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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