Ovarian Clear Cell Carcinoma Presented as Rapidly Progression of Abdominal Mass in a Postmenopausal Woman: A Case Report

Soe Lwin¹, Syed Rahim Syed Hamid¹, Malhi Fatehpal Singh¹, Aruku Naidu¹, Tin Moe Nwe¹, Khin Than Yee¹, Myat San Yi², Swe Swe Latt³

¹Faculty of Medicine, Royal College of Medicine Perak, Universiti Kuala Lumpur, Ipoh, Perak, Malaysia.

²Suri Seri Begawan Hospital, Kuala Belait, Brunei.

³Department of Public Health Medicine, RCSI & UCD Malaysia Campus, RUMC, Penang, Malaysia.

*Corresponding Author E-mail: soelwin@unikl.edu.my

ABSTRACT:

Ovarian clear cell carcinoma (OCCC) is a distinct and relatively uncommon subtype of epithelial ovarian cancer, characterised by unique histopathological features, molecular alterations, and clinical behaviour. It is often associated with endometriosis and demonstrates relative resistance to conventional platinum-based chemotherapy. We report the case of a 60-year-old nulliparous postmenopausal woman who presented with a rapidly enlarging abdominal mass, weight loss, and pressure symptoms over three months. Imaging revealed a large right adnexal solid-cystic mass suggestive of ovarian malignancy with concomitant uterine fibroids. Tumour markers were elevated, particularly CA 125 and CA 19-9. She underwent definitive surgical management, including total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and appendicectomy. Histopathological examination confirmed ovarian clear cell carcinoma, FIGO stage IC. She subsequently commenced adjuvant chemotherapy. This case highlights the aggressive clinical presentation of OCCC in a postmenopausal woman and underscores the importance of early recognition, comprehensive surgical staging, and histopathological diagnosis. OCCC remains a therapeutic challenge due to its chemoresistant nature, necessitating ongoing research into targeted therapies.

KEYWORDS: Ovarian clear cell carcinoma, post menopause, adnexal mass, epithelial ovarian cancer.

INTRODUCTION:

Ovarian cancer remains one of the leading causes of gynaecological cancer-related mortality worldwide. Among epithelial ovarian cancers, ovarian clear cell carcinoma (OCCC) accounts for approximately 5–10% of cases and represents a biologically distinct entity with unique clinical, pathological, and molecular characteristic.^1&3 OCCC is more frequently diagnosed at an early stage compared to high-grade serous carcinoma; however, it is associated with poorer outcomes in advanced stages due to intrinsic resistance to platinum-based chemotherapy.³

Histologically, OCCC is characterised by clear or hobnail cells arranged in solid, tubulocystic, or papillary patterns, often expressing markers such as Napsin A and hepatocyte nuclear factor-1β (HNF-1β).^3&6 Clinically, patients may present with nonspecific symptoms, including abdominal distension, pain, or pressure effects, leading to delayed diagnosis.

We present a case of stage IC ovarian clear cell carcinoma in a postmenopausal nulliparous woman with rapid abdominal mass enlargement and systemic symptoms, highlighting diagnostic challenges and management considerations.

Case Report

A 60-year-old nulliparous woman presented with progressive abdominal distension and a palpable right iliac fossa mass for three months. The swelling was gradually increasing in size, globular in shape, hard in consistency, and non-mobile. She also experienced pressure-related symptoms, including constipation and shortness of breath, which increasingly interfered with her daily activities and work as a cook. Notably, she did not report abdominal pain, vaginal bleeding, vaginal discharge, or urinary symptoms

She reported an unintentional weight loss of approximately 10 kg over the same period, despite no significant loss of appetite. Her dietary intake had changed, with reduced consumption of rice and a preference for bread and fruits. She remained physically active during this time.

Her medical history included a laparoscopic ovarian cystectomy performed ten years earlier and a known uterine fibroid. She attained menarche at 16 years and menopause at 49 years. She had been married for 24 years with minimal cohabitation and was uncertain regarding infertility. Her husband had passed away five years earlier due to complications of diabetes mellitus and hypertension.

Initially, evaluation by a general practitioner is conducted, followed by referral to the hospital. Tumour markers showed elevated CA 125 (172 U/mL), CA 19-9 (432 U/mL), and carcinoembryonic antigen (CEA) of 5.9 ng/mL.

The ultrasound reported a right ovarian tumour 15x18cm in size with mixed echogenicity. [Fig. 1] Computed tomography (CT) of the thorax, abdomen, and pelvis demonstrated a large heterogeneously enhancing right adnexal solid-cystic mass, likely ovarian in origin, with a bulky uterus containing multiple fibroids. No outright evidence is found for distant metastasis.

She underwent exploratory laparotomy with total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and appendicectomy on 7 February 2025. Cytological examination of the peritoneal fluid revealed atypical cells suspicious for malignancy.

Histopathological analysis revealed a right ovarian tumour composed of malignant cells arranged predominantly in solid sheets with focal papillary architecture. The papillae were lined by hobnail to cuboidal cells. Immunohistochemistry showed tumour cells positive for Napsin A and CK7. These findings were consistent with ovarian clear cell carcinoma, FIGO stage IC.

Fig 1. Transvaginal ultrasound finding.

She commenced adjuvant chemotherapy in March 2025. Adverse effects included alopecia and peripheral neuropathy, predominantly affecting the lower limbs. She was admitted in April 2025 for her second cycle of chemotherapy.

DISCUSSION:

Ovarian clear cell carcinoma is a rare case nevertheless it is clinically significant subtype of epithelial ovarian cancer. Unlike high-grade serous carcinoma, it often presents as a large unilateral mass and may be associated with elevated CA 19-9 levels, as seen in this case.^{2 &3}

Weight loss and pressure symptoms are recognised but nonspecific features, often contributing to delayed diagnosis.

The pathogenesis of OCCC has been strongly linked to endometriosis, with molecular studies demonstrating frequent ARID1A mutations and activation of the PI3K/AKT pathway^.3&6 Although this patient did not have a documented history of endometriosis, her prior ovarian surgery and fibroid uterus may have contributed to diagnostic complexity.

Early-stage disease (FIGO stage I–II) generally carries a more favourable prognosis compared to advanced-stage OCCC; however, recurrence remains a concern even in stage I disease.^1&5 Inclusive surgical performance remains the keystone of management. Standard adjuvant chemotherapy with platinum-based regimens is commonly administered, although OCCC exhibits relatively chemoresistance compared to other epithelial subtypes.^3&4

Recent studies have explored the role of targeted therapies, including immune checkpoint inhibitors and agents targeting angiogenesis and molecular pathways, offering potential future therapeutic options to prevent risk for recurrence long-term follow-up is necessary.⁴

CONCLUSION:

This case illustrates the clinical presentation, diagnostic evaluation, and management of ovarian clear cell carcinoma in a postmenopausal woman presenting with a rapidly enlarging abdominal mass. Despite early-stage diagnosis, OCCC poses significant therapeutic challenges due to its aggressive biology and limited chemosensitivity. Prompt recognition, optimal surgical management, and ongoing advances in targeted therapies are crucial to improving outcomes in this rare ovarian malignancy.

CONSENT:

Written informed consent was obtained from the patient to publish and images for this case report.

CONFLICT OF INTEREST:

No conflict of interest between authors.

DECLARATION of COMPETING INTEREST:

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.

REFERENCES:

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5. Rahul K, Ranjith S, Muralee M, et al. Clear Cell Carcinoma of the Ovary with Isolated Contiguous Hepatopulmonary Metastasis. Indian J Gynecol Oncol. 2024; 22(3): 102.

6. Yin D, Jiang YJ. Case Series and a Literature Review: Two Ovarian Clear Cell Carcinoma Cases with Recurrent Endometriosis. Int J Womens Health. 2023: 1611–1619.

Received on 24.09.2025      Revised on 30.12.2025

Accepted on 22.02.2026 Published on 03.04.2026

Available online from April 06, 2026

Research J. Pharmacy and Technology. 2026;19(4):1849-1851.

DOI: 10.52711/0974-360X.2026.00265

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