Apoptosis and P53 in inverting papilloma of the sinonasal tract

The objective of this study was to identify apoptotic bodies and p53 positi vity in inverting papilloma lesions to study these two as biomarkers in pre malignant lesions. Archival specimens of 15 patients with inverting papillo ma between the years 1992 and 1995 were retrieved. In situ end labeling tec hnique was used to identify apoptotic bodies. Immunohistochemistry was used to detect p53 in the same specimens. The clinical course was evaluated con ducting a retrospective chart review in these patients. Compared to normal epithelium, inverting papilloma lesions had a greater proportion of apoptot ic bodies, which was nearly statistically significant (average 0.506/100 ce lls for inverting papilloma compared with 0.1/100 cells for the normal surr ounding, tissue). Four cases of inverting papilloma were p53 positive. Ther e was, however, no association between p53 positive staining and the apopto tic rate. The minimum follow-up for patients was 2 years. All had a uniform ly good clinical outcome with only one patient who was p53 positive showing concurrent squamous cell carcinoma. We concluded that inverting papilloma contained a higher average number of apoptotic bodies compared with normal surrounding sinonasal tissue. This showed a trend toward a positive between the apoptotic rate and premalignancy, suggesting both increased cellular p roliferation and increased cell death may occur in such lesions. In this st udy p53 did not show a positive association with the apoptotic rate, sugges ting that p53 may not be directly involved in the apoptotic regulatory path way in inverting papillomas.