Objectives. Primary mediastinal germ cell tumors (PMGCTs) are rare, which often makes them difficult to treat. Herein, we examined patients with PMGCTs who underwent multimodal treatment. Methods. We examined 6 patients (median age: 25 years, range: 19-27 years) with PMGCTs who underwent multimodal treatment between April 2001 and March 2015. Three patients had seminomas, 2 patients had yolk sac tumors, and 1 patient had choriocarcinoma. The median observation period was 32.5 months (range: 8-84 months). Results. Three of the 6 patients received initial operation followed by 3-4 courses of chemotherapy (bleomycin, etoposide, and cisplatin (BEP) or etoposide and cisplatin (EP)). One patient developed multiple lung metastases 17 months after surgery
received salvage chemotherapy with vinblastine, ifosfamide, and cisplatin
and achieved complete remission. The remaining 3 patients received initial BEP and EP chemotherapy. Multiple lung metastases and supraclavicular lymph node metastases were detected in 2 of these patients at the initial diagnosis. The patients underwent resections to remove residual tumor after treatment, and no viable tumor cells were found. Conclusions. Reliable diagnosis and immediate multimodal treatments are necessary for patients with PMGCTs. The 6 patients treated in our hospital have never experienced recurrence after the multimodal treatment.