Iron binding proteins in gallbladder carcinomas. An immunocytochemical investigation

By immunohistochemistry, the presence of major iron-binding proteins (lactoferrin, transferrin, ferritin) has been investigated in adenocarcinomas (27 cases), adenosquamous carcinoma (1 case), undifferentiated sarcomatoid carcinoma (1 case) and mucinous adenocarcinomas (3 cases) of the gallbladder 10 samples of chronic lithyasic cholecystitis, 4 adenomyomas and 6 tubulo-villous adenomas have also been studied. In a variable share of adenocarcinomas, a positive immunoreactivity for iron-binding antisera was encountered in the cytoplasm, while tubulo-villous adenomas, adenomyomas and the normal epithelium of the gallbladder were generally unreactive. In carcinomatous lesions, the staining intensity was variable between different cases or individual tumour cells. The production of these iron-binding proteins in the gallbladder carcinoma in itself could be related to a greater availability of iron for metabolic processes in the neoplastic cell; alternatively, the cytoplasmic localization of these substances in carcinomatous elements may be a consequence of a defective or impaired function of iron-binding receptors with a modified degree of transmembranous iron transfer.