p16-Positive small cell neuroendocrine carcinoma of the endometrium

Abstract

We report herein a small cell neuroendocrine carcinoma of the endometrium that extended to the cervix and showed strong immunohistochemical staining for p16. The p16 staining raised the possibility of a human papillomavirus (HPV)-related tumor, because in the cervix, a positive p16 immunohistochemical stain is presumptive evidence of HPV. However, the current case was HPV negative. We discuss the molecular pathogenesis of non-HPV-related increased p16 expression.