Imaging diagnosis of aneurysmal bone cyst secondary to giant cell tumor / 中华放射学杂志

ABSTRACT

Objective To improve recognition and imaging diagnosis of aneurysmal bone cyst secondary to a giant cell tumor.Methods To collect the dates of 12 patients with aneurysmal bone cyst secondary to a giant cell tumor were proved by operation and pathology from January 2003 to October 2006. Analyzed and summarized their imaging manifestations and correlation with pathohistology.Results Six lesions were located in epiphysis and metaphysic regions of long bone.Six lesions were located in pelvis.All cases showed a cystic lesion with expanded and osteolytic,eccentric 10 cases and centric 2 cases.Four cases display trabeculate,the margin is well define with a rim of bone sclerosis in 2 cases.Magnetic resonance imaging(MRI)scans were available in 10 patients.All case showed cystic,dilated lesions with solid areas. Eight cases manifested single or multitude solid nodules in big cystic wall.Two cases appeared solid masses with multitude cysts.The sign of multitude fluid-fluid level,best seen on T_2-weighted images,was present in all patients.Seven cases emerged soft-tissue masses.MR found indicative of large amounts of hemosiderin in one cases.Eight cases were examined by spiral CT with plain scanning and enhancement scanning. Reconstructed image were CTA and 3D-MPR(three dimensions multiplanar reconstruction)imaging.All cases showed cystic,dilated lesions with solid areas.The sign of multitude fluid-fluid level was present in 6 patients.The solid areas and cystic-wall of lesions showed contrast enhancement in 8 patients.3D-MPR imaging showed supply blood vessel of tumors in 3 cases.Arteriovenous malformation did not found in all patients.The surgeons'operative findings and the gross specimens were studied in all patients.All lesions were composed of solid areas and cystic areas.The diagnosis of pathology were ABC with GCT(grade Ⅱ)in 10 cases and ABC with GCT(grade Ⅲ).Conclusion Aneurysmai bone cyst secondary to a giant cell tumor is not rare.Adequately recognizing the pathologic basis of ABC,and selecting imaging techniques correctly (X-ray and MRI,or X-ray and CT)is especially important to diagnose a giant-cell tumor with secondary aneurysmai bone cyst.When an eccentric,expanded,lytic tumor with a cystic-solid lesion in epiphysis of long bone or pelvis shows multiple fluid levels,a giant-cell tumor with secondary aneurysmai bone cyst components should be sufficiently considered.