Presentation
Presenting with knee complaints.
Patient Data
Largely extra-cortical lesion with cortical irregularity on the dorso-medial aspect of the distal femur. The lesion is iso-intense on T1 and hyperintense on T2 and fat sat sequences. Thick tendons from the adductor magnus muscle and medial head of the gastrocnemius can be seen attaching to the area of the lesion. A typical non ossifying fibroma (NOF) is seen subcortically in the dorso-lateral femur.
Case Discussion
The co-existence of a non-ossifying fibroma and a cortical desmoid in this patient serves to highlight the differences between these two benign lesions. The characteristic location of the cortical desmoid, on the dorsomedial aspect of the distal femur (the attachment of the adductor magnus or medial head of gastrocnemius) is also well illustrated in this patient. The age and the incidental detection (asymptomatic) of the lesion are also typical.