[Congenital mesoblastic nephroma in an adult: immunohistochemical study]

A case of congenital mesoblastic nephroma in a 60-year-old female patient is described. The clinical onset was gross hematuria of 48 hours evolution and pain in the right renal fossa which irradiated to the iliac fossa of the same side. A routine pathological analysis was carried out on the surgical specimen including an extensive immunohistochemical analysis which was highly positive for keratin in the epithelial lining of the tubular and cystic structures and for desmine and vimentin in the fusocellular stroma of the tumor. The different histogenetic hypotheses are discussed. The importance of a precise anatomopathological diagnosis in order to institute adequate treatment is underscored.