Re: monoclonal B-cells due to amyloidosis

From: Ierachmiel Daskal (DASKALI@einstein.edu)
Date: Mon Apr 29 2002 - 08:13:22 EST


This is an interesting case for many reasons. The diagnosis of Amyloidosis as it was
nicely pointed out by others must be rendered in a multi disciplinary fashion, namely a
combination of clinical, morphological, and Flowcytometric data ( when applicable). The
lymph node biopsy probably is crucial at this point since specific staining (
Congo Red, kappa /Lambda etc.) are crucial.  Also, electron microscopic studies if
warranted on the excised node are important and can nail the diagnosis immediately.
But more importantly there are clinical findings which will assist greatly in making
this diagnosis. So talk with your clinicians and get more historey on this patient.
The reversal of Kappa/Lambda that you got ,is significant inasmuch as it shows
the evolution of a light chain restriction but not necessarily a malignant process
yet. I have seen monoclonality in other disorders such as MGUS and massive infection
( hepatitis), and even autoimmune disorders. One must be cautious when finding an
isolated monoclonality without any other clinical findings.
The advice you got concerning the signing out of the case from Dr. Steller at the NIH
is sound, and is exactly the way we sign out such case.
Good luck.



Ierachmiel Daskal M.D. PhD. FCAP, FASCP
Chairman
Department of Pathology and Laboratory Medicine
(215) 456-6126
Pager: 2-3559
daskali@einstein.edu

>>> "Andrea Illingworth" <dcdsflow@mint.net> 04/24/02 02:45PM >>>
Dear group, once again I need your help!

We recently had a case (left cervical lymph node) which showed a mixture of 55% T-cells
(predominance of CD4) and 45% B-cells. The B-cells were CD19+, CD20+, CD22+, CD10-,
CD5-, CD56-, CD38 weak+ with 15% expressing kappa and 32% expressing bimodal lambda
(abnormal cells appear brighter positive for lambda). The patient had similar flow
findings (reported as suspicious for LPD/B) about a year with no evidence of lymphoma
by surgical pathology. It was sent out to a consultant who interpreted the reversed
kappa/lambda findings as due to amyloidosis.
I have done some "light" reading on this subject and am still not quite sure how
to report the flow findings. If I understand it correctly, in primary amyloidosis
(the only one associated with plasma cell dyscrasias) the amyloid is derived from
all or a part of a monoclonal Ig light chain. 20% of patients with amyloidosis have
multiple myeloma, the remaining patients have increased clonal plasma cells but they
don't reach 10% in the bone marrow which is required for a dx of MM.
My questions are:
1. What exactly does the reversed kappa lambda ratio mean in our case? That there are
monoclonal B-cells somewhere in this patient's body (?MM), producing the amyloid but
since these abnormal cells are not seen in this particular tissue, we can't call it a
LPD/B? In other words, if we find a monoclonal B-cell population, do we need to check
for amyloid first?
2. Can you see a reversed kappa/lambda ratio in cases other than primary amyloidosis
(secondary and familial)? I know some people might challenge me on the ratio still
being within the normal range but looking at the histograms, it looks restricted
(bimodal expression).
3. How do we report this out?

Your help is much appreciated

Andrea Illingworth, MS, H(ASCP)
Dahl-Chase Flow Cytometry
333 State Street
Bangor, Maine 04401



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