[Tumors of the retroperitoneum].

Most of the retroperitoneal tumors (not originating from organs) are extremely rare (0.1% of all tumors) and are malignant. Clinical signs occur only late, are non-specific and are related to extreme tumor size. The most frequent tumors are malignant fibrous histiocytoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, hemangiopericytoma and neurogenic… (More)