RESUMEN
Immunohistochemical techniques using monoclonal antibodies were used to investigate the carcinoembryonic antigen (CEA) in gallbladders from 26 patients with gallbladdeer cancer and 26 patients without cacer, including normal mucosa, areas of pyloric metaplasia and areas identified by the presence of "clear cells". All carcinomas were strongly positive for CEA but 61% of noncancerous samples were also positive. However, only 1 of the last samples was strongly positive. According to hystologic type the positivity for CEA in noncancerous samples was 6/11 in normal mucosa, 6/8 in samples with intestinal metaplasia and 1/8 in samples with pyloric metaplasia (p < 0.05). Thus a negative reaction for CEA is 100% specific for absence of cancer. If mild reactions are disregarded, strong reaction for CEA is 81% specific for cancer