Calcified retroperitoneal fibroma.

A case of 31-year-old male with a retroperitoneal tumor is described. Abdominal ultrasound revealed a left para-aortic calcific mass, adjacent to the left lobe of the liver and to the upper pole of the left kidney. A CT-scan of the abdomen showed the mass to originate from the left adrenal gland. At operation, a large, retroperitoneal mass, adherent to the left kidney and the spleen, but not infiltrating, was excised. Histologically the tumor was diagnosed as a calcified osteo-producing fibroma. Benign retroperitoneal tumors represent about 25% of all retroperitoneal neoplasm. This reported case represents a retroperitoneal tumor of slow growth and benign clinical course whose characteristic consists of the heavy calcifications which are normally absent in a fibroma type mass.