Dear Dr Mann:
This is my 1st time answering a question on the net. I usually just
read the chat. Over the years I have used CD103 and find that it is
expressed in all kinds of chronic B-cell leukemias, particularly the
CD11c only variety ( ie SLVL, marginal zone LPD, leukemic Maltomas
etc).. I would not make a diagnosis of HCL with TRAP negativity and
absent CD25 and 11c. I have seen several hundred cases of HCL over the
last 8-10 years, but none without CD11c and CD25. Most also express
CD103. However, CD103 is certainly not specific for HCL. I have found
CD103 expressed in a number of so-called HCL look- alikes. What about
monocytopenia and/ or BM histology. What do the cells in the PB look
like? HCL has a characteristic nuclear morphology.
The more difficult problem are the cases of CD11c only disease that
lack CD25, usually TRAP negative, but may express CD103. Are these
HCL-variants or something else?
Randy Gascoyne
Hematopathologist
=09
=09
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=BBFrom: Kees Pot
=BBTo: Randy Gascoyne
=BBSubject: FW: hairy cell leukemia
=BBDate: Tuesday, 31 December, 1996 9:21AM
=BB
=BB
=BB ----------
=BBFrom: mann0002@mc.duke.edu
=BBTo: Cytometry Mailing List
=BBSubject: hairy cell leukemia
=BBDate: Tuesday, December 31, 1996 6:36AM
=BB
=BB
=BBI received peripheral blood for immunophenotyping for a question of
hairy cell
=BBleukemia. (The patient is an elderly male with splenomegaly and
circulating
=BB"hairy cells".) There is bright expression of the pan B cell markers
CD19, CD20
=BBand CD22 as well as lambda light chain. The cells are negative for =
CD5
and CD10.
=BBAlthough there is expression of CD103, the cells are negative for =
CD11c
and
=BBCD25. The cells are reportedly TRAP negative.
=BB
=BBI know that some people consider staining for CD103 highly specific =
for
hairy
=BBcells, but the absence of CD11c is very worrisome to me. What other B
cell
=BBneoplasms have you found to be CD103 positive? Would anyone consider =
a
=BBdiagnosis of hairy cell leukemia in the absence of staining for =
CD11c.
=BB
=BBKaren Mann
=BB