title: Transitional cell carcinoma of the renal pelvis with choriocarcinomatous differentiation. Immunohistochemical and immunoelectron microscopic assessment of human chorionic gonadotropin production by transitional cell carcinoma of the urinary bladder.
abstract: BACKGROUND
  There have been 12 documented cases of choriocarcinoma arising in the urinary bladder, either alone or in combination with other epithelial tumors. It has been shown that some high-grade transitional cell carcinomas (TCC), without obvious syncytiotrophoblastic elements, can produce human chorionic gonadotrophins (HCG).
  
  
  METHODS
  A case of choriocarcinoma, in association with high-grade TCC of the renal pelvis, was encountered in an 80-year-old man. For additional evaluation of HCG production by TCC, 25 consecutive cases of invasive high-grade TCC of the bladder were stained with an anti-HCG antibody. Immunogold staining also was performed in two of the cases studied.
  
  
  RESULTS
  Immunoperoxidase staining of the renal pelvis tumor showed focal positivity for HCG within the TCC and a more intense reaction as the tumor cells differentiated into choriocarcinoma elements. Seven of the 25 cases (28%) displayed varying degrees of reactivity within individual cells or groups of cells. In an additional case, typical syncytiotrophoblastic giant cells without cytotrophoblasts were seen in a high-grade TCC. Immunogold studies demonstrated positive labeling in the cytoplasm of carcinoma cells in a case of TCC without syncytiotrophoblasts and in the syncytiotrophoblastic giant cells in the one case in which these were present.
  
  
  CONCLUSIONS
  The findings support a metaplastic origin of cases of choriocarcinoma arising primarily in the urothelial tract.
authors.affiliation: Department of Pathology, Victoria Hospital, London, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Grammatico
authors.forename: D J
authors.initials: DJ
authors.lastname: Grignon
authors.forename: P
authors.initials: P
authors.lastname: Eberwein
authors.forename: R R
authors.initials: RR
authors.lastname: Shepherd
authors.forename: S A
authors.initials: SA
authors.lastname: Hearn
authors.forename: J C
authors.initials: JC
authors.lastname: Walton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000276:immunology / Q000648:ultrastructure*; D002471:Cell Transformation, Neoplastic; D002822:Choriocarcinoma / Q000276:immunology* / Q000648:ultrastructure*; D006063:Chorionic Gonadotropin / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000276:immunology / Q000648:ultrastructure*; D007682:Kidney Pelvis / Q000648:ultrastructure*; D008297:Male; D016253:Microscopy, Immunoelectron; D001749:Urinary Bladder Neoplasms / Q000276:immunology* / Q000648:ultrastructure*
chemical_list: D006063:Chorionic Gonadotropin