Metastatic Urothelial Carcinomas with high serum level of CA19-9. apropos of three cases

CA 19-9 immunoexpression in cytological material, as shown by few case reports in   the literature, may have a diagnostic significance in urothelial carcinoma, especially in cases of metastatic disease with unknown primary.  In the present paper, we present three cases of metastatic urothelial carcinoma with elevated CA 19-9 serum levels. The lesions were located in the lung, ascitic fluid and the skin of the right inguinal region. Paracentesis was done and ThinPrep smears were prepared for cytological diagnostic purposes. For immunocytochemical investigation, antibodies against cytokeratins 7 and 20 and GATA binding protein 3 (GATA-3) were included as well as the monoclonal antibody against CA19-9. Morphological and immunocytochemical examination (positivity for CK7, GATA-3 and/or CK20), revealed the urothelial origin in these three cases. ABC-peroxidase staining also showed the presence of  CA 19-9 in some tumor cells. Metastatic urothelial carcinoma may express CA19-9, as detected immunocytochemically in our cases, and may also cause elevation of CA19-9 serum levels.