Diagnosis, treatment, and long-term follow-up of a 13-year-old boy with a testicular mixed germ cell tumor (yolk sac tumor and embryonal carcinoma): a case report and literature review.

Testicular germ cell tumors (TGCTs) are rare in children under 15 years of age. We report the first documented case of a mixed yolk sac tumor and embryonal carcinoma in the left testis of a 13-year-old boy in the early stages of puberty (12-14 years). The patient presented with a left scrotal mass, markedly elevated serum alpha-fetoprotein and human chorionic gonadotropin levels, and ultrasonographic findings suggestive of a testicular tumor. Pathological confirmation was obtained after radical orchiectomy, with no recurrence or metastasis observed during 29 months of follow-up. This case report reviews the literature on histologically similar testicular tumors and summarizes diagnostic and management experiences. For testicular mixed germ cell tumors in early adolescence, immediate radical orchiectomy can achieve clinical cure, and long-term follow-up is crucial.