Neutrophil dysplasia (acquired pseudo-pelger anomaly) caused by ganciclovir.

Two thoracic organ-transplant recipients with persistent cytomegalovirus infection developed morphologic abnormalities in their circulating neutrophils while receiving either ganciclovir or its prodrug valganciclovir. Neither patient was receiving concomitant treatment with mycophenolate mofetil or azathioprine. In both patients, the morphologic abnormalities preceded the development of neutropenia and bone-marrow hypoplasia. The morphologic changes most likely reflected interference of DNA polymerization within bone marrow progenitor cells. The changes resolved completely after the drug was withdrawn.