RESUMEN
Endometrial cancer is the most common gynecologic malignancy that has often proceeded by a premalignant phase. Modern molecular and immunostaining methods for precancerous lesions diagnosis have been expanded. One of the genetic alternations in the endometrial cancer carcinogenesis is the mutational activation of the K-ras oncogene. K-ras mutation has recognized to occur at an early stage of neoplastic progression in the endometrium. The purpose of this study is to investigate the expression pattern of K-ras gene in atypical and nonatypical hyperplastic endometrium. In a prospective study in the referral gynecologic hospital in Tehran, immunohistochemical evaluation of K-ras has performed on 72 consecutive specimens in two following groups: endometrial hyperplasia without atypia [n: 36], and endometrial hyperplasia with atypia [n: 36]. Staining of cells has evaluated in arbitrary quantitative methods in regards to both slides area staining and intensity of color reaction. K-ras immunoreactivity has seen in 3/36 [8.3%] cases of non atypical hyperplasia and in 2/36 [5.6%] cases of atypical hyperplasia [P: 0.64]. We have not establish any significant differences in K-ras expression between the atypical and nonatypical hyperplastic endometrium, and our data has supported this view that K-ras mutation is a very rare event in human endometrial carcinogenesis