The Granulation Score (G-Score) of Widell et al for neutrophils correlates with the degree of dysplasia in patients with a myelodyplastic syndrome. The G-score from the peripheral blood smear provides information that complements that provided by examination of the bone marrow. The authors are from Karolinska, Huddinge and Danderyd Hospitals in Stockholm.


The G-score can be determined on either the bone marrow or the peripheral blood smear. The G-scores for bone marrow and peripheral blood show a linear relationship, as shown in Figure 2 (Widell et al, page 118).

Neutrophilic Granulation


clearly visible granules covering the entire cytoplasm


faintly colored granules or with less than two thirds of cytoplasm covered


rare or few granules


agranular with no visible cytoplasmic granules




• The criteria for Grade 1 was not described in the text but was shown in Figure 1 (Widell et al, page 116).


G-score =

= SUM(granulation grades for 100 neutrophils)



• minimum G score: 0

• maximum G score: 300

• The normal G score is >= 255.

• A G score < 150 indicates extreme hypogranulation and tends to be seen in patients with bi- or tri-lineage dysplasia in the bone marrow.

• Patients with lower G scores tend to have an increased percentage of myeloblasts in the bone marrow biopsy.


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