Aneurysmal bone cyst--clinical and morphological aspects.

AIM To assess the results of surgical treatment in aneurysmal bone cysts. MATERIALS AND METHODS 31 patients with aneurysmal bone cysts underwent surgical treatment in our department. In almost half of cases, the lesion was located in the femur. In 12 cases, a pathological bone fracture was the first clinical sign. The treatment consisted in curettage, abrasion of the cavity inner walls using a motorized burr and filling with morsellized bone grafts (autografts ± allografts) or bone substitutes (four cases). Microscopically, the diagnosis relies on cystic spaces filled with blood, divided by fibrous septae consisting in immature bone trabeculae, hemosiderin filled macrophages and fibroblasts. We performed multiple bioptic probes from different levels of the lesion. RESULTS Macroscopically, the osseous lesion appeared as a multi-loculated blood-filled cavity (cavities separated by septa) in 30 (96.77%) cases and as a solid tumor in one (3.23%) case. At 12 months after surgery, grafts osteointegration was present in 24 cases. At an average follow-up time of six years and four months, refilling with bone grafts was necessary in two cases and no local recurrence was observed. CONCLUSIONS Aneurysmal bone cyst is most frequent in the second decade of age. Its prevalence in female gender is double compared to the male gender. The positive diagnosis relies on the histopathological examination. Because of the strong relationship with a number of precursor lesions (giant cell tumor, fibrous dysplasia, non-ossifying fibroma, chondroblastoma, osteoblastoma) multiple bioptic probings are mandatory, in order to diagnose, if possible, a primary lesion, which may modify the therapeutic attitude. Treatment by curettage, abrasion of the cavity inner walls and filling with morsellized grafts has very good results. The risk of recurrence is very low.