EULAR Imaging Course, 30 March- 1 April, Lisbon CT images of the skull Differential diagnosis: Paget disease and aneurysmal bone cyst Nikolett Marton MD Trainee in radiology: Jahn Ferenc Hospital, Budapest, Hungary PhD student: Semmelweis University, Budapest, Hungary EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Acute non-contrast-enhanced computed tomography of the skull Transverse (axial) plane, Bone window Elderly patient with the possibility of acute intracranial hemorrhage Paget or not Paget? Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images 2 short case reports which helped to decide about the diagnosis: (both >70 yrs old patients, examined to exclude the possibility of acute cerebral hemorrhage) EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Acute non-contrast-enhanced computed tomography of the skull Transverse (axial) plane, Bone window 80 yo female Cause of examination: intracranial hemorrhage? Incidental finding: Paget disease of the skull Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Paget disease of the skull: Osteoporosis circumscripta: large, well-defined lytic lesion Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CTimages Paget disease of the skull: cotton wool appearance:  mixed lytic and sclerotic lesions of the skull Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Paget disease of the skull: diploic widening: both inner and outer calvarial tables are involved, with the former usually more extensively affected Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Paget disease of the skull: Tam o'Shanter sign: frontal bone enlargement, with the appearance of the skull falling over the facial bones, like a Tam o' Shanter hat Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Acute non-contrast-enhanced computed tomography of the skull Transverse (axial) plane, Bone window 80 yo female Cause of examination: intracranial hemorrhage? Aneurysmal bone cyst of the skull Mediworld Plus Kft. Hungary EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Aneurysmal bone cyst: Sharply defined, expansile osteolytic lesions, with thin sclerotic margins. No cotton wool sign! No general diploic widening! Benign expansile tumour-like bone lesions of uncertain aetiology, composed of numerous blood filled channels, and mostly diagnosed in children and adolescents. Epidemiology: they are primarily seen in children and adolescents –> Not an incidental finding on mature patients’ skull CT. Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

N Marton Budapest, Hungary CT images Acute non-contrast-enhanced computed tomography of the skull Transverse (axial) plane, Bone window Sharply defined, expansile osteolytic (cavitated) lesions, with thin sclerotic margins of the right parietal and frontal (including the orbital region) bones. 70 yo male Cause of examination: intracranial hemorrhage? Aneurysmal bone cyst of the skull Radiopaedia.com EULAR Imaging Course, 30 March- 1 April, Lisbon

Thank you for your kind attention! N Marton Budapest, Hungary CT images Thank you for your kind attention! Egill Skallagrímsson: The famous viking warrior suffered from Paget disease Headstuff.org EULAR Imaging Course, 30 March- 1 April, Lisbon