The relationship between nuclear DNA content in salivary gland tumors and prognosis. Comparison of mucoepidermoid tumors and acinic cell tumors.

Differences in prognosis between salivary gland mucoepidermoid tumors and acinic cell tumors were compared by means of conventional histopathological grading and nuclear DNA content which was assessed cytochemically by a scanning cytophotometric procedure. The mucoepidermoid tumors were found to show a stronger correlation between histopathological grading and prognosis than did the acinic cell tumors. By using DNA quantification, valuable additional information could be obtained for predicting the behavior of the mucoepidermoid tumors, whereas there was no correlation between DNA content and prognosis for the acinic cell tumors. Regarding the relatively "benign" clinical course of most mucoepidermoid tumors, the term "tumor"--as proposed by the World Health Organization's classification--seems appropriate. In contrast, the more severe clinical courses of the acinic cell tumors justify the use of the term "carcinoma" instead.