RESUMO
Retroperitoneal fibrosis (RPF) is a rare condition characterized by systemic inflammation and the proliferation of fibroinflammatory tissues in the retroperitoneum. It may lead to the formation of a retroperitoneal mass and can encase the aorta, its branches and ureters. The pathogenesis of RPF is not fully known. We report a case of a 52-year-old male presented with low back ache, flank pain, swelling of legs, oliguria and features of obstructive uropathy, later diagnosed to be RPF. The mainstay of diagnosis includes blood workup, imaging and biopsy. The first line of treatment is corticosteroids. Surgical intervention is carried out when medical measures have failed or when contraindicated. Early diagnosis and prevention of complications is the key, and a high degree of suspicion is needed.