Popliteal venous aneurysm mimicking a soft tissue tumour. A case report.

A case of a giant, thrombosed popliteal venous aneurysm without pulmonary embolism in a 53-year-old woman is reported. Despite thorough preoperative investigation including ultrasound and magnetic resonance imaging, this was misdiagnosed as a benign soft tissue tumour. During the operation the thrombosed venous aneurysm was resected and a vein graft from the contralateral saphenous vein was interposed. Popliteal venous aneurysm is a rare entity, presenting occasionally with local signs and symptoms and more often with pulmonary embolism. The clinician should therefore keep this in mind whenever dealing with a large, soft tissue popliteal fossa mass or looking for the cause of recurrent pulmonary embolism.