was well integrated and shoulder function was normal. We present the diagnostic difficulties encountered in this case and discuss the therapeutic options. Biopsy is indispensable before instituting treatment.