[Three cases of urachal cyst in adults].

The urachus is a thick fibrous cord that appears in the fifth month of pregnancy as a result of the allantois obliteration. Urachal cysts occur as a result of a defect in the obliteration of the duct, anomaly detected mainly in children and very rarely in adults. We present three cases of urachal cysts in adults, one of them detected during the study of abdominal pain and the other two, found incidentally during the study of other pathologies. In any case the possibility of urachal cysts was clinically suspected. Histologically, these lesions are lined by epithelium of urothelial type with expression of CK7, CK20, CK5/6, P63 and GATA3. The diagnosis of urachal cysts certainty lies in the histopathological study where the morphology, immunohistochemistry and a proper clinical-pathological correlation, allow to differentiate it from other more frequent abdominal cystic lesions in adults.