Can FDG-PET-CT differentiate between a malignant and benign RPF?
No, not useful as a primary diagnostic tool due to low specificity.
What are the differential diagnoses?
Chronic periaortitis, retroperitoneal metastases and lymphoma, coagulopathic ("retroperitoneal") haemorrhage and inflammatory abdominal aortic aneurysms.
FDG-PET confirms the mass lesion, showing a large metabolically active amalgamated retroperitoneal para-aortic soft tissue mass/sheet-like lesion, with maximum SUV 11.7.