Auto-rosette formation in the peripheral blood of a patient with infectious mononucleosis.

Auto-rosette formation by peripheral blood lymphocytes was observed in a patient with infectious mononucleosis (IM), with the scanning electron microscope (SEM). The red blood cells adhered to lymphocytes with numerous microvilli on their surface. This phenomenon was observed only during the acute stage of the disease and not in the recovery period. Auto-rosette formation was detected neither in 7 other patients with IM, nor in control subjects.