title: [Retroperitoneal tumors].
abstract: BACKGROUND
  Retroperitoneal tumors are rare malignancies. The retroperitoneum can host a wide spectrum of pathologies including primary or metastatic lesions.
  
  
  OBJECTIVE
  Treatment of retroperitoneal tumors is often associated with several challenges because of their relative late presentation and anatomic location.
  
  
  METHODS
  Because of various pathologies, a detailed case history, laboratory investigation and ultrasound should be performed. Radiologic examinations remain a major component in the diagnosis. In addition to computed tomography, magnetic resonance imaging and positron emission tomography are used. Although radiologic findings are often unspecific, there are often typical findings such as dissemination, margins, vascularization and tumor texture which contribute to the differential diagnosis even before making a definitive diagnosis. Due to the complexity of primary retroperitoneal tumors, which require different treatments depending on the final diagnosis, the treatment approach should be determined in a multidisciplinary tumor conference prior to histological confirmation and initiation of treatment.
  
  
  CONCLUSIONS
  To ensure the best potential curative treatment modality for retroperitoneal tumors, treatment is best performed in high-volume centers by a multidisciplinary team.
authors.affiliation: Medizinische Klinik 1, Abteilung für Onkologie und Palliativmedizin, HELIOS Universitätsklinikum Wuppertal, Heusnerstraße 40, 42283, Wuppertal, Deutschland. Oliver.Schmalz@helios-kliniken.de.
authors.forename: O
authors.initials: O
authors.lastname: Schmalz
mesh_terms: D003937:Diagnosis, Differential; D019317:Evidence-Based Medicine; D006801:Humans; D012186:Retroperitoneal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
keywords: Germ cell tumor; Lymphoma; Metastasis; Neoplasms, retroperitoneal; Sarcoma