1996 Volume 42 Issue 8 Pages 843-845
Metallothionein (MT), a low molecular weight metal binding protein, has been implicated in the proliferative activity of carcinoma cells. In this report, tissue sections from six cases of mucoepidermoid carcinoma of the oral mucosa were studied immunohistochemically to characterize the expression of MT and to evaluate implications for tumor histological differentiation. The mean percentage of MT positive cells in the mucoepidermoid carcinomas (3.1%, n=6) was significantly lower than those in normal oral mucosa (38.0%, n=10) and oral squamous cell carcinomas (56.0%, n=7). When analyzed according to cell type of the mucoepidermoid carcinomas, 1.1% of the mucous cells, 4.7% of the epidermoid cells, and 1.7% of the intermediate cells were positive for MT immunoreactivity. The incidence of MT expression was significantly lower than that of the normal oral mucosa and the oral squamous cell carcinomas (p<0.001).