'Myelokathexis'. Neutropenia with marrow hyperplasia
S. O'Regan, A. J. Newman and R. C. Graham
A 10-year-old girl was first seen at age 5 years with pneumonia and
neutropenia. Since then, she has remained leukopenic, although manifesting
a leukocytosis only when she has pulmonary infection. A rapid fall in her
peripheral WBC count occurs with initiation of antibiotic therapy. Despite
her neutropenia, marked myeloid hyperplasia is evident on marrow smear
examination; many cells being hypersegmented with fine intralobular
bridging with chromatin strands and cytoplasmic vacuolation. The peripheral
WBC response to epinephrine adminstration did not indicate a shift from the
circulating to marginal neutrophil pool. Results from a Rebuck skin window
test suggested poor neutrophil tissue migration. A defect in granulocyte
release from the patient's marrow may explain these bizarre hematologic
findings.
