Clinicopathological features of retroperitoneal tumours.

The clinicopathological features of 49 neoplasms in the retroperitoneum, but not arising directly from a major retroperitoneal organ, are described. Abdominal pain and a mass, urinary tract symptoms and evidence of pressure on venous channels or nerves were common modes of presentation. In 6 cases the neoplasms were found incidentally and in 4 patients removal of the retroperitoneal mass was an elective procedure during the treatment of metastatic testicular germ cell tumour. Histopathological diagnosis revealed 4 major tumour types: germ cell neoplasms, non-germ cell metastatic carcinoma, soft tissue sarcoma and lymphoma. The differential diagnoses are discussed. A knowledge of the neoplasms to be expected in this site may indicate which pre-operative investigations should be undertaken.