Clear-Cell Endometrial Cancer: From Puzzling Diagnosis to Battle-Ready Plan
A Subtle Warning Becomes a Siren
A 55-year-old retired administrator, living alone and generally healthy, first noticed light spotting nearly two years after her last period. The bleeding—dismissed at first—grew heavier and more frequent over five months until it became constant. She had been sexually inactive for 12–24 months and, aside from a dry cough and occasional 37.5 °C fever in the previous fortnight, felt well.
Gynecologic background
First period at 12 years, menopause at 53 years
No hormone-replacement therapy
Two adult children
No prior surgeries, hospitalizations, or chronic illnesses
The Misleading First Diagnosis
At a regional hospital, pelvic ultrasound suggested a uterine fibroid; adenomyosis and a submucosal myoma were also considered. Laboratory results painted a different picture:
CA-125: 87.8 U/mL (above the 35 U/mL limit)
CA-19-9: 549.5 U/mL → 948 U/mL within one month (dramatic rise)
CEA: 1.42 ng/mL (normal)
Hemoglobin: 13.3 g/dL
Despite the red-flag tumor markers, she underwent a hysteroscopic “fibroid” resection. Pathology was unequivocal: clear-cell carcinoma (CCC), a rare, highly aggressive endometrial cancer. She sought a second opinion from Dr. Chung-Te Wang at Koo Foundation Sun Yat-Sen Cancer Center.
Tumor-Board Reality Check
Persistent post-menopausal bleeding should always raise suspicion for endometrial malignancy. Elevated CA-125 and CA-19-9 strengthened that suspicion; proceeding with intra-uterine surgery before ruling out cancer risked disseminating disease. Over-use of hysteroscopy—sometimes driven by generous reimbursement or self-pay options—remains a system issue, and the principle of Do No Harm must prevail, even when late-stage disease seems likely.
Imaging Redefines the Stage
Pelvic MRI: enlarged uterus dotted with multiple fibroids; endometrial cavity distended by abnormal tissue.
PET-CT: tiny right-lung nodule; 0.7 cm FDG-avid nodule in the left upper lung (suspicious for malignancy); moderate FDG uptake in the left thyroid lobe (probable nodule).
Conclusion: Stage IV clear-cell endometrial carcinoma with suspected pulmonary metastasis—consistent with the rapid rise in CA markers.
Comprehensive Treatment Blueprint
Step 1 — Confirm each hot spot
• Biopsy lung and thyroid nodules for definitive pathology.
Step 2 — Map the battlefield
• Complete staging, then plan systemic therapy—chemotherapy or immunotherapy—before any further surgery.
• Evaluate how much tumor can be safely removed.
Step 3 — Team decision: extensive staging surgery
After multidisciplinary debate, the team proceeded with:
• Total hysterectomy
• Bilateral salpingo-oophorectomy
• Pelvic and para-aortic lymph-node dissection
• Wedge resection of the left-upper-lobe lung nodule (thoracic surgery)
Surgery went smoothly. Adjuvant chemotherapy is scheduled; the goal of the operation was maximal cytoreduction—shrinking disease burden to improve drug efficacy while securing final pathology.
Clear-Cell Endometrial Carcinoma at a Glance
Rarity and classification
Clear-cell carcinoma accounts for 5–10 % of endometrial cancers but is classified as Type II because of its aggressive nature and poorer prognosis.
Pathology and molecular traits
Cells appear “clear” under the microscope due to glycogen-rich cytoplasm.
Usually lacks PTEN, KRAS, and MSI-high mutations.
Frequently harbors p53 mutations.
Key risk factors
Post-menopausal age (peak 60–70 years)
Long-term anti-estrogen therapy (e.g., tamoxifen)
Previous pelvic radiation
Lynch syndrome and other hereditary cancer syndromes
Typical presentation
Post-menopausal vaginal bleeding is the hallmark.
Pelvic or abdominal pain may signal advanced spread.
Diagnostic arsenal
Imaging: pelvic ultrasound, MRI, PET-CT
Endometrial biopsy with classic clear-cell histology
Immunohistochemistry: p53 and HNF1-beta positive; ER/PR negative
Treatment and outlook
Aggressive surgery plus adjuvant chemotherapy and, often, radiotherapy
Five-year survival lags behind Type I cancers; recurrence risk remains high