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

Slide 139 [100X]        Click here for a higher resolution image.

Slide 139 was taken from a case of acute lymphoblastic anemia (ALL). The arrowed cell is a lymphoblast (code: 03). The cell is large with a high nucleus to cytoplasm ratio. The cytoplasm is deeply basophilic without visible granules. The chromatin strands are thin, evenly stained and reddish purple. Two nucleoli are visible. A marked heterogeneity in the size of these early cell types is evident. Because of the difficulties in distinguishing lymphoblasts from other types of blasts and without additional cytochemical stains or cell surface marker evidence, blast cell, not classified (code: 01) is an appropriate response for this challenge.

The presence of several other early lymphocytes in the image makes the selection of myeloblast (code:05) an unlikely choice.

Number of Responses Percent of Laboratories Cell Code and Type

401

90.7

Code 01:  Blast cell, not classified

33

7.5

Code 03:  Lymphoblast

5

1.1

Code 02:  Myeloblast 

2

0.5

Code 05:  Promyelocyte

1

0.2

Code 12:  Monocyte

Return to January 2002 Proficiency Test Event