Pleomorphic adenoma of the salivary glands: prospective clinicopathologic and flow cytometric study.

Abstract

Primary surgery is the appropriate treatment for most pleomorphic adenomas of the salivary glands. However, no reliable criteria have been established to predict tumors with aggressive features. In 44 patients treated for salivary pleomorphic adenoma, clinicopathologic features and flow cytometric findings were recorded. S-phase fractions were classified as low (0%-1%), intermediate (1.1%-5%), and high (>5%). The relationship between clinicopathologic parameters and flow cytometric DNA analysis was assessed with the Pearson's correlation coefficient. The mean tumor size was 24.4 mm. Microscopically, myxoid structures predominated in 61.4% of cases. Only five specimens showed high S-phase fractions. All samples were DNA diploid (mean coefficient of variation 3.2%). S-phase fraction and tumor size correlated significantly (r = 0.73, P = 0.003). Two patients with recurrent tumors had high S-phase fractions both on the first resected specimens and at the time of the second operation. The S-phase fraction may be a valuable predictor of aggressive behavior in salivary pleomorphic adenomas. High S-phase fractions were associated with higher tumor size and a greater tendency to recur.