Pseudoleukemia. Ineffective regulation of granulopoiesis.
A neonate with Down's syndrome confirmed by chromosomal analysis had leukocytosis, with a WBC count of 48,000/cu mm, at age 13 days. Differential counts showed 70% to 90% blast forms by light microscopy. The blast-cell granules stained negatively with Sudan black B and alpha-napthyl butyrate esterase. Myeloperoxidase activity evaluated light and electron microscopy was negative. The granules stained positively with PAS, beta-glucuronidase, and tartrate-sensitive acid phosphatase. Indirect immunofluorescence for terminal-deoxynucleotidyl-transferase was negative. Our results show that the blast cells of pseudoleukemia may be of lymphoid origin.
D001854:Bone Marrow Cells; D004314:Down Syndrome / Q000473:pathology; D006098:Granulocytes / Q000473:pathology*; D006410:Hematopoiesis; D006689:Hodgkin Disease / Q000473:pathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D007964:Leukocytosis / Q000473:pathology; D008854:Microscopy, Electron; D009504:Neutrophils / Q000473:pathology