Presentation
Palpable painless lump at the right upper calf. The x-rays are not available.
Patient Data
Pedunculated bony mass arising from the posterior aspect of the proximal tibial metaphysis and projecting away from the epiphysis. The medullary cavity, as well as the cortex of the bony lesion, are in continuity with those of the parent bone.
The cartilage cap is well-demonstrated on PD fat sequences and measures less than 3 mm in thickness in this case. The distal component of the bony lesion protrudes into the adjacent popliteus and plantaris muscles. No pathological fracture or adjacent soft tissue mass is seen.
Case Discussion
MRI features of pedunculated osteochondroma of the proximal tibia, which is considered the second most common location (15-20%), after the femur (30%).