To describe diagnostic challenges and clinical course in a patient with myxoid aortic intimal sarcoma.
Approach:
Case: A 69-year-old man with abdominal pain had an aortic intraluminal mass and kidney and spleen embolic infarctions on computed tomography.
Evaluation: Assessment included FDG-PET, surgery, histopathology, immunohistochemistry, and molecular testing.
Key Findings:
FDG-PET showed minimal uptake (maximum standardized uptake value 3.1), favoring thrombus; the gelatinous mass also appeared benign during surgery, and frozen section suggested myxoma.
Despite anticoagulation, the patient developed a left popliteal artery occlusion attributed to embolization.
Definitive pathology identified myxoid intimal sarcoma. The tumor was positive for MDM2, CDK4, and FLI-1, with a Ki-67 index of 50%; fluorescence in situ hybridization confirmed MDM2 amplification in the primary tumor and an embolized fragment.
After gross resection and aortic graft replacement, microscopic margin assessment was not feasible. The patient declined recommended anthracycline-based chemotherapy, developed weight loss and ascites suggestive of metastasis, and died 159 days after surgery.
Interpretation:
The authors noted that myxoid tumors’ high water content and low cellularity may contribute to low FDG uptake and that their gelatinous appearance can resemble benign myxoma. They advised maintaining suspicion for malignancy in aortic masses with recurrent embolic complications despite apparently benign imaging.
Limitations:
A single-patient case report cannot establish how often diagnostic misclassification occurs or the accuracy of individual tests.
The proposed use of MDM2/CDK4 immunohistochemistry and molecular testing requires validation in larger case series.
The case cannot establish whether earlier diagnosis or additional treatment would have improved survival.
Conclusion:
This case illustrates that low PET uptake and benign-appearing features did not exclude aortic intimal sarcoma.
A large international randomized trial found fewer postoperative pulmonary complications with sugammadex vs. neostigmine following major abdominal or thoracic surgery, although the difference was driven primarily by reduced atelectasis.
