Primary pure squamous cell carcinoma of the endometrium: a case report.

Because primary pure squamous cell carcinoma (SCC) of the endometrium is very rare and its frequency is unknown, the author reviewed 142 archival hysterectomy specimens of endometrial cancers. As the results, one case of primary pure SCC was found. Thus, the frequency of SCC of the endometrium was 0.7% of all endometrial malignancies in our institution. The patient was a 72-year-old woman presenting with uterine bleeding. Uterine curettage biopsy and uterine discharge cytology revealed SCC. No malignancy was seen in cervical biopsy. Radical hysterectomy, bilateral salpingo-oophorectomy, omentectomy and lymph node dissection were performed. The endometrial carcinoma was an infiltrative polypoid tumor composed of non-keratinizing SCC with stratification and intercellular bridges. No adenocarcinoma element was recognized. The SCC cells were immunohistochemically positive for p53 protein and showed high Ki-67 antigen (labeling, 70%). The SCC was found to invade into the deeper third of the myometrium. No tumor cells were seen in other sites including the cervix, ovaries, omentum, and lymph nodes. The patients was FIGO stage IC (pT1C, N0, M0), and was treated with radiation and adjuvant chemotherapy. The patient is now alive without recurrence and metastasis 15 months after the operation.