Immunohistochemical detection of alpha 1-antitrypsin, alpha 1-antichymotrypsin, transferrin and ferritin in ameloblastoma.
An immunohistochemical study was performed to investigate the presence of alpha-1-antitrypsin (alpha 1-AT), alpha-1-antichymotrypsin (alpha 1-ACT), transferrin and ferritin in 32 ameloblastomas and to evaluate the co-expression of these antibodies. Histologically, we recognized the following 6 patterns in the series of 32 ameloblastomas and at least 2 patterns in variable proportions were present in each of our cases: follicular pattern (21 cases, 66%), plexiform pattern (17 cases, 53%), cystic pattern (21 cases, 66%), acanthomatous pattern (10 cases, 31%), granular cell type (2 cases, 6%), and hyalinized stromal pattern (20 cases, 63%). Neoplastic epithelia of cystic pattern were divided into superficial cell, basal cell and whole layer to compare the immunohistochemical localization. The results made on the various patterns of ameloblastomas were as follows: (1) alpha 1-AT positivity in plexiform, cystic and hyalinized stromal patterns was significantly higher than that of alpha 1-ACT (P < 0.05). (2) The incidence of transferrin in follicular and plexiform patterns was markedly higher than that of ferritin in the same patterns (P < 0.025 and P < 0.01). Transferrin strongly stained metaplastic squamous cells of acanthomatous pattern and basal cells of cystic epithelium. (3) Granular cells reacted with transferrin and ferritin. (4) In follicular and acanthomatous patterns, coexpression of alpha 1-AT and alpha 1-ACT, alpha 1-AT and transferrin, or alpha 1-ACT and transferrin was higher than that of another combination. On the other hand, co-expression of alpha 1-AT and transferrin in plexiform and cystic patterns was higher than that of other antibodies. These results of co-expression of 4 antibodies used in the present study, suggest that the histogenesis of follicular and acanthomatous patterns is different from that of plexiform and cystic patterns.