Minimal uterine serous carcinoma: a clinicopathological study of 40 cases.

The term 'minimal uterine serous carcinoma' has been proposed to include serous carcinomas with invasion limited to the endometrium (superficial serous carcinoma), and those without stromal invasion (intraepithelial serous carcinoma or endometrial intraepithelial carcinoma). Both lesions display similar cytological and immunohistochemical profiles of a typical invasive serous carcinoma with a high nuclear grade and an overexpression of mutant p53 protein. We studied the clinicopathologic features of 40 cases of minimal uterine serous carcinoma. All patients were postmenopausal and underwent hysterectomy and surgical staging procedures. There were nine cases of intraepithelial serous carcinoma and 31 cases of superficial serous carcinoma. Five intraepithelial serous carcinomas and 16 superficial serous carcinomas exclusively involved an endometrial polyp. A total of 18 minimal uterine serous carcinomas also involved, in addition to a polyp, the endometrium proper in the form of intraepithelial serous carcinoma (13 cases) and superficial serous carcinoma (five cases). Overall, minimal uterine serous carcinomas were found to involve an endometrial polyp in 88% of the cases (35/40) and were confined to the polyp in 53% (21/40). Extrauterine tumors were present in 45% of the cases (18/40). In all, 22 patients with tumor limited to their uteri demonstrated an overall survival of 94% (2-73 months of follow-up). Eight of 18 patients with extrauterine tumors died of their malignancy (1.5-62 months of follow-up). In conclusion, a significant majority of minimal uterine serous carcinomas involve an endometrial polyp. Complete surgical staging is important to predict the prognosis. When the lesion is confined to an endometrial polyp and/or the endometrium proper, the clinical outcome is excellent.