I'll jump back into this.
I would make a diagnosis of CD5+ SLVL or CD5+ follicular lymphoma if I
had other studies (particularly morphology) to support the diagnosis,
but I would not make the diagnosis based solely on flow or on flow and
FNA cytology only.
I agree with Randy that many cases of HCL-variant are probably splenic
marginal zone lymphomas, but some are not. I have seen rare cases
with features of HCL-v with splenectomy specimens that do not have the
morphologic feature of splenic marginal zone lymphoma. They had the
expected red pulp pattern of infiltration without white pulp
involvement.
Dan Arber
____________________Reply Separator____________________
Subject: Re: CD5+ SLVL
Author: Maryalice Stetler-Stevenson <stetler@box-s.nih.gov>
Date: 08/04/2000 3:10 PM
So Randy, you would never diagnose a CD5+ case as SLVL? Even if
it is cyclin D1 negative and no lymph node involvement or bone
marrow involvement- only spleen and blood? As for forcing it
into HCL- what if the cells are also negative for CD25, CD103
and only dim CD11c?
To expand further- What about CD5+ follicular lymphoma?
This is getting to be a great discussion.
Maryalice
Hi Gang...I never use this forum, but can't resist this one.
I also agree with Dan Arber. The response he recieved about
the 1994 Blood paper is misleading. At that time, the
so-called SLVL collection in London had about 30% cases with
t(11;14). We all know what these are!! Peter Isaacson told
all of us at a meeting many years ago, related to his Blood
paper on the histopathology of SLVL, that virtually all of
these cases were MCLs. Thus, CD5 positivity in SLVL is
likely impossible to interpret from the published
literature. However, he also claimed to see CD5 infrequently
and discussed in that paper the distinctions between PB flow
and frozen-section Ipox. He also made note of variable
phenotypes as cells move from one compartment to another!
My best guess is that SLVL/HCL-variant etc is likely to be
one of several choices. Most are likely MZLs of different
types. We now know about CD5+ MALT lymphomas with a tendency
to involve BM and likely blood as well (AJCP paper with
Nancy Harris). Remember that Bill Pugh presented a small
number of cases at US&CAP many years ago (before the Harris
paper). If one looks at the cytogenetic data from the
literature, it gets even more interesting. I came across
several papers about HCL, HCL-variant etc, some of which had
isolated del 7q31-32. This cytogenetic finding is almost
certainly tightly connected to primary splenic marginal
zone. I would guess that classical cytogenetics and/or other
PCR-based approaches (how about taking such cases and
CD5-negative ones and doing RT-PCR for the AP12-MLT
rearrangement), together with gene expression data will
likely help to clarify much of the confusion in the
literature. Otherwise, this will continue to be a problem
area because of the vagaries of PB morphology/interpretation
and the reliance of so-called "signature" phenotypes.
Moreover, PB morphology cannot be equated in anyway with
histology in most of these cases. Are people surprized to
know that MCL (Bcl-1 proven) are CD5-negative in 3% of
cases!!
Randy Gascoyne
Randy D. Gascoyne
Department of Pathology
British Columbia Cancer Agency
600 W 10th Avenue
Vancouver, BC
Canada V5Z 4E6
Phone: (604) 877-6098, local # 2097
Fax: (604) 877-6178
E-mail: rgascoyn@bccancer.bc.ca
Maryalice Stetler-Stevenson
Director Flow Cytometry Unit
Laboratory of Pathology, NCI, NIH
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