Segmented neutrophil Information and Courses from MediaLab, Inc.

Two segmented neutrophils and a lymphocyte (indicated by an arrow) are in the center of this picture. Notice the mature chromatin structure in the nucleus of the lymphocyte. Three mature red cells are present around the lymphocyte. Two macrophages are also present in this picture.

The abundant cytoplasm of a segmented neutrophil is of virtually the same appearance as that of the band. It stains faintly pink and contains numerous fine specific granules which are pinkish-lilac.

Any cell of the granulocytic series which has a nucleus that could be described as a curved or coiled band, no matter how marked the indentation, if it does not completely segment the nucleus into lobes connected by a filament, is considered a band form.It is differentiated from the segmented neutrophil by having no indentation which could be described as a filament.

The nucleus is a deep reddish-purple color, and the chromatin has a coarse, clumped texture.The seg nucleus normally has from 2-5 lobes, with an average of 3.The lobes are connected to each other by a fine filament or strand of nuclear membrane.A filament has been defined as a thread-like strip which is so narrow that there is no visible nuclear material between the two sides.

A normal bone marrow smear stained with Wright/Giemsa stain is captured in this photograph.Note the normal maturation sequence beginning with myelocytes (the two large cells in the left upper corner)through metamyelocytes, band neutrophils,and multi-lobed segmented neutrophils.The small cells with darkly staining, centrally placed nuclei are normoblasts (three are clustered in the left lower field).Absent in this field are eosinophils, basophils and megakaryocytes.A normal M:E ratio of 2.4:1 is calculated from the twelve myeloid cells and five normoblasts. Two lymphocytes are identified, one left center, the other left upper.

A 14 year-old boy came to the physician's office with a sore throat that progressively worsened over a three day period. His posterior pharynx was swollen ,shiney and erythematous. The boy complained of pain on swallowing. His temperature was 98.5F. A rapid direct streptococcal antigen test was positive. However, his symptoms did not subside over the next two days while on antibiotic therapy. Anorexia and nausea were persistent and compounded by a frontal headache. Cervical lymph nodes became noticeably enlarged. The results of the CBC were: WBC 11.9/mm3 with 17% segmented neutrophils, 5% bands, 72%(60% atypical--see photograph)lymphocytes and 6%monocytes. All red cell findings were normal. A monospot test was positive. This is a case of group-A streptococcal infection superimposed on infectious mononucleosis. Symptoms subsided in 3 weeks following completion of the antibiotic therapy.