Re: Unusual acute leukemia

Anna Porwit-MacDonald (anpo@mb.ks.se)
Mon, 3 Mar 1997 08:57:11 +0100

>Hi,
I have seen a couple of B-precursor ALL cases with very weak (could be
interpreted as negative) CD19 positivity and positivity for CD10/TdT.
In these cases the cyt. CD22 and/or cyt.CD79 were positive (stained with
APAAP method on cytospins) proving the B lineage.
Your case might be similar to those.
Best wishes
Anna Porwit-MacDonald MD, PhD
Haematopathology Lab,
Karolinska Hospital, Stockholm

>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
>negative/non-specific.
>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
>phenotype.
>
>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
>(207)990-4855
>
>
>