New York State Department of Health - Wadsworth Center - Cytohematology Proficiency Testing

Slide E04 [100X]        Click here for a higher resolution image.

This educational (ungraded) slide is from an 89 year old male with peripheral hemophagocytosis. The arrowed inclusion within the segmented neutrophil is a platelet (code: 51). Another phagocytized platelet is visible to the immediate right of the arrowed inclusion. Peripheral phagocytosis of platelets (hemophagocytosis) is not commonly observed.

A recent article by Kuwata, K, et al suggests that the observation of peripheral hemophagocytes can be a useful indicator for early diagnosis of hemophagocytic syndrome (Hemophagocytic syndrome with hemophagocytes in the peripheral blood. Japanese Journal of Clinical Hematology, 42(5): 414-419, May 2001).

Image text directs the observer to identify the inclusion(s) within the cell, thereby ruling out responses like segmented neutrophil (code:09), smudge cell (code:17), stain precipitate (code:50) or platelet satellitosis (code:53) as appropriate choices.

As an inclusion, the arrowed platelet is too small to be classified as a giant platelet (code:52).

Döhle bodies (code:21) represent residual aggregates of rough endoplasmic reticulum and are pale blue inclusions usually located near the cytoplasmic membrane and without the azurophilic granules seen within the gray-blue cytoplasm of the arrowed platelet.

The presence of yeast-fungi (code:55) or bacteria (code:50) in peripheral blood would be an important observation. On Wright's stained blood smears, these organisms would be more similar in appearance and color to the purple or dark blue granules seen with toxic granulation. Usually few in number, phagocytized fungi are enclosed within lysosomal vacuoles - creating a visible clear zone around the fungus.

Parasites (code:54) in the peripheral blood are usually seen within the red cells or as extracellular organisms. Malarial parasites are always located within the red cell. Extra-erythrocytic merozoites of a Babesia species would be similar in color to a platelet, but much smaller in size.

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