Large Lymphocyte

Large lymphocyte from a normal blood film.  It is a larger cell than the small lymphocyte, with more abundant and somewhat granular cytoplasm.  A small lymphocyte, B-cell or T-cell, becomes a large lymphocyte as it is stimulated to proliferate.  Such a cell can be shown to be able to incorporate tritiated thymidine, a marker of active DNA synthesis. 

The remainder of the field is occupied by red blood cells (RBCs).