Reactive lymphocytes

They used to be called atypical lymphocytes. These large lymphocytes may be increased in the peripheral blood smear in certain inflammatory conditions such as an underlying viral infection (e.g. EBV induced mononucleosis, the lymphocytes look so large that they start resembling monocytes). They usually have increased amount of cytoplasm which wraps or hugs the surrounding RBCs. Reactive lymphocytes are typically CD8+ T-cells.