[Therapy of aneurysmal bone cyst]

The aneurysmal bone cyst represents a tumor-like lesion, which does not occur frequently. Every site of the skeleton may be involved. Although it can be observed at any age, it distinctly predominates from 10 to 20 years of age. Distinction of aneurysmatic bone cysts from certain benign or malignant bone tumours requires subtle imaging techniques and an experienced bone tumour pathologist. Since the lesion shows a heterogeneous biological behaviour and typically occurs in the growing skeleton, a wide range of surgical procedures must be provided concerning tumour resection and defect reconstruction. In the current retrospective study results of 41 surgically treated aneurysmal bone cysts, thereof 5 latent, 31 active, and 5 aggressive lesions, were investigated. While morbidity due to the therapeutic measures was comparatively low even in extended lesions and demanding reconstructions, a recurrence rate of 19.5% had to be observed in our series. Taking into consideration the biological activity of the lesion, analysis of the recurrences revealed inappropriate surgical margins had been chosen at the primary operation in all of these patients. Since the risk of a local relapse is linked both to aggressiveness of the primary lesion and to surgical radicality, therapy of aneurysmal bone cyst requires preoperative staging and stage-dependent surgical procedures.