Melano-macrophage centres in liver and spleen of ruffe(Gymnocephalus cernua) from the Elbe Estuary

Macrophages with yellow or black deposits of melanin occur singly or in groups in the melano-macrophage centres are functionally the primitive analogues of lymph nodes in birds and mammals. From 1980 to 1982, tumours and pretumorous tissue changes in ruffe from the Elbe Estuary were studied. Pathological alterations occur mainly in the liver and spleen. In connection with both, neoplastic abnormalities in liver and spleen, and fatty degenerative processes in the liver, an obvious increase in number and size of the melano-macrophage centres was observed. The colour, structure and some histochemical properties of melano-macrophage centres in the liver differ somewhat from those in the spleen. The majority of splenic centres were filled with large amounts of haemosiderin, whereas many hepatic macrophages contained fatty inclusions. Possible differences in the functions of splenic and hepatic melano-macrophage centres are discussed.