The Differences between Benign Mixed Tumor and Papillary Cystadenoma Lymphomatosum in Proliferative, Apoptotic and Antiapoptotic Activities

Abstract

Background:The majority of salivary glands tumors are benign mixed tumors. The present study was aimed to evaluate the differences between benign mixed salivary glands tumor and papillary cystadenoma lymphomatosum regarding the tumor cell proliferation rate, apoptotic and antiapoptotic activities. Methods: The study was performed on archived paraffin-embedded salivary glands tissue of 23 benign mixed tumor and five cystadenoma lymphomatosum. Sections were stained with hematoxylin and eosin and cases with definite diagnosis were selected for immunohistochemistry. The immunoreactivity was assessed in areas of highest positivity regarding Ki-67, P53 and bcl-2. Results: Benign mixed tumor and papillary cystadenoma lymphomatosum showed negative immune expression for Ki-67. The P53 immune staining in benign mixed tumor appeared negative while the papillary cystadenoma lymphomatosum appeared with a mild positive staining. The bcl-2 immune expression in benign mixed tumor was moderately positive while the papillary cystadenoma lymphomatosum was mildly positive. Conclusion:The benign mixed tumors showed significantly more Ki-67 and bcl-2 immune labeling indexes than papillary cystadenoma lymphomatosum, but the P53 immune expression was less (P<0.05). This indicated that the P53 expression was not correlated with the Ki-67 or bcl-2 over expression.