What do lymphocytes look like?

Under a microscope, lymphocytes typically appear as small, round cells slightly larger than red blood cells. Each tiny lymphocyte has a single, large, round, central nucleus that occupies most of the cell's volume. The nucleus is darkly stained and may be irregularly shaped or have a slightly indented appearance. Surrounding the nucleus is a thin cytoplasm layer, which houses small quantities of cellular organelles such as mitochondria and ribosomes.