Iron-binding proteins in adenoid cystic carcinoma of salivary glands: an immunohistochemical study.

An immunoperoxidase staining technique was used for detecting three major iron-binding proteins (transferrin, ferritin and lactoferrin) in 54 adenoid cystic carcinomas (ACCs) of major and minor salivary glands. Twenty-three normal salivary glands were investigated for comparison. Transferrin staining was detected mainly in the intercalated duct and serous acinar cells, and was found inconsistently in the myoepithelial cells surrounding normal ductules. Ferritin was always absent in the normal epithelial component of salivary gland. The presence of lactoferrin was demonstrated in the serous acinar cells and intercalated duct cells of normal salivary tissues. Five histological patterns were found in ACC, and for the cellular components of each, it was possible to establish a special immunohistochemical profile. Transferrin positivity was detected in the small angular cells of 25 cases (48%), in the duct luminal cells of 19 cases (37%) and in the hyalinized stroma of 4 cases (8%). Ferritin staining was positive in the small angular cells of 23 cases (44%) and in the duct luminal cells of 15 cases (29%). Lactoferrin was detected in only duct luminal cells of 38 ACCs (73%). The comparative immunohistochemical analysis between transferrin and ferritin showed a similar distribution in this carcinoma. On the basis of the immunohistochemical data, lactoferrin might be used as a marker of glandular differentiation.