Malignant transformation of vaginal adenosis to clear cell carcinoma without prenatal diethylstilbestrol exposure: a case report and literature review

BACKGROUND: We report an extremely rare case of vaginal clear cell carcinoma, which originated from the malignant transformation of vaginal adenosis without prenatal diethylstilbestrol (DES) exposure. CASE PRESENTATION: In this case, the patient was a Chinese woman with a history of two decades of intermittent vaginal pain, sexual intercourse pain and vaginal contact bleeding. On September 1, 2011, when the patient was 39 years old, a vaginal biopsy revealed vaginal adenosis. After intermittent drug and laser treatment, her symptoms did not improve. Four years later, on March 4, 2015, another vaginal biopsy for abnormal vaginal cytology revealed atypical vaginal adenosis. After treatment with sirolimus, her symptoms and abnormal vaginal cytology results persisted, and she underwent laparoscopic hysterectomy with bilateral salpingo-oophorectomy and excision of the vaginal lesions. One year after the hysterectomy, on August 15, 2017, the vaginal cytology results suggested atypical glandular cells, and a biopsy revealed vaginal clear cell carcinoma originating from the atypical vaginal adenosis. A wide local resection of the vaginal lesions was performed, followed by concurrent chemoradiotherapy. Regular follow-up over 16 months showed no evidence of the recurrence of vaginal adenosis or cancer. CONCLUSIONS: Based on the evolution of a series of pathological evidence, we report the fourth case in the world of vaginal clear cell carcinoma originating from vaginal adenosis without prenatal DES exposure. Wide local excision with radiotherapy provided at least 16 months of disease-free survival.