Presentation
Painful right upper arm. Previous radiographic diagnosis of NOF.
Patient Data
Large tubular cystic lesion in the proximal shaft and metaphysis of the right humerus. Predominant characteristics of a cyst with T2 hyperintense / T1 hypointense signal and absent enancement except for the distal end of the lesion, where there is solid hypovascular tissue, partly surrounded by rim sclerosis (adjacent to the lateral endosteal surface).
Case Discussion
In about one third of aneurysmal bone cyst, preexisting lesions can be identified, most commonly giant cell tumors. Non-ossifying fibroma belongs to the less commonly encountered, albeit well-documented precursors of ABCs1.