[Spheroid formation in explants of human breast tumor and fibroadenomatous tissues and lymphoid infiltration of explants during cultivation in diffusion chambers].

An extensive formation of epithelioid cell spheroids was shown during tumour tissue growth on millipore filters. In addition, the appearance of such multicellular structures as an early sign of malignant transformation was demonstrated in some fibroadenomatous tissue cultures. The increased fibroadenomatous tissue proliferative activity was accompanied by the rising level of lymphoid cell infiltration.