Immunoperoxidase study on adenomatoid tumor of the epididymis using anti-mesothelial cell serum.

The mesothelial origin of epididymal adenomatoid tumor is supported by the current study for the presence of mesothelial antigen in the tumor cells. By an indirect immunoperoxidase technique, anti-mesothelial cell serum showed positive cytoplasmic staining in five of the six adenomatoid tumors studied. Previous findings of the presence of strong cytoplasmic keratin and the absence of carcinoembryonic antigen and Factor VIII-related antigen in these tumor cells are also confirmed by this study.