A case of serous endometrial intraepithelial carcinoma with p53 positivity for six years

A 69-year-old postmenopausal woman was referred because she had been taking tamoxifen for four years. Tissues obtained by endometrial curettage were immunopositive for p53, but there was no definite malignancy. At age 73, cytology again showed abnormalities, so we repeated complete endometrial curettage. Again, there was no malignancy, but p53 immunostaining was widely positive. At age 75, hysterectomy was performed because cytological examination showed increasingly abnormal findings and the patient opted for surgery. In the resected uterus, endometrial glands were replaced by malignant cells resembling papillary serous carcinoma cells with high-grade nuclei, but there was no stromal or myometrial invasion. The pathological diagnosis was intraepithelial serous endometrial carcinoma. This is a rare case because we could follow the patient for 6 years by endometrial cytology or endometrial curettage and we observed gradual transformation into endometrial intraepithelial carcinoma.