[Metallothionein expression and its significance in salivary gland tumors]

Expression of metallothionein (MT) in 75 cases of salivary gland tumors was studied by immunohistochemistry. All tumors containing myoepithelial cells were positive for MT immunostaining. In the tumors composed of both adenoepithelial cells and myoepithelial cells, only myoepithelial cells were MT positive. A rather large portion of cells was noted MT positive in myoepithelial carcinoma and myoepithelioma. Compared with S-100 and smooth muscle actin (SMA) antibodies, the effect of staining by MT antibody for myoepithelial cells was more satisfactory. The results indicate that MT may be a better marker for neoplastic myoepithelial cells and useful in the differential diagnosis of salivary gland tumors.