Hypersegmented neutrophils may be seen in a few conditions. Most often hypersegmented neutrophils are associated with megaloblastic anemia and are said to be pathognomonic of the disease. Megaloblastic anemia can be caused by folic acid deficiency or vitamin B12 deficiency (including pernicious anemia). Hypersegmentation of neutrophils may also be seen in myelodysplastic syndromes, when receiving chemotherapy, or in long-term chronic infections.
The cells seen in these conditions would be classified as pathological since the body is responding abnormally as a result of either a deficiency of a component needed for DNA production or because of the toxic effect that chemotherapy drugs have on DNA.
A hypersegmented neutrophil showing seven segments is present in this image (see arrow).
