RESUMO
BACKGROUND: Wilms' tumor is the second most common pediatric abdominal cancer; however, it rarely involves the female reproductive tract. There are few cases reported in the literature describing uterine, ovarian, cervical, and vaginal involvement. CASE: We report the case of a 7-year-old girl presenting with a large renal mass with retroperitoneal nodal and lung metastases; she was diagnosed with stage 4 favorable histology Wilms' tumor. She was treated with surgery, chemotherapy, and radiation. She presented with vaginal bleeding 10 months after completing treatment; biopsy of a vaginal mass confirmed recurrence, and this was sent for molecular profiling, which did not identify an inherited cancer predisposition or targetable mutation. She was again treated with chemotherapy; examination redemonstrated a small vaginal mass, but re-biopsy of the lesion was negative for malignancy. Due to high risk of local relapse, ongoing chemotherapy and pelvic radiation ensued. End-of-treatment imaging and vaginoscopy showed no residual disease. SUMMARY AND CONCLUSION: Vaginal metastases of Wilms' tumor are very rare; this is the second reported case in the literature. Pediatric clinicians should have a strong suspicion for vaginal metastases in cancer patients presenting with vaginal bleeding, especially when their pubertal development does not suggest that bleeding would be secondary to menarche. Long-term gynecologic care for these patients is paramount to reduce morbidity from chemotherapy and pelvic radiation. Fertility preservation counselling should be made early, through referral to a specialist.