Ultrastructural features of the blood cells in a patient with Pelger-Huët anomaly

A case of congenital Pelger-Hüet anomaly of the peripheral blood cells is described. Electronmicroscopic examination of the blood cells revealed nuclear bridges and appendices in the polymorphonuclear leukocytes. The number of cytoplasmic granules was diminished, but the size of the secondary granules was markedly increased. The eosinophils showed pronounced polymorphism of the granules, and the platelets showed a decrease in the alpha-granulomere number.