Lymphoepitheliomalike carcinoma: an unusual variant of endometrial cancer. A report of two cases.

Two undifferentiated carcinomas of the endometrium with a prominent inflammatory reaction that were morphologically similar to nasopharyngeal cancers occurred in two patients who had postmenopausal bleeding. Tumor cells in both patients were large with indistinct cytoplasmic borders, vesicular nuclei, and prominent nucleoli, were arranged in sheets, in groups, or singly, and surrounded by an intense inflammatory component of lymphocytes, plasma cells, and karyorrhectic debris. Tumor cells were keratin (AE1/EA3) and epithelial membrane antigen (EMA) positive and leukocyte common antigen (LCA) negative. All three methods used for the detection of Epstein Barr virus (EBV) infection were negative. The first patient (International Federation of Gynecology and Obstetrics [FIGO] stage IVB) received chemotherapy and is alive and free of disease 9 months after diagnosis. The second patient (FIGO stage IIIC) received radiation therapy and chemotherapy 6 months after evidence of extensive retroperitoneal disease and died of disease 1 year after diagnosis. Tumors with these histologic features have been designated as lymphoepitheliomalike carcinomas (LELC) when they occur outside the nasopharynx. LELC can occur in the endometrium and, in this location, may not be associated with EBV infection.