Patient History: 26-yo female with left hip sprain.
Findings
SKELETAL: Abnormal fat and water-weighted signal within the left femur from the proximal diaphysis through the intertrochanteric region into the femoral neck, with infiltration and mass-like soft tissue in the surrounding periosteum and musculature. Cortical breakthrough at the medial aspect of the proximal left femur just anterior to the lesser trochanter. No unstable fracture. Bone island in the right ischium.
PELVIS: No free fluid. No hernia. No lymphadenopathy.
JOINTS: Normal joint spaces.
ACETABULUM/LABRUM: Normal.
MUSCLES/TENDONS/LIGAMENTS: Intact tendons. No muscle tear.
OTHER/SOFT TISSUE: No lymphadenopathy.
Conclusion
Infiltrative destructive lesion within the left femur with infiltration of the surrounding soft tissues. Ill-defined zone of transition. Cortical breakthrough anteromedial to the proximal femur just anterior to the lesser trochanter. No pathologic or unstable fracture. Differential diagnostic considerations include Ewing’s tumor of adult, eosinophilic granuloma, chondromyxoid fibroma; osteoid producing lesion felt less likely given lack of low signal/bony matrix. Correlate with plain radiograph or CT to further evaluate matrix.
