Femur ostochondroma and secondary pseudoaneurysm of the popliteal artery.

Osteochondroma is the most common skeletal benign tumour. It may present in a solitary form or as part of an autosomal dominant hereditary syndrome affecting several bones simultaneously. It is found most often in the knee region. It is generally asymptomatic although it may cause complications, including vascular disorders. In view of anatomical circumstances, the popliteal artery is most frequently involved in this type of complication. This is a case report of a 9-year-old boy who referred with pain in the distal third of his femur. Osteochondroma was initially diagnosed through plain X-ray. In view of worsening symptoms, an ultrasound and magnetic resonance imaging were performed and the patient was diagnosed with pseudoaneurysm of the popliteal artery.