[Ultrastructure of breast cancer vessels]

Vascular bed of the infiltrating mammary gland carcinomas characterized by the incomplete maturity, atypia and polymorphism is studied electron microscopically. Two groups of vascular structures were investigated: avascular part represented by pseudovessels and vascular part with protocapillaries, capillaries, sinusoids and venulae that are distinguished by their morphofunctional properties and the degree of maturity. The vascular bed is characterized by a structural and functional heterogeneity. Ultrastructural properties characterizing the stages of the vascular bed morphogenesis are presented: angiogenesis activation, relative vascular differentiation and regression of some parts which occur asynchronically and are due to the properties of the stromal parenchymal relations in different microareas, and to the heterogeneity of the tumour on the whole.