Endometrioid Endometrial Carcinoma With Spindle Cells–Aberrant p16 and p53 Expression

Endometrioid carcinoma is known for its diverse morphology and may pose a diagnostic dilemma when it presents with a spindle cell component. We present a case of a 65-year-old woman with postmenopausal bleeding. Physical examination showed a mass protruding from the external cervical os. The patient underwent biopsy followed by hysterectomy. Pathologic examination showed an endometrioid endometrial carcinoma with spindle cell differentiation arising in an endometrial polyp, which raised a variety of differential diagnoses. Prior reports of this tumor type showed nonaberrant immunohistochemical expression of p16 and p53. However, this case showed p16 and p53 overexpression indicating that there is a spectrum of these tumors.