HLA-antigen distribution in seminoma, HCG-positive seminoma and non-seminomatous tumours of the testis.

Histocompatibility antigens play a certain role in the development of testicular tumours. 151 patients with testicular cancer (86 non-seminomatous germ cell tumours--NSGCT--and 65 pure seminoma) were typed for the HLA-antigens of the A, B, C and DR locus. 24 patients of the pure seminoma group and 50 patients of the NSGCT group had an elevated serum HCG level preoperatively. The antigen DR-5 was elevated in the seminoma group whereas the incidence of B-13 was increased in the NSGCT group. In terms of antigen distribution HCG-positive seminoma resembles seminomatous tumours rather than NSGCT.