Mustafa Özdemir H.Yurtçu M.Ö?ün T.C.2020-03-262020-03-2620111300-0292https://dx.doi.org/10.5336/medsci.2009-14556https://hdl.handle.net/20.500.12395/27062Aneurysmal bone cyst (ABC) is a locally agressive tumor-like lesion of the bone. Sacral location is rare. Currently recommended treatment for a benign ABC lesion is complete intralesional curettage with or without selective arterial embolization and attempt to salvage unilateral sacral 2-5 roots. A 14-year-old girl presented with severe pain and a large mass in her lower lumbosacral region. Imaging studies demonstrated a destructive lesion, arising from the second sacral vertebral level, extending posteriorly and bilaterally into the gluteal muscles, and anteriorly into the pelvis. Open biopsy established the diagnosis of ABC. Marginal extra-capsular resection via a combined anterior and posterior approach, and postoperative radiation therapy were performed. The patient was pain-free, and no evidence of local recurrence was detected at the 84-month follow up postoperatively. Marginal extra-capsular resection and adjuvant radiotherapy are thought to be effective for the treatment of this large ABC of the sacrum. © 2010 by Türkiye Klinikleri.en10.5336/medsci.2009-14556info:eu-repo/semantics/openAccessAneurysmalBone cystsSacrumArticle31512881292Q4