Adenomatoid tumors. Immunohistochemical study and histogenesis.

Four testicular adenomatoid tumors were studied by immunohistochemistry, using the following antibodies to cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and factor VIII-related antigen. Cytokeratin and epithelial membrane antigen demonstrated a different pattern of positive immunostaining while carcinoembryonic antigen and factor VIII-related antigen proved constantly negative. Our findings support a mesothelial origin for adenomatoid tumors.