MRI - Leg
Well-defined multi-lobulated mass replaces the proximal fibula and invades the cortex of the lateral tibial plateau with extension into the lateral knee joint space. The mass demonstrates heterogeneous signal intensity which is predominantly isointense to muscle on T1W and hyperintense on T2W imaging. The mass displaces and abuts the popliteal artery which has an irregular outline. The peroneal nerve is displaced and encased laterally.