Click for higher resolution image.

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

Slide 136 [100X]        Click here for a higher resolution image.

433 laboratories correctly identified this cell as a monocyte (Code:12). The nucleus is indented with slightly clumped chromatin. The cytoplasm is gray-blue with pink azurophilic granules and contains numerous empty vacuoles.

Monoblasts (code:04) are associated with conditions in which there is marked proliferation of cells of the monocytic type, as in monocytic leukemia. With Wright's stain, these cells have fine and distinct nuclear chromatin, visible nucleoli and agranular cytoplasm.

Monocytes can be difficult to differentiate from other cells. Because of their variable shape and morphology, monocytes can be confused with neutrophils or large lymphocytes. Lymphocytes responding to antigenic stimulation become large and may contain azurophilic granules and vacuoles. The extent of vacuolization and granulation distinguish this cell from an atypical or reactive lymphocyte (code:11)

Number of Responses Percent of Laboratories Cell Code and Type

433

98.0

Code  12: Monocyte

4

0.9

Code  04: Monoblast

3

0.7

Code  11: Atypical lymphocyte

1

0.2

Code  01: Blast cell, not classified

1

0.1

Code  06: Myelocyte

Return to January 2002 Proficiency Test Event