Primary serous borderline tumor arising from the vaginal stump

A 72-year-old, 3 gravida 3 para, postmenopausal woman with a history of abdominal simple total hysterectomy with bilateral salpingo-oophorectomy for uterine leiomyoma and ovarian endometriosis in her 40 s, visited our hospital for purulent genital discharge. Specular examination revealed a white tumor with a necrotic tip in the vaginal cavity ( Fig. 1 ). She had no relevant medical history except for a uterine myoma and no relevant family history. Fig. 1 Finding of a vaginal tumor by speculum examination. Finding of a vaginal tumor by speculum examination. Cytopathological examination of the tumor surface revealed necrotic cells without atypical cells, and a punch biopsy of the tip of the tumor revealed a benign serous tumor. Preoperative CA125, CA19-9, and carcinoembryonic antigen levels were within their respective normal limits. Pelvic magnetic resonance imaging revealed a 50 mm diameter vaginal tumor with high intensity on both T2-weighted images ( Fig. 2 A) and diffusion-weighted images, but a decrease in the apparent diffusion coefficient signal was not observed. Furthermore, preoperative computed tomography spanning the cervix and pelvic cavity demonstrated no abnormal findings. Fig. 2 (A): T2-weighted magnetic resonance image. A well-defined T2-high-intensity vaginal tumor was confirmed. (B): Macroscopic finding of the surgically resected tumor. A white partial necrotic tumor was present at the vaginal stump. (A): T2-weighted magnetic resonance image. A well-defined T2-high-intensity vaginal tumor was confirmed. (B): Macroscopic finding of the surgically resected tumor. A white partial necrotic tumor was present at the vaginal stump. We performed a vaginal resection of the tumor to establish a definitive pathological diagnosis and alleviate the patient’s symptoms. The tumor originated from the vaginal stump, and no metastatic lesions were observed in the vaginal wall. An index finger-sized club-shaped solid tumor ( Fig. 2 B) was easily resected vaginally, and vaginal stump cauterization was performed. Although the patient did not receive postoperative adjuvant therapy, no signs of recurrence were observed 15 months after surgery, with examination intervals of three months.

Yukiko Matsuzawa: Writing – original draft, Data curation. Mitsumasa Osakabe: Writing – review & editing, Supervision, Methodology, Data curation. Kazuhiro Murakami: Writing – review & editing, Supervision, Methodology, Data curation. Yoh Watanabe: Writing – review & editing, Validation, Supervision, Methodology, Investigation, Data curation.

Written informed consent was obtained from the patient for publication of this case report and accompanying images.

Neither serous histology nor borderline tumors have been previously reported as borderline primary vaginal tumors. However, from the characteristics of the present patient (tumor cells with cilia, papillary growth, strong positivity for WT-1, and normal expression of P53 and DNA mismatch repair-related proteins), we diagnosed her with a serous borderline tumor. Previously, Quan et al. reviewed 56 cases of primary vaginal cancer in women with previous hysterectomy for benign diseases and reported the following clinicopathologic characteristics: patient ages from 33 to 86 years; vaginal cancer occurred between five and 25 years after hysterectomy; the most frequent histological subtype was squamous cell carcinoma, while adenocarcinoma remained in 39 %; and the majority of known adenocarcinoma histological subtypes were endometrioid carcinomas. Furthermore, Bruno et al. studied 170 cases of vaginal intraepithelial neoplasia (VaIN) in post-hysterectomized women and reported that the occurrence of VaIN strongly correlated with persistent high-risk human papillomavirus (HPV) infections, especially type 16 infection. Furthermore, Staats et al. studied 18 cases of primary endometrioid carcinoma in hysterectomized women and reported that the occurrence of vaginal endometrioid carcinoma closely correlated with vaginal endometriosis. Regarding the endometriosis as a histogenesis of adenocarcinomas, Mortlock et al. studied the genetic relationship between endometriosis and ovarian cancer histology and found that not only clear cell carcinoma and endometrioid carcinoma, but also high-grade serous carcinoma correlated with endometriosis. Moreover, Cozzolino et al. reviewed a total of 23 eligible studies regarding vaginal cancer and endometriosis and reported that vaginal cancer arising from endometriosis is extremely rare and endometrioid adenocarcinoma is the most common histological subtype followed by endometrial stromal sarcoma. Based on the results of previous studies, the cause of vaginal carcinoma in hysterectomized women is thought to be high-risk HPV infection, for squamous carcinoma and endometriosis for adenocarcinoma. We checked the surgical record of her hysterectomy from 32 years prior and confirmed that bilateral ovaries and fallopian tubes had been completely removed. Moreover, we confirmed adhesion of slightly enlarged bilateral ovaries to the Douglas pouch due to endometriosis. Additionally, the pathological report revealed bilateral ovarian endometriosis and uterine leiomyoma; however, there were no abnormal findings in the uterine cervix. Although vaginal endometriosis was not confirmed at present surgery, the present tumor may have occurred because of old, undiagnosed vaginal endometriosis. Generally, a partial or total vaginectomy and detailed assessment are required in cases of primary vaginal carcinoma. Nonetheless, highly invasive surgery was avoided following a prior accurate pathological diagnosis by tumor resection. Gynecologic oncologists should be aware that serous borderline tumors can occur at the vaginal stump in hysterectomized women and select treatments accordingly.

Although 161 patients with primary vaginal carcinoma are reported annually in Japan, the most frequent histological diagnosis is squamous carcinoma, and adenocarcinoma accounts for 4.3 % of all cases ( Patients annual report for 2021 in Japan ). Furthermore, several patients with clear cell carcinoma ( Watanabe et al., 2002 ), endometrioid carcinoma ( Staats et al., 2007 ), and gastric-type adenocarcinoma ( Wong et al., 2018 ) have been reported; however, no cases of serous carcinoma, including borderline tumors, have been reported in the English literature. Here, we report the clinicopathological characteristics of a primary serous borderline tumor of the vagina arising from a vaginal stump.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Histopathological examination of the surgically resected tumor revealed columnar tumor cells with papillary formation and mildly overlapping arrangement; however, no stromal invasion was observed ( Fig. 3 A). The tumor cells showed moderate atypia with prominent nucleoli and cilia ( Fig. 3 B). Fig. 3 Findings of the Hematoxylin-Eosin-stained specimen (A) Tumor cells developed with papillary formation, and no stromal invasion was observed. (B). Tumor cells showed mild atypia and cilium. Findings of the immunohistochemical stained specimen. (C) Strong positive for WT-1. (D) Weak-to-moderate positivity for P53. Findings of the Hematoxylin-Eosin-stained specimen (A) Tumor cells developed with papillary formation, and no stromal invasion was observed. (B). Tumor cells showed mild atypia and cilium. Findings of the immunohistochemical stained specimen. (C) Strong positive for WT-1. (D) Weak-to-moderate positivity for P53.

Immunohistochemical staining revealed a strong positivity for WT-1 ( Fig. 3 C), weak-to-moderate positivity for P53 ( Fig. 3 D), and normal expression of MLH1, PMS2, MSH2, and MSH6. Based on the histopathological and immunohistochemical findings, the patient was diagnosed with a primary serous borderline tumor of the vagina, T1NXM0.