Borderline Ovarian Tumor Recurrence after Two Decades: The Importance of Long-term Surveillance

Dear Editor, Here, we report a rare case of recurrent serous borderline ovarian tumor (BOT) occurring 20 years after initial diagnosis, surgery, and chemotherapy. BOTs (also known as atypical proliferative tumor) are characterized by growth patterns and cytological features intermediate between benign and malignant ovarian tumors, without stromal invasion. They constitute 14%–15% of all primary ovarian neoplasms and are staged using the International Federation of Gynecology and Obstetrics system for ovarian cancer.[1] The majority of BOTs are serous or mucinous, with rare subtypes such as endometrioid, clear cell, or Brenner borderline tumors.[2] Most patients are diagnosed at an early stage, with an average onset 10 years younger than ovarian cancer. Recurrence rates range from 5% to 20%.[3] A 46-year-old female, gravida 1 para 1, with a history of stage IIIC serous BOT diagnosed over 20 years ago, presented with bilateral flank pain, lower leg edema, and gross hematuria for 3 months. She had undergone optimal debulking surgery, including hysterectomy, bilateral salpingo-oophorectomy, and omentectomy, followed by chemotherapy with cisplatin and cyclophosphamide. The patient achieved complete remission but developed pelvic cysts 3 years prior to admission. Pathological findings from cyst aspirations and resections were benign. Her medical history included surgical menopause in her 20s and long-term smoking and alcohol use. Clinical evaluations revealed bilateral pelvic cystic tumors measuring 9.5 cm and 10.5 cm [computed tomography, Figure 1], hydronephrosis, and elevated tumor markers (CA125: 139.1 U/mL and carcinoembryonic antigen (CEA): 3.7 ng/mL). She underwent ureteral stent placement and laparoscopic pelvic cystic tumor resection. Histopathology confirmed serous BOT on the left pelvis and a hemorrhagic cyst on the right pelvis [Figure 2]. Immunohistology showed diffuse positivity for PAX8 and WT-1, focal positivity for p53, and high estrogen receptor expression.Figure 1: Computed tomography of the abdominal region. Two cystic tumors in the pelvis favor retained ovary-related cystic tumors of approximately 9.5 cm on the right side and 10.5 cm on the left side (arrow)Figure 2: Laparoscopic view of surgery. (a) Ovarian cyst in the pelvic cavity. (b) Inside view of the cyst. (c) A drainage tube was placed after the resection of the ovarian cystResidual disease (<1 cm) on the intestinal surface could not be completely resected. Chemotherapy was initiated with paclitaxel and carboplatin, and the patient was discharged without complications. The final diagnosis was recurrent serous BOT with residual disease, requiring continued follow-up and chemotherapy. This case highlights the potential for late recurrence of BOTs even after extended remission. The median age at diagnosis for BOTs is 55.2 years. BOT is indolent and slow-growing. Serous histology accounts for 65%–70% of BOT cases, with micropapillary features increasing recurrence risks.[2] Prognosis is generally favorable, but BOTs can impact quality of life, reproductive function, and endocrine maintenance.[4] Factors associated with recurrence include advanced stage, micropapillary components, and fertility-sparing surgery.[5] Recurrence rates are higher with minimally invasive surgery compared to laparotomy and with ovarian cystectomy compared to oophorectomy.[6] Reports show varied outcomes in BOT recurrence, from long-term survival to aggressive progression. Management typically involves surgery, with conservative or radical approaches tailored to patient fertility desires and disease extent.[7,8] Platinum-based chemotherapy (carboplatin plus paclitaxel) can provide clinical benefit in advanced borderline ovarian cancer.[9] Long-term surveillance is critical, especially for fertility-sparing treatments, as recurrence can occur decades later.[10] This case underscores the importance of vigilant long-term follow-up in BOT patients, as recurrence can occur even after prolonged remission. Individualized treatment strategies and regular monitoring are essential for optimizing outcomes and early detection of recurrence. Ethics statement This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and its amendments. The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Author contributions D.D. contributed to conceptualization, methodology, formal analysis, writing-original draft preparation, and writing, review, and editing. W.L, P.L contributed to data curation and wrote the original draft. All authors have read and agreed to the final version of the manuscript. Data availability statement All data generated or analyzed during this study are included in this published article. Financial support and sponsorship Nil. Conflicts of interest Dr. Dah-Ching Ding, , an editorial board member at Gynecology and Minimally Invasive Therapy, had no role in the peer review process of or decision to publish this article. All authors declared no conflicts of interest in writing this paper.