Rind-like Perirenal Soft-Tissue Masses

Rind-like perirenal soft tissue masses: Retroperitoneal fibrosis

Differential diagnosis for rind-like perirenal soft-tissue masses:

• Lymphoma (and Waldenstrom Macroglobulinemia)
  • Usually due to contiguous spread from retroperitoneal or renal lymphoma: Distinct imaging patterns: multiple masses, solitary mass, diffuse infiltrating mass, rindlike soft-tissue thickening, and direct invasion from adjacent retroperitoneal lymphadenopathy
  • Isolated perirenal lymphoma very unusual (<10% of cases): Uniformly attenuating rindlike soft-tissue mass.
  • Does not necessarily affect renal function.
• Erdheim-Chester disease
  • Rindlike soft-tissue lesions surrounding the kidneys and ureters
  • Severe compression of renal parenchyma and ureters leads to progressive renal failure
  • Percutaneous nephrostomy made difficult because due to fibrous perinephritis.
• Retroperitoneal Fibrosis (shown above)
  • Typically localized to infrarenal aorta and common iliac arteries
  • Isolated or related to multifocal fibrosclerosis (may include autoimmune pancreatitis, sclerosing cholangitis, scleroderma, Riedel thyroiditis, fibrotic pseudotumor of the orbit, and fibrosis involving multiple organ systems).
  • Perirenal involvement can be from extension from retroperitoneal fibrosis, without associated retroperitoneal fibrosis, or one of manifestations of multifocal fibrosclerosis
  • Perirenal involvement: Soft-tissue mass enveloping kidneys without displacing them.

References

Surabhi VR, Menias C, Prasad SR, Patel AH, Nagar A, Dalrymple NC. Neoplastic and non-neoplastic proliferative disorders of the perirenal space: cross-sectional imaging findings. Radiographics. 2008 Jul-Aug;28(4):1005-17.