Spontaneous regression of aneurysmal bone cyst. A case report.

Generally, aneurysmal bone cyst is considered to be a benign lesion that occurs rarely. Its etiology and treatment vary considerably, but curettage and grafting is the widely accepted treatment. Due to the nature of the disease recurrence is always expected. It rarely regresses and we report here a case that showed an improvement spontaneously after open biopsy. Follow-up for more than 4 years has shown no progression.