Ultrastructural observations on the cytomegalic inclusion cell in peripheral blood

A 31-year-old woman with adult T-cell leukemia developed interstitial pneumonitis. Large abnormal cells different from those of adult T-cell leukemia appeared in the peripheral blood. Hematoxylin-eosin staining of the buffy coat of peripheral blood revealed these cells to be cytomegalic inclusion cells. Electron microscopy disclosed cytomegalovirus particles in these inclusion cells. Virus particles were seen in both the nuclei and cytoplasm. Dense bodies characteristic of cytomegalovirus infection were also seen in the cytoplasm. This is the first report of cytomegalovirus particles found in the peripheral blood mononuclear cells.