Presentation
Fall from the stairs and contusion in the right knee.
Patient Data
Large heterogeneous lytic lesion, geographic, eccentric with sclerotic edges and a small transition zone, balooning and no periosteal reaction is identified; located in the distal metaphysis of the right femur with extension towards the epiphysis.
The lytic component of the lesion is confirmed.
Hypointense component on T1 and heterogeneously hyperintense on FS-PD and T2 with pseudolobular appearance, molding of the growth plate and extension towards retrofemoral soft tissues without involvement of the neurovascular bundle. It presents peripheral and scarcely central enhancement. Secondary edema of the femoral condyles. There are no alterations in muscles, patella, cartilage, menisci, tendons or ligaments.
Case Discussion
This patient had a knee injury and as an incidental finding on radiography, a geographical lesion with a lytic appearance and benign characteristics was discovered. It was decided to perform CT scan that corroborated the lytic characteristics of the tumor.
MRI showed a tumor with a pseudolobular appearance, heterogeneously hyperintense on FS-PD and T2 with little enhancement.
Age, location and imaging characteristics of this patient suggest a giant cell tumor and chondromyxoid fibroma, however, the biopsy revealed the first possibility.