[Retroperitoneal liposarcoma--contribution to differential diagnostic problems of primary retroperitoneal tumors].

The primary retroperitoneal tumours-a rare, but histologically very extensive group of above all malignant tumours-only late appear with their symptoms. Though with the help of the modern radiological investigation methods the proof of a tumour is frequently successful, so in special cases a coordination to organs may make great difficulties also when the total diagnostic spectre is used. These problems shall be shown by the demonstration of a case report.