title: [Non-secreting, extra-adrenal retroperitoneal paragangliomas].
abstract: OBJECTIVE
  Two cases of extra-adrenal non-secretory retroperitoneal paraganglioma in male patients are presented. The first case had intermittent vascular claudication in lower limbs and the second one was an incidental finding during staging of a lymphoma.
  
  
  METHODS
  Both cases were studied using imaging techniques (US, CT and MRI) and histological and immunohistochemical analyses.
  
  
  RESULTS
  The imaging techniques demonstrated solid homogeneous retroperitoneal masses intimately adhered to the abdominal aorta in the first case and located in the left upper hemiabdomen (in front of the left kidney) in the second one. Histological analysis showed a proliferation of spindle cells with cuboid cytoplasm arranged in solid nests, with typical immunohistochemical findings of paraganglioma.
  
  
  CONCLUSIONS
  Extra-adrenal retroperitoneal paraganglioma are rare tumors, particularly the non-secretory variant. The only reliable criteria for malignancy are extensive capsular invasion and distant metastases.
authors.affiliation: Servicio de Anatomía Patológica, Hospital Nuestra Señora de Covadonga (Hospital Central de Asturias), Oviedo, España. alejovara@arrakis.es
authors.forename: Beatriz
authors.initials: B
authors.lastname: Madrigal Rubiales
authors.forename: Alejandro
authors.initials: A
authors.lastname: Vara Castrodeza
authors.forename: Manuel
authors.initials: M
authors.lastname: Fresno Forcelledo
authors.forename: Pilar
authors.initials: P
authors.lastname: Ablanedo Ablanedo
mesh_terms: D000368:Aged; D003251:Constriction, Pathologic / Q000209:etiology; D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary; D010235:Paraganglioma / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D012186:Retroperitoneal Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D014682:Vena Cava, Inferior