Tumors of the major and minor salivary glands: review of 25 years of experience

Abstract

Reports from various countries, but never from Israel, have presented demographic data and the relative frequency of various salivary gland tumors. We reviewed 25 years of experience with-245 patients treated for salivary gland tumors, arising in the parotid [142 patients [pts], 57.9%], submandibular [34 pts, 13.9%], sublingual [2 pts, 0.8%] and minor salivary glands [67 pts, 27.3%]. Of these, 73.5% were classified as benign and 26.5% were classified as malignant. The tumors were analyzed according to sex and age of the pts, histopathological type and site. There was a female preponderance [1.16:1.0] for the benign tumors and a male preponderance [1.32:1.0] for the malignant tumors. The mean age for pts with malignant tumors was 12.6 years more than for pts with benign tumors [55.2 +/- 2.2 and 42.6 +/- 2.6 years, respectively]. The principal site for benign tumors was the parotid gland [67.8%], followed by the minor salivary glands [18.9%] and the submandibular gland [13.3%]. We did not observe any benign tumors in the sublingual glands. The principal site for malignant tumors was the minor salivary glands [50.8%], followed by the parotid gland [30.8%], the submandibular gland [15.4%] and the sublingual gland [3.0%]. We present the proportional distribution of both benign and malignant tumors; pleomorphic adenoma was the most common benign tumor of epithelial origin [76.1%] while the most commonly encountered malignant tumor was adenocarcinoma [including the acinic-cell and low-grade polymorphous subtypes] [27.7%]. The most striking result of this study is the demonstration of a recent increase in the incidence of salivary malignant tumors, possibly as a result of greater exposure to ultraviolet radiation. It is highly probable that the increase in malignant tumors will continue during the coming years in countries with intense solar radiation over long periods of time.