[Testicular adrenal rests tumor: a difficult diagnosis].

This paper presents the case of a 19 year old patient with a well defined under palpation testicular tumor where surgical examination allowed a simple enucleation. Histological analysis during the operation reported it as a Leydig cells tumor but definitive analysis indicated tumor by adrenal residues. This histological argument illustrates the difficulty of making a differential diagnosis between both tumors, difficulty that goes beyond morphological and even clinical appreciation.