Primary umbilical endometriosis (Villar's nodule) - case study, literature revision.

Spontaneous umbilical endometriosis, also known as Villar's nodule, is an unusual location of the endometrial tissue.Whilst in the case of umbilical locations secondary to surgical procedures endometriosis occurs quite frequently,the frequency of the primary umbilical location is lower than 1% of all endometriosis locations. The authors present such a case diagnosed in a young, nulliparous patient with no history of surgical procedures, the diagnosis being suggested by the presence of an umbilical tumor mass whose symptomatology concurs with menstrual periods. The aspects regarding differential diagnosis and the therapeuticoptions for the surgical cure of this type of lesion are discussed.