[A case of urothelial carcinoma with trophoblastic differentiation and review of the literature].

We report the case of a 43-year-old woman, who was admitted for intense pelvic pains. Biological investigations showed an increase of β-HCG level. The abdomino-pelvic computed tomography revealed a voluminous mass infiltrating the bladder. A transurethral resection was performed. The histopathological examination evidenced an invasion of the bladder by a massive carcinomatous proliferation composed of clear epithelial cells with in some places syncytiotrophoblastic cells and rarely cytotrophoblastic cells. Immunohistochemical analyses revealed a staining of GATA-3 by the two components, an expression of p63 by the clear cell urothelial component and the immunoreactivity of β-HCG by the trophoblastic component. Ki-67 labeling index was very high. The diagnosis of mixt urothelial carcinoma with clear cells and trophoblastic differentiation was proposed. This is a rare difficult histopathological diagnosis which should be known by pathologists. It is correlated to a poor clinical outcome with a high tendency to lymph node or visceral metastases.