A case of human herpesvirus-6 lymphadenitis with infectious mononucleosis-like syndrome.

The findings of a 20 year old woman with lymphadenopathy that was probably caused by an acute human herpesvirus-6 (HHV-6) infection are reported. She clinically demonstrated various signs of acute infection such as a high fever, skin rash, liver dysfunction, leukocytosis, an elevation of the erythrocyte sedimentation rate, and a positive change of C reactive protein, which mimicked the symptoms of infectious mononucleosis, but no positive titers for an Epstein-Barr virus infection were observed. HHV-6 DNA was detected using Southern blot analysis, polymerase chain reaction, and in situ hybridization in the affected node. Histologically, the lymph node showed an enlarged paracortex and infiltration of transformed lymphocytes and immunoblast-like cells with some histiocytes and eosinophils. Almost all the transformed lymphocytes and immunoblasts were positive for UCHL-1 (CD45RO), MT-1 (CD43), and OPD-4 (CD4), and some of these positive cells demonstrated HHV-6 DNA.