Low PET uptake may mask aortic sarcoma

Recurrent arterial embolization prompted surgery after imaging suggested thrombus, but definitive pathology revealed malignancy.

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A 69-year-old man had an aortic mass with renal and splenic infarctions and later developed popliteal artery occlusion despite anticoagulation.
2

Preoperative FDG-PET showed minimal uptake, with a maximum standardized uptake value of 3.1, favoring thrombus over malignancy.
3

The gelatinous, well-circumscribed mass resembled a benign myxoma during surgery, and frozen section supported that preliminary diagnosis.
4

Definitive pathology identified myxoid intimal sarcoma; MDM2 amplification was confirmed in the aortic tumor and an embolized fragment.
5

The patient declined recommended adjuvant anthracycline-based chemotherapy, developed progressive weight loss and ascites, and died 159 days after surgery.

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