Ken,
I would disagree with the idea that most people are moving from morphologic to
purely immunologic and genetic classification of lymphomas, but I would agree
that some posts in this group neglect the morphologic features of the tumors
being discussed. Modern classification of lymphoma combines all three of these
features, and in most cases the morphologic features fit very well with the
immunophenotype. We should remember that the early morphologic classification
systems did have clinical significance and should not be ignored. Adding these
other methods allows us to further define entities, but should not entirely
replace the significance of the morphologic features. When immunologic features
do not fit the morphologic features, I go back and review the morphology again.
That is not to say that I will re-classify any case purely on its
immunophenotype, but all of the available information should be put together to
make an accurate diagnosis. That is why I think the morphologic features, as
well as the pattern of bone marrow involvement were important elements of the
case that started this discussion.
Dan Arber
______________________________ Reply Separator _________________________________
Subject: Morphologic and Immunologic Terms for Lymphomas
Author: aultk.mmcwp4@mmc.org at INTERNET
Date: 1/8/97 9:46 AM
I have been "listening" to the discussion about the
confusion between terms like "follicular lymphoma" and
specific immunophenotypes with interest because this is a
topic of interest to me for many years. At the risk of
offending some of my good friends on this list I would like to
add my two cents to the discussion and maybe expand it
somewhat.
I think that we are all gratified that the continual evolution in
lymphoma classification has begun to utilize
immunophenotypic descriptions more and more - this is long
overdue. However, we must remember that all of the
historical classifications, especially those including such
terms as "follicular", "mantle", etc. are based on (highly
subjective in my view) morphology. We now seem to be in a
transition phase between morphologic descriptions and
immunophenotypic and genetic definitions of these diseases.
We are asking for a lot of confusion, and we are doing
ourselves a disservice, if we keep trying to align morphologic
descriptions with specific immunophenotypes.
In my view, it is especially unfortunate when we create new
disease entities based not upon clinical criteria but upon
variations in our own classification systems. For example:
is a CD10 positive follicular lymphoma a different disease
than CD10 negative follicular lymphoma? We shouldn't
mistake a failure of our multiple classification systems for
new diseases!
This may a lengthy restatement of the obvious, but I needed
to say it - and I feel better now!
Ken Ault
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