title: Soft tissue aneurysmal bone cyst.
abstract: A soft tissue aneurysmal bone cyst located in the right gluteus medius of a 21-year-old man is reported. On conventional radiography, the lesion demonstrated a spherically trabeculated mass with a calcific rim. On CT scan, it showed a well-organized peripheral calcification resembling a myositis ossificans. On MRI, it presented as a multilocular, cystic lesion with fluid-fluid levels. The lesion had no solid components except for intralesional septa. Although findings on imaging and histology were identical to those described in classical aneurysmal bone cyst, diagnosis was delayed because of lack of knowledge of this entity and its resemblance to the more familiar post-traumatic heterotopic ossification (myositis ossificans).
authors.affiliation: Department of Radiology, Universitair Ziekenhuis Antwerpen (University of Antwerp), Wilrijkstraat 10, 2650, Edegem, Belgium.
authors.forename: X L
authors.initials: XL
authors.lastname: Wang
authors.forename: J L
authors.initials: JL
authors.lastname: Gielen
authors.forename: R
authors.initials: R
authors.lastname: Salgado
authors.forename: F
authors.initials: F
authors.lastname: Delrue
authors.forename: A M A
authors.initials: AM
authors.lastname: De Schepper
mesh_terms: D000328:Adult; D017824:Bone Cysts, Aneurysmal / Q000175:diagnosis* / Q000473:pathology; D002081:Buttocks; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology; D009135:Muscular Diseases / Q000175:diagnosis* / Q000473:pathology; D014057:Tomography, X-Ray Computed