Prognosis of eight Chinese cases of primary vaginal yolk sac tumor with a review of the literature.

Background: Primary vaginal yolk sac tumor is a rare malignancy in the pediatric population, and a diagnostic challenge and appropriate initial treatment remains unsolved. The aim of this study was to investigate the clinicopathologic features, treatment and prognosis of this tumor. Materials and Methods: Eight cases of primary vaginal yolk sac tumor were reported with a literature review. Results: There were 4 pure yolk sac tumor cases and four mixed germ cell tumors containing yolk sac tumor element, including two cases with embryonal carcinoma and two cases with embryonal carcinoma and dysgerminoma. Partial vaginectomy was performed in four cases and all patients received chemotherapy. 85 cases in literatures were reviewed and 9 cases were misdiagnosed. Follow-up data was available in 77 cases and 5-year overall survival rate was 87.6%. 5-year survival rate of biopsy with chemotherapy, conservative surgery with chemotherapy and radical surgery with chemotherapy was 91.1%, 100% and 28.6%, respectively (p<0.001). Compared to cases without relapse or metastasis after initial treatment, patients with relapse or metastasis had a shorter overall survival (35.6% vs 96.6%, p<0.001). Conclusions: Mixed germ cell tumor containing yolk sac tumor element was not uncommon and partial vaginectomy may be a good choice for primary vaginal mixed yolk sac tumor type to eradicate local tumor cells and provide complete information for pathological diagnosis and postoperative adjuvant therapy.