Toxic granulation is manifested by the presence of large granules in the cytoplasm of segmented and band neutrophils in the peripheral blood. The color of these granules can range from dark purplish blue to an almost red appearance. Toxic granules are azurophilic granules, ordinarily present in early myeloid forms, but are not generally seen at the band and segmented stages of neutrophil maturation. These granules contain peroxidases and hydrolases.
Toxic granulation is seen in cases of severe infection due to denatured proteins in rheumatoid arthritis or, less frequently, due to autophagocytosis. Infection is the most frequent cause of toxic granulation. This phenomenon may be seen in cells containing Döhle bodies and/or vacuoles. Cells containing toxic granules may have decreased numbers of specific granules.
Note: Cells containing only a few specific granules, with or without toxic granules, are said to be degranulated. The nucleus in degranulated cells may often be round-bi-lobed, smooth, and pyknotic. This type of nucleus is the result of aging and will disintegrate soon. Increased basophilia of azurophilic granules simulating toxic granules may occur in normal cells with prolonged staining time or decreased pH of the stain.
The blue arrow in the image points to a neutrophil with toxic granulation. Döhle bodies, indicated by the red arrows, are also present in the cell.
