AbstractBackgroundThe association between non seminomatous germ cell tumors (GCTs) and hematological malignancies of rare lineage has been described in the literature. In some of these cases there is evidence that the leukemia derives from a pluripotent primitive clone present in the original germ cell tumor.Case presentationWe present a highly unusual case of a 23-year-old man of South Asian origin with a history of Klinefelter’s syndrome who initially developed mediastinal non seminomatous GCT. Following treatment with surgery and standard chemotherapy he went on to develop three different hematological malignancies of distinct lineages in sequential fashion over a short time period. Despite treatment with multiple intensive chemotherapy regimens and a matched unrelated donor allogeneic stem cell transplant, he died 41 months after initial diagnosis of his GCT and 10 months after the first diagnosis of hematological malignancy.ConclusionsThis is an extreme case that highlights the pluripotency and aggressiveness of these GCT-derived hematological malignancies, and the need for novel therapeutic approaches.