Fig. 7

Transmission electron microscopy of healthy and tumour mammary gland. a Representative image of tumour mammary tissue. The lobule centrally displayed an intercellular lumen (*) and an intracellular lumen (**) with numerous microvilli inside them. Myoepitalial cells (MI) were discontinuous and basement membrane was absent (arrows). b Magnification of panel a, where the intracellular lumen (**) and the intercellular lumen (*) with their microvilli were clearly distinguishable. c Magnification of panel a, where could be detected an intracellular lumen (**) in the basal position. Neither myoepithelial cells, nor basement membrane could be recognized (arrows). d Representative image of mitochondria (m) rich in cristae from tumour mammary tissue. N= nuclei. e Representative image of healthy mammary gland, where two mitochondria with peripheral ridges (arrows) were clearly evident. D = desmosome. f Representative image of a lobule, where two intercellular lumens (*) were detecable, as well as myoepithelial cells (MI) that continuously surrounded the lobule. g Magnification of f. The basement membrane (arrows) and myopithelial cells (MI) were identifiable