Pelger-Huet Anomaly (Fig. ioa-c)
This is an inherited anomaly involving the nuclei of granulocytes. The heterozygous form predominates in man while the homozygous form, characterized by small round or oval nuclei (Fig. 10 c), is extremely rare. The nucleus of neutrophils is indented and resembles the band form, giving rise to a "pseudoregenerative" white blood picture. When nuclear segmentation (lobulation) occurs, the neutrophils acquire two nuclear lobes and rarely three. These lobes are exceptionally short, thick, and chromatin-rich. Pelger myelo-cytes and band forms also have very coarse, clumped nuclei rich in chromatin. The patient is classified as a full carrier if all neutrophils are affected by the anomaly and a partial carrier if normal band and segmented forms are also pre sent. The Pelger-Huet anomaly is harmless in its effect on leukocyte function. Severe infections and particularly myelodysplasias, acute myeloid leukemia, and advanced chronic myeloid leukemia can produce transient, qualitatively similar changes in white cell nuclei, creating what is known as "pseudo Pelger-Huet forms."
Here the granulocytes contain large, bluish granules that often resemble those of promyelocytes; monocytes have large granules, too. The abnormal granulation is especially marked in eosino-phils, which appear basophilic rather than eosino-philic (Fig. 10 e, left). The lymphocytes also contain particularly large azurophilic granules (Fig. 10 f). Carriers of this anomaly frequently have associated bone and joint deformities (gar-goylism). The anomaly is known to occur in mucopolysaccharidosis VI and VII.
This condition affects virtually all leukocytes. The neutrophils contain irregular, grayish-blue cytoplasmic inclusions 1-3im in diameter. These bodies are sharply demarcated and contain per-oxidase and also CE in some cases, identifying them as primary granules (Fig. 11 a, b, e, f). The granules of eosinophilic leukocytes are also enlarged to 2 - 3 times the size of normal eosino-philic granules. They are round to oval in shape and variable in size. Most lymphocytes and mono-cytes also contain intensely red-staining granules 1-2 im in diameter. The inclusions in the monocytes are 5 im in diameter and stain pink (Fig. 11 d). In the bone marrow, red-violet bodies
1-3 im in diameter can be demonstrated in semi-mature and mature cells starting with the promyelocytes. In addition, the myeloblasts and myelocytes frequently contain large vacuoles in which a large, round inclusion is often found (Fig. 11 c-f). Phase contrast and electron microscopy reveal coarse cytoplasmic inclusions of a pleomorphic structure in neutrophils and eosino-phils, lymphocytes, and even in erythroblasts. There is further evidence indicating that the disease is based on a defect in the lysosomal membrane. This pathogenic disturbance, which exerts its major biochemical effect on glycolipids, affects not only the blood cells but other organs as well and thus cannot be considered innocuous. Affected individuals usually die at an early age.
May-Hegglin Anomaly (Fig. 12 a-d)
This disorder has an autosomal dominant mode of inheritance and is associated with mild leukopenia and thrombocytopenia. The neutrophilic granulocytes contain predominantly rod-shaped inclusions of a pale- to dirty-blue color, approximately 2-5 im in diameter, which are found on electron microscopy to consist of dense RNA fibrils and are distinguishable from the Dohle bodies that occur in severe infections. The inclusions also occur in monocytes and eosinophils, but they are very difficult to detect in these cells. They can be selectively demonstrated with methyl green-pyronine stain (red) (Fig. 12 a, b). Giant platelets are also detected (Fig. 12 c). There is one reported case (H.L.) in which bone marrow examination revealed a coarse, nonhomogeneous clumping of granules in the cytoplasm of the megakaryocytes (Fig. 12 d).
Was this article helpful?