[Retroperitoneal paraganglioma. Infrequent pathology].

Presentation of 3 cases of retroperitoneal paraganglioma non pre-operatively diagnosed: one dependent of the Zuckerkandl's organ with ultrasound examination showing a panelled cystic mass, and two located in the renal parahilar area, all accidental findings during renal surgery. Lack of appropriate pre-operative background and diagnosis produced a hypertensive crisis in one patient during removal manoeuvres which was entirely controlled. After a 4-, 2- and 1-year follow-up, respectively, patients remain asymptomatic and disease-free. An analysis of the most relevant features in these retroperitoneal tumorations was carried out from a clinical, diagnostic, therapeutic and prognostic point of view.