Fibromatosis--a rare retroperitoneal tumour.

A case of retroperitoneal fibromatosis in a 28-year-old white male is presented. The soft tissue tumor, with a weight of 8000 g, was resected by laparotomy. Because of adhesions to the ascending colon and the right ureter, a hemicolectomy and partial resection of the right ureter had to be performed additionally. Intraabdominal fibromatoses are very infrequent tumorous lesions of the connective tissue, occurring retroperitoneally only in isolated cases. Their etiology is presumed to be a hereditary or gene-associated defect in the regulation of connective tissue growth. In addition, trauma and hormonal influences often appear as inductive cofactors.