For all of those involved in clinical flow labs, particularly those
receiving specimens from a variety of locations and practice types, I was
wondering how you handle specimens received where flow cytometry isn't
particularly necessarily indicated and/or justified. Specimens such as "Bone
marrow, rule out MDS", "Lymphoma staging, history of Hodgkin lymphoma",
"Monoclonal gammopathy, rule out MGUS versus other", or Leukocytosis,
probable CML. In my setting, I have the luxury of having the clinicians send
a specimen for flow on every bone marrow, and deciding whether or not to run
it based on the history and review of a slide prepared from the flow
specimen (smear and/or cytospin). This is particularly helpful for the
unsuspected CML in blast crisis or the patient with Hodgkin lymphoma that
has developed an unsuspected therapy-related acute leukemia. In many cases
there is no reason to run the flow and I just inform the clinician that I
decided not to run the flow in this particular case. However, I know this
scenario is not always practical or efficient, particularly in a high volume
and/or reference setting. I also realize that this is lab dependent and
varies with the experience that each has with any particular disorder (there
is a broad spectrum about how individuals and labs view the role of flow for
certain diagnoses such as MDS and plasma cell dyscrasias). In addition,
there are many instances where tissue is obtained during a surgical
procedure (lymph node, extranodal mass, etc.) and a fresh specimen is sent
directly to the flow lab, particularly if it has to be FED-EXed and will not
arrive until the following day. When slides are reviewed the following day
by the submitting institution (often at about the time your lab may receive
the flow specimen) and/or cytospins are prepared from the flow specimen, it
sometimes becomes clear that the process is reactive, non-hematopoietic,
etc. Given that:
1. Do most labs routinely make a slide preparation from the flow cytometry
specimen? If so, do you tailor your panel based on morphology and history or
do you have
standard prepared panels that are run on all specimens?
2. If an abnormal population is not identified on slide review (no
significant blasts, atypical lymphocytes, plasma cells, etc.), is a limited
panel still performed or does the
analysis stop here without performing flow (assuming that this is the
original diagnosis and that you are not looking for minimal residual disease
of a known diagnosis)?
3. Do you routinely perform flow for plasma cell dyscrasias, particularly if
only a small percentage (< 10%) is seen on slide review?
4. If a slide is not prepared, do you run certain panels based on a
suspected diagnosis (i.e, myeloid/blast markers on possible MDS; CD38,
CD138, cytoplasmic light chains
for monoclonal gammopathy, etc.)?
5. If review of a lymph node/extranodal mass (cytospin or H&E-stained
slides) shows a reactive process, non-hematopietic tumor (metastatic
carcinoma), possible Hodgkin
lymphoma or anaplastic large cell lymphoma, is flow still run?
I realize there are no real right or wrong answers to these questions, but
have been pondering them for a while as my short career has evolved from a
fellow, to director of a mid-sized military lab, and shortly to private
practice to run a small clinical flow cytometry service. Thanks in advance
for your insights, advice, and experience with these questions.
Sincerely,
Christopher S. Bee, M.D.
Medical Director, Flow Cytometry
Wilford Hall Medical Center
San Antonio, TX
(210) 292-5455
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