Mixed or metachronous germ-cell tumor?

Objective and Importance: We report the extremely rare occurrence of a second germ-cell tumor at a different site and with different histological types long after total resolution of a pineal germinoma.
Clinical Presentation: A 21-year-old man who presented with headache and diplopia was admitted to our hospital. Neuroradiological studies revealed a tumor in the pineal region. The tumor was biopsied with endoscope, and third ventriculostomy was performed. Histologically, the tumor proved to be a germinoma. The patient received 3 cycles of combination chemotherapy consisting of carboplatin and etoposide with radiotherapy. The tumor was totally resolute. Twelve months later, he was readmitted with headache and diplopia. Neuroradiological studies showed a tumor in the right temporal lobe.
Intervention: The second tumor was totally removed. Histologically, the tumor proved to be a mixed germ-cell tumor, which consisted a yolk-sac tumor and a germinoma. After the second course of chemotherapy, magnetic resonance image studies revealed no evidence of the tumor.
Conclusion: The second tumor was considered to be a metachronous neoplasm rather than a recurrence of the original mixed germ-cell tumor, which consisted a yolk-sac tumor and a germinoma.