Pelger-Huet anomaly

Pathology

• failure of normal segmentation of granulocytic nuclei
• apparently looser chromatin structure of neutrophils
• heterozygotes show hypolobulated neutrophil nuclei with coarse chromatin
• presumed homozygous individuals have ovoid neutrophil nuclei

Genetics

• autosomal dominant
• associated with defects in LBR

Clinical manifestations

• heterozygotes are asymptomatic
• presumed homozygous individuals show varying degrees of developmental delay, epilepsy, & skeletal abnormalities

Laboratory

• peripheral blood smear
  • bilobed neutrophils are abundant; these are not normal band forms, but mature neutrophils; they are functionally normal neutrophils
• in the acquired form, mature neutrophils with round, non-segmented nuclei may also be found
• Pelger Huet cells in blood
• pseudo Pelger Huet cells in blood

Differential diagnosis

• similarly appearing bilobed neutrophils resulting from an acquired disorder of granulocytic nuclear segmentation may occur with:
  • granulocytic leukemia
  • myeloproliferative disorders
  • myelodysplastic syndrome
  • some infections
• certain drugs
• neutrophilic band

More general terms

• congenital anomaly (birth defect)
• abnormal morphologic structure (malformation)