OverviewThis picture shows large, atypical lymphocytes (white blood cells). These cells are seen in viral infections, most commonly caused by the Epstein-Barr virus (infectious mononucleosis), cytomegalovirus diseases, and occasionally infectious hepatitis. This is an example of a type I Downy cell.
Review Date 2/15/2016
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.