Unusual acute leukemia

Thu Feb 27 16:27:21 EST 1997

To all clinical flow people,

We have had an unusual case of an 0acute leukemia which I would like to
share with you, hoping you have seen something like this before and can
explain our flow findings.

This is a 7 year old female with the following CBC findings:
WBC: 15.3
RBC: 3.26
Hgb: 9.5
Plt: 26,000
blasts: 16%

Cytochemistry: negative for myeloperoxidase
The CSF showed also leukemic infiltrate.

Review of the marrow aspirate shows a predominance of blasts.  The blasts
range in size from small to large with occasionally prominent nucleoli and
generally scant cytoplasm.  No Auer rods are identified.

Flow cytometric analysis showed the blasts to have both increased FALS and
SS and to be positive for CD45 (weak to moderate), CD10 (weak to moderate),
and TdT.  CD19 was negative!! The blasts were also negative for CD2, CD5,
CD7, CD13, CD15, CD33, CD11c, and CD34.  There was some weak positivity for
CD20 and cytoplasmic IgM which I am inclined to interpret as
DNA content analysis showed a near tetraploid/DNA aneuploid population with
a DNA Index of 1.95.

This case was signed out as acute lymphoid leukemia with undifferentiated

We were really puzzled by the absence of CD19 as well as by the high DNA
Index in a B-ALL.  Also, aren't undifferentiated ALL's usually CD45 negative?

If you have ever encountered a case like this, we would greatly appreciate
your input! 
Andrea Illingworth
Dahl-Chase Diagnostic Services/Flow Cytometry
333 State Street
Bangor, Maine 04401

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