title: Clear cell chondrosarcoma with secondary aneurysmal bone cyst changes.
abstract: Clear cell chondrosarcoma is a rare cartilaginous tumour of low-grade malignancy. Although it has a characteristic histological appearance, its radiological features and clinical presentation often mimic a benign lesion. Herein, we describe the case of a patient with a clear cell chondrosarcoma of the right proximal femur that had an atypical appearance of chronic avascular necrosis on initial plain radiographs, which made preoperative diagnosis a challenge. In addition, the tumour also had extensive areas of aneurysmal bone cyst-like changes, which is not only a rare histologic phenomenon in clear cell chondrosarcoma, but also a confounding factor in the interpretation of the radiologic findings.
authors.affiliation: Department of Pathology, Singapore General Hospital, 20 College Road, Level 10, Diagnostics Tower, The Academia, Singapore 169856. timothy.tay@mohh.com.sg.
authors.forename: Timothy
authors.initials: T
authors.lastname: Tay
authors.forename: Steven Bak Siew
authors.initials: SB
authors.lastname: Wong
authors.forename: Kesavan so
authors.initials: Ks
authors.lastname: Sittampalam
authors.forename: Denny Tjiauw Tjoen
authors.initials: DT
authors.lastname: Lie
mesh_terms: D000328:Adult; D017824:Bone Cysts, Aneurysmal / Q000150:complications* / Q000000981:diagnostic imaging; D001859:Bone Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging; D002813:Chondrosarcoma / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000473:pathology; D006615:Hip / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D009336:Necrosis / Q000473:pathology; D010003:Osteoarthritis / Q000000981:diagnostic imaging; D011859:Radiography; D051598:Whole Body Imaging