Three months after splenic infarct, a 50-year-old woman underwent arte
riography for persistent low-grade fever and abdominal complaints. Aft
er 5 months of corticosteroid therapy for ''polyarteritis nadosa,'' an
other arteriogram confirmed embolic disease; transesophageal echocardi
ography (TEE) showed a pedunculated mobile thrombus in the aortic arch
. We suggest this represents ''pseudovasculitis'' from an aortic throm
bus.