The cells labeled P are Plasma cells. Note the nucleus which is off-center and
the dense cytoplasm which, at the EM level, is loaded with rough endoplasmic
reticulum. The nuclear heterochromatin is often in a "cartwheel" pattern.

Two more plasma cells (P) are shown in this field. One shows the
cartwheel nucleus well. Also, note three macrophages which are
detected by their content of injested black deposits. Perhaps this
came from a lymph node near the lung (of a smoker). The cell labeled
E is an Eosinophil.