[Acute obstructive renal failure secondary to retroperitoneal mass]

Area of Science:

• Nephrology
• Oncology
• Radiology

Background:

• Acute renal failure (ARF) is a critical condition often presenting in hospital settings.
• Pre-renal causes are common, but obstructive uropathy can also lead to ARF, particularly in older individuals.

Observation:

• A 67-year-old male presented with severe ARF (urea 199 mg/dl, creatinine 7.7 mg/dl) and hypertension.
• Initial sonography revealed bilateral hydronephrosis; however, a subsequent CT scan identified a periaortic retroperitoneal mass encasing both ureters as the obstruction source.
• Biopsy confirmed retroperitoneal fibrosis, with initial renal function showing 20% in the right kidney and 80% in the left.

Findings:

• Surgical intervention and bilateral "double J" catheterization provided temporary relief but did not resolve the underlying fibrosis.
• A 12-month course of tamoxifen (anti-estrogen) resulted in progressive reduction of the retroperitoneal mass, as evidenced by CT and MRI.
• Following tamoxifen treatment, complete disappearance of the fibrosis was confirmed by MRI, alongside gradual normalization of blood urea nitrogen and creatinine levels.

Implications:

• This case highlights tamoxifen as a potential therapeutic option for managing retroperitoneal fibrosis causing obstructive uropathy.
• Effective treatment of retroperitoneal fibrosis can lead to significant recovery of renal function and resolution of ARF.
• Multidisciplinary collaboration between nephrology, urology, and radiology is crucial for diagnosing and managing complex cases of ARF due to retroperitoneal masses.