Fallopian tube high-grade serous carcinoma with intramucosal spread and presenting as a malignancy on pap smear

For the first time, we report a case of a primary high-grade serous carcinoma of the fallopian tube in a 69-yr-old woman with intraepithelial involvement of endocervical glands. The patient had a remote history of tubal ligation and no known personal or family history of breast or gynecologic cancer. She initially presented with an abnormal Pap smear, and, on a subsequent endometrial curettage, detached fragments of high-grade adenocarcinoma were identified. Upon hysterectomy and bilateral salpingoophorectomy, invasive high-grade serous carcinoma was found in the proximal stump of a ligated fallopian tube. Morphologically identical tumor extensively involved the endocervical glands. A single focus of malignant cells was also found at the surface of the lower uterine segment endometrium. By immunohistochemistry, the tumors in the fallopian tube and in the cervix showed the same immunopheonotype. This included diffuse staining for WT-1, PAX-8, p16, and p53, and focal staining for the monoclonal carcinoembryonic antigen. The estrogen receptor was negative. Human papillomavirus-in situ hybridization was also negative. The focus of intramucosal tumor within the endometrium was similarly positive for WT-1 and p53 and negative for the estrogen receptor. The patient was subsequently treated with 6 cycles of carboplatinum and taxol. She remains well with no evidence of recurrent disease. The phenomenon of intramucosal tumor spread to the cervix mimicking primary invasive or in situ cervical adenocarcinoma may present a diagnostic challenge for the pathologist, requiring consideration of an appropriately wide differential diagnosis when interpreting cervical cytology and endocervical and endometrial biopsies.