[Retrovesical pelvic masses: diagnosis]

We present two cases of pelvic masses with retrovesical localization: one consisting of a mature cystic teratoma and the other in a ganglionic metastasis of a subclinical prostate adenocarcinoma. We carry out an analysis of the clinical aspects as well as a review of the diagnostic guidelines to be followed in the light of the existence of a neoformation in this location. We analyse the possible differential diagnoses to be established with these tumours, which we should take into consideration despite their rare incidence and form of presentation.