Retroperitoneal Fibrosis: Radiological-pathological Features

42 yrs male presented to general physician with complaints of progressive symptoms of lower backache, fatigue, anemia, weight loss and mild fever. Initial diagnosis on clinical grounds was abdominal tuberculosis but on ultrasonography a hypo echoic mass encircling the aorta, IVC and ureters at the aortic bifurcation was observed with associated mild bilateral hydroureteronephrosis. His ESR & C-RP level was raised. Retroperitoneal fibrosis (RPF) was suspected and contrast enhanced CT scans was performed. To differentiate between Retroperitoneal fibrosis and lymphoma CT guided biopsy carried out that confirmed our top impression on USG and CT of Retroperitoneal fibrosis. Histology examination showed infiltration of plasma cells, macrophages, lymphocytes and eosinophils accompanied by fibrosis.