[Microvasculature of retrosternal lymphoid and adipose structures in the child].

The study of young children's retrosternal lobular formations allowed us to distinguish different structures: lymph nodes, adipose lobules, and variable lymphoid formations. The arteries of the lymph nodes are either medullar, cortical or perforating, and the venous net is characterized by existence of perifollicular cortical corbels. The adipose lobules are often made of a mingling of white fat tissue and foetal fat tissue, and in the zones of foetal fat the vascular network is the most developed. The lymphoid formations are of variable structure and microcirculation. Some of them are represented by foetal fat lobules with scattered lymphoid cells, their microvascularization is comparable to microcirculation of fat tissue. Others, are characterized by few lymphoid cells and by development of the connective and reticular tissue; there, the anastomotic venous network is very dilated. Some formations are like lymph nodes, but their sinusal spaces are full of erythrocytes and their microcirculation is peculiar.