Presentation
Left thigh pain with subjective sensation of muscle being “caught” during exercise.
Patient Data
X-ray of femur demonstrates pedunculated mass arising from the lateral aspect of the distal femoral metaphysis.
MRI of left femur with contrast demonstrates pedunculated mass arising from the lateral aspect of the distal femoral metaphysis. The exophytic lesion extends proximally with continuity of the cortex and medulla. Less concerning for malignant transformation given that cartilage cap is < 1.5 cm.
Histology
This patient had surgical resection of the lesion.
Surgical pathology diagnosis: Left distal femur lesion, excision: consistent with osteochondroma. No malignancy identified.
Case Discussion
This pedunculated mass arising from the lateral aspect of the distal femoral metaphysis is typical of osteochondromas of the knee.