Hypersegment

Hypersegment refers to a condition where the neutrophils, a type of white blood cell, in the blood exhibit an abnormally increased number of nuclear lobes. Normally, neutrophils have a nucleus with two to five lobes. In hypersegmentation, this number can be six or more. This morphological change is observed in peripheral blood smears under a microscope.

The most common cause of hypersegmented neutrophils is vitamin B12 or folate deficiency. These vitamins are essential for DNA synthesis and cell division, and their deficiency can lead to impaired maturation of neutrophil nuclei. Other causes of hypersegmentation include myelodysplastic syndromes, a group of disorders where the bone marrow fails to produce enough healthy blood cells. Certain chronic infections and inflammatory conditions can also sometimes be associated with hypersegmented neutrophils, though this is less typical.

Diagnosing hypersegmentation involves a complete blood count (CBC) with differential, which quantifies the different types of white blood cells and assesses their morphology. If hypersegmented neutrophils are noted, further investigations are usually warranted to identify the underlying cause, which may include checking vitamin B12 and folate levels or a bone marrow biopsy. Treatment focuses on addressing the root cause, such as vitamin supplementation for deficiencies or specific therapies for myelodysplastic syndromes.