[Neuroendocrine tumor in a horseshoe kidney: relative risk of association of two related entities].

Objective: Primary renal neuroendocrine tumor (NET) is a very rare neoplasia with a higher frequency of appearance in horseshoe kidney (HK). From 1966, when Resnick published the first case, approximately 2 of each 10 new cases appear in kidneys with this malformation. From the diagnosis of a case of primary NET in a HK, we calculated the relative risk of their presentation as associated entities.