Concurrent development of testicular seminoma and choriocarcinoma of the superior mediastinum, presented as cervical mass: a case report and implications about pathogenesis of germ-cell tumours

The pathogenesis of concurrent germ cell tumours in the same patient remains an area of controversy. Although the genetic instability of the pluripotent germ cell offers an adequate explanation, the possibility of metastasis from the primary, less differentiated tumour to a distant location as a more mature subtype cannot be excluded. Possible development of a metastatic site of different histology and thus biological behaviour (e.g choriocarcinoma) should be anticipated. Furthermore, urologists, pathologists and medical oncologists should be meticulous in the original pathological diagnosis in these patients, since there is a significant frequency of germ cell tumours with mixed or overlapping histological elements with diverse potential of evolution and differentiation.