Cell kinetics of pleomorphic adenomas of the parotid gland

The aim of the present study is to characterise the cell kinetics of pleomorphic adenoma of the parotid gland by assessing DNA content and proliferating cell nuclear antigen (PCNA) positivity. In 22 parotid adenomas, DNA content was measured by densitometry in histological serial sections stained with Feulgen's method and PCNA positivity was determined by immunohistochemistry with the monoclonal antibody PC10. To assess the proliferative activity, DNA index and PCNA index were evaluated. It was possible to distinguish two types of adenoma. In Group I there was a prevalence of diploid cells with a low PCNA index. Group II is represented by adenomas with a large percentage of triploid cells and a PCNA index significantly higher than that of Group I. Our findings suggest that the possibility of recurrence or malignant transformation depends on intrinsic biological properties of each adenoma.