AN IMMUNOHISTOCHEMICAL STUDY OF P53 PROTEIN IN OVARIAN MUCINOUS NEOPLASMS

p53 gene mutations are among the most common genetic lesions in human cancers. While previous studies have established the presence of p53 p rotein in ovarian carcinomas some have not shown the alteration of the p53 gene to be a feature in benign or borderline ovarian epithelial n eoplasms. In this study we examined both benign and borderline maligna nt/malignant mucinous neoplasms for p53 protein accumulation by the me ans of an anti-human p53 protein monoclonal antibody on paraffin secti ons. Our results show that p53 protein accumulation is associated to a similar degree with both malignant mucinous cystadenocarcinomas and m ucinous cystademonas of borderline malignancy. This suggests that p53 mutations may play an important and early role in the malignant transf ormations of one-third or more of mucinous ovarian neoplasms. Furtherm ore, among the mucinous cystadenomas of borderline malignancy where p5 3 staining was present, staining could be found in the morphologically benign areas thus indicating that, despite their innocuous appearance , such epithelial cells might have already taken a very important step in their evolution to frank malignancy.