Primary mediastinal germ cell tumor in an 88-year-old man managed with carboplatin monotherapy and radiotherapy

Mediastinal seminoma is a rare extragonadal germ cell tumor that predominantly affects young adults. Cisplatin-based chemotherapy is the standard treatment; however, its use in elderly patients is often limited by age-related factors and organ dysfunction. We report the case of an 88-year-old man with a rapidly enlarging mediastinal seminoma who was managed with carboplatin monotherapy followed by radiotherapy. Three cycles of carboplatin (first cycle AUC 5.6; subsequent cycles up to AUC 7) were administered, resulting in initial tumor regression, followed by disease progression after the third cycle. Salvage radiotherapy achieved marked tumor shrinkage with normalization of lactate dehydrogenase levels and durable disease control. At 19 months after treatment initiation, the patient remains alive with stable disease. This case suggests that carboplatin-based chemotherapy followed by radiotherapy may represent a pragmatic treatment option for elderly patients with mediastinal seminoma who are unsuitable for cisplatin-based regimens.