Presentation
Known familial Mediterranean fever, complaining of abdominal and back pain.
Patient Data
A large amalgamated retroperitoneal periaortic soft tissue mass/sheet-like lesion. It is seen encasing the aorta and both common iliac arteries, associated with mild compression, yet no evidence of significant stenosis.
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.
Case Discussion
A known case of familial Mediterranean fever, presented with retroperitoneal periaortic soft tissue mass/sheet-like lesion, that was found to be retroperitoneal fibrosis.
There are two types:
-
primary (idiopathic): 2/3 of cases
a manifestation of systemic autoimmune or inflammatory diseases
-
secondary: 1/3 of cases
most commonly due to medications, neoplasms
FDG PET-CT
not useful as a primary diagnostic tool due to low specificity
allows detection of remote sites of disease
may help guide biopsy and assess treatment response
Top differential diagnoses
retroperitoneal metastases and lymphoma
coagulopathic ("retroperitoneal") hemorrhage