Malignant Transformation Rate and P53, and P16 Expression in Teratomatous Skin of Ovarian Mature Cystic Teratoma

Objective: To investigate the incidence of malignant transformation and P53 and P16 expression interatomatous skin of ovarian mature cystic teratoma. Materials and
Methods: Data on ovarian teratomaspecimens in nearly 10 years were reviewed. P53 and P16 expression were detected by immunohistochemistryin 25 cases of teratomatous skin of ovarian mature cystic teratoma, 20 cases of squamous cell carcinoma and 2cases of squamous cell carcinoma originated from teratomatous skin.
Results: Of 1913 cases of ovarian maturecystic teratoma in nearly 10 years, only two cases of squamous cell carcinoma were found in teratomatous skin,with malignant transformation rate of 0.1045%. P53 expression was detected in 2 cases squamous cell carcinomaoriginated from teratomatous skin and P16 overexpression in one. There were no expressions of P53 and P16 in25 cases of teratomatous skin of ovarian mature cystic teratoma. Of 20 cases of squamous cell carcinoma P53overexpression (positive rate of 55%) was detected in 11 cases, P16 overexpression (positive rate of 35%) in 7cases. The positive rates of P53 and P16 expression in squamous cell carcinomas were significantly higher thanthat in the teratomatous skins (p< 0.001, p= 0.002).
Conclusions: There was low risk of malignant transformationin teratomatous skin of ovarian mature cystic teratoma which can be explained by lower P53 and P16 expressioninteratomas than that in squamous cell carcinoma.