Pseudoaneurysm of the dorsalis pedis artery is an uncommon condition that is usually caused by a traumatic injury or iatrogenic intervention. When it presents as a nonpulsatile soft tissue mass without a specific antecedent event, it can introduce a difficult diagnostic dllemma. This report describes an unusual case of an idiopathic pseudoaneurysm of the dorsalis pedis artery that mimicked pigmented villonodular synovitis (PVNS).
A 67-year-old man presented with swelling on the dorsum of his foot that had been present for 2 months. The nonspecific mass was slowly enlarging and painful. Pain was worse after activity and at the end of the day. There was some relief with elevation, but the foot always remained more swollen than the other side. The patient reported suffering an ankle fracture on the same side 20 years earlier, but he specifically denied any recent history of trauma or injury to the foot. He denied any increase in activity or change in lifestyle. Past medical history was unremarkable; he did not have diabetes mellitus, heart disease, or peripheral vascular disease.