[Chorionic gonadotrophic hormone and transitional cell carcinoma of the bladder. Immunohistochemical characterization of HCG and its alpha and beta subunits].

Investigation of cellular localization of hCG and alpha- and beta- subunits in 17 transitional cell carcinomas of urinary bladder was performed using immunohistochemical techniques. Serial sections were tested with monoclonal antibodies to hCG, free beta hCG and free alpha hCG. Transitional cell carcinomas producing hCG and/or beta hCG are easily found (6/17 cases). None of these tumors correspond morphologically to a choriocarcinoma. However, it must be mentioned that neoplastic areas exhibit some features reminiscent of a choriocarcinomatous structure. Notably, positive cells can be disposed at the periphery of neoplastic nests, mimicking the arrangement of syncytiotrophoblast. Positive neoplastic cells express hCG and/or beta hCG; alpha hCG immuno-reactivity is quite rare. The relative distribution of hCG/beta hCG is excessively variable from case to case. In contrast, normal transitional epithelium contains endocrine cells which only express the alpha-subunit of hCG.