Abstract
Retroperitoneal fibrosis (RPF) is a rare disease with a nonspecific presentation. RPF can be classified into Idiopathic, the most common, or secondary due to malignancy and various medications resulting in chronic inflammation and fibrosis in the retroperitoneum. The complications arise due to the compression of structures in the retroperitoneum. The most common presentations are constitutional symptoms, abdominal pain, and renal insufficiency due to ureteral obstruction. Venous thrombosis or claudication on presentation is rare. Diagnosis and treatment remain challenging due to the lack of standard diagnostic or treatment protocols. Our patient presented with symptoms of acute deep vein thrombosis (DVT) with varices on the abdomen and mild bilateral hydronephrosis. A CT scan revealed a retroperitoneal mass, which was confirmed to be RPF by biopsy. Relevant laboratory tests, including IgG4, were negative. High-dose corticosteroid therapy reduced the inflammatory markers and the size of the retroperitoneal mass.