Oncocytic tumors of salivary gland type: a study with emphasis on nuclear DNA ploidy

We studied nine cases of oncocytic tumors of salivary gland type in order to evaluate their clinico-pathologic profiles and nuclear DNA patterns as criteria for the differential diagnosis between benign and malignant forms. The tumors were located at the parotid gland, palate, and orbit. The age of the patients ranged between 35 and 85 years and the sex ratio (F:M) was 1:0.8. Seven tumors were capsulated and had typical cytology: they were composed of polyhedrical cells with large, eosinophilic, and granular cytoplasm and dark nucleus. The remaining two tumors exhibited malignancy criteria for the oncocytic tumors: atypia, pleomorphism, and mitosis. The evaluation of the nuclear DNA content was also distinct: benign tumors had a DNA diploid pattern and the malignant neoplasms displayed a DNA aneuploid pattern. These observations point to DNA nuclear assessment as an additional criterion to discriminate neoplasms with divergent clinical behavior and prognosis.