There is extensive marrow abnormality of the left tibia, consisting of multiple confluent nodules. A few small satellite nodules also lie in the lateral tibial plateau in a subchondral location. The nodules vary slightly in the degree of signal intensity, but all have low T1 and high T2, with enhancement. The findings result in expansion of the medullary cavity and thinning of the overlying cortex, in keeping with a long-standing process. In addition, there is some bowing of the proximal tibia. No cortical breach, pathological fracture, extra-osseous soft tissue component or region suspicious for malignant transformation is appreciated. No soft tissue inflammatory change.
Conclusion: Appearances compatible with the known diagnosis of fibrous dysplasia.