There is a large well-defined proximal tibial diaphysis and metaphysis heterogeneous signal intensity mass lesion. Appears hypointense on T1WI and hyperintense on T2WI associated with bone marrow edema more distally in the diaphysis.
Bone expansion is noted more on the lateral side, with remarkable cortical thinning is seen posteriorly, laterally, and proximally with interruption seen anteriorly extending into the chondral tissue of tibial tuberosity without soft tissue component.
A small linear signal is seen arising from the upper part of the mass lesion extending close to the growth plate, better seen on sagittal gradient-echo images.
It measures around six by three by three centimeters respectively in maximal craniocaudal, transverse, and anteroposterior dimensions.
Soft tissue edema is noted also more distally.
The fibular, tibial epiphysis, and distal femur appear normal.
No significant knee joint fluid.
No evidence of neurovascular bundle invasion.
Impression:
- MRI findings are due to the known bone tumor (Chondromyxoid fibroma).