Medullary sinuses and medullary cords in a lymphatic nodule (400X)

The medullary cords contain B lymphocytes, plasma cells and macrophages. In all areas of the lymph node we find endothelial cells (which belong to both the blood vessels and the medullary sinus) as well as fibroblasts, but these are not easy to distinguish from the other cells, as the cell density is high and these cells represent a minority.