Histo-blood group antigens as differentiation markers in testicular germ cell tumours

The distribution of histo-blood group antigens in a series of eleven human non-seminomatous testicular germ cell tumours is described and the variable expression of these antigens is related to the patterns of differentiation that are reflected morphologically within these tumours. The results suggest that histo-blood group antigens of type 2 chain carbohydrate structures may be used as markers of differentiation. All the tumours contained binary 2-3 sialosyllactosamine structures. N-acetyllactosamine and Le(y)-negative tumors were the least differentiated morphologically, while N-acetyllactosamine and Le(y)-positive tumours exhibited more differentiated tumour patterns. Whether the occurrence of the latter antigens in poorly differentiated forms of germ cell tumours reflects a biological potential for differentiation remains to be proven in a larger material.