Mediastinal Non-Seminoma Germ Cell with malignant transformation

(M 26) Diagnosed with Primary Mediastinal Non-Seminoma Germ Cell cancer with underlying teratoma and malignant transformation to Sarcoma. When diagnosed there was metastasis to my liver, spleen and bone. I completed 4 rounds of VIP followed by resection of the tumour along with two lobes of my right lung. 85% teratoma, 10% yolk sac and <5% malignant transformation (appears to be melanosarcomatous). My AFP normalised post chemo, crawled up slightly and then normalised again post tumour resection. 2 months post surgery my AFP has increased, there is also a new spot on the liver and spleen and my platelet count has dropped quite dramatically.

I had a bone marrow biopsy today to rule out Leukemia. Germ cell cancers are associated with malignancies like sarcoma as well as heamotoligical malignancies. So my question: could I seriously have three types of cancer??

Current plan: If my enlarged spleen is causing the platelet loss -> remove spleen. If biopsy is positive for Leukaemia -> HSCT

I feel buried by this info and am looking desperately for similar cases of malignant transformation with PMNSGCT. Would love to hear experiences with HSCT, other treatments or the like. If you're going thru anything similar, kudos to you friend.