Unusual appearance of retroperitoneal fibrosis simulating a tumour.

Retroperitoneal fibrosis (RPF) is an uncommon entity that usually presents as a fibrous plaque-like lesion that encases the aorta and inferior vena cava below the level of the renal arteries. We present an unusual mass-like appearance of this disease simulating a tumour, with foci of calcification, seen in a young girl.