[Popliteal venous thrombosis associated with a false aneurysm revealing femoral exostosis in a child].

Recent unprovoked and symptomatic thrombosis of the left popliteal vein was diagnosed in a 9-year-old girl. Treatment with low-molecular-weight heparin was initiated in association with vitamin K antagonist (INR 2.5), and compressive stockings. Two and a half months later, the ultrasound examination revealed a false aneurysm of the left distal superficial femoral artery. Knee X-rays showed a distal femoral exostosis. MRI clarified the relationship between the false aneurysm and the exostosis. Bone scintigraphy eliminated multiple exostoses. Resection of the false aneurysm associated with end-to-end femoro-popliteal saphenous bypass and exostosectomy in the same operative time were performed. On histopathological examination there was no sign of malignant transformation. Vascular complications of exostoses are infrequent and the association with deep venous thrombosis and false aneurysm is exceptional. This case report illustrates the contribution of knee X-rays to unravel this unusual clinical presentation.