In order to develop a more objective method of evaluating the origin of
adenolymphoma, we immunohistochemically investigated the expression of cytokeratins,
vimentin,
S-100 protein, and alpha-smooth-muscle actin using the
avidin-
biotin-
peroxidase (ABC) method in
ethanol-fixed
paraffin-embedded specimens from 8
adenolymphomas. Several kinds of
monoclonal antibodies which react monospecifically with each subclass of cytokeratins were used. Results were compared with specimens of 8 normal parotid glands by
radical neck dissection in patients with other diseases who had not undergone
radiotherapy. In the
adenolymphoma specimens, basal cells were strongly positive for CK-6, but reactivity of columnar cells was apparently reduced. In contrast, columnar cells were strongly positive for CK-7, but reactivity of basal cells was reduced. In normal parotid gland specimens, CK-7 was also detected in all columnar cells in the ductal system, although some duct cells around the columnar cells, which showed strong CK-6 expression, showed poor CK-7 expression. alpha-smooth-muscle actin was present in myoepithelial cells in normal parotid gland specimens, but not in basal cells of
adenolymphoma or of the normal ductal system, which were CK-6-positive. As these characteristic findings were consistently observed in all specimens, the demonstration of CK-6, CK-7, and alpha-smooth-muscle actin may be useful in the recognition and classification of columnar and basal cells. CK-8 was present in both columnar and basal cells of
adenolymphoma and of the normal duct, but in the normal parotid gland, acinus cells were also strongly positive for CK-8.(ABSTRACT TRUNCATED AT 250 WORDS)