Collection of atypical forms that lymphocytes can take on in response to viruses, bacteria or other forms of inflammation. However, a dominant presentation of one type of abnormality may still be malignant. Always watch for monotonicity and whether the rest of the blood count fits; with infection or inflammation, other cell lines also show signs of activation and the CRP or sedimentation rate may be elevated. Clinical presentation (signs of infection, fever) may also play a role.