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The bone marrow is a soft tissue that is inside some of
the larger bones. It contains stem cells which develop
into the three different types of blood cell: red blood cells white blood cells,
and platelets.
It's common to be diagnosed with lymphoma at an
advanced stage (III or IV) and with bone marrow involvement.
While this might seem alarming, you should know that advanced stages
of lymphoma can be treated successfully, and that lymphoma in the
bone marrow is as reversible as lymphoma anywhere in the body.
One way to understand this is to compare lymphoma
with a so-called solid tumor, such as a prostate cancer. Here
the cell of origin of the cancer does not normally exist anywhere
but in the prostate. So when you find malignant prostate cells
in the bone marrow, you have a serious problem. Compare with
blood cells that we expect to move anywhere in the lymphatic or
circulatory system, including the "nursery" for these
cells, the bone marrow.
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Bone marrow involvement and survival for low grade NHL?
PubMed
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articles
"Conclusion. The presence of bone marrow infiltration at
diagnosis did not significantly affect the prognosis of low grade non-Hodgkin's Lymphoma (LGNHL)."
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A diagnosis of lymphoma in the bone marrow can only be established by obtaining a bone marrow specimen for
analysis - a bone marrow biopsy.
This test might be done for staging purposes in order to provide a
baseline of where the lymphoma is so that it can be monitored for
progression, guide treatment, and judge response to subsequent
treatment. (Also see Some
Reasons for a Bone Marrow Biopsy.)
Is a negative [for lymphoma] bone marrow
finding conclusive?
A negative bone marrow result means that there's an improved chance that the marrow is clean or relatively clean, but it's not a conclusive result.
Here's an analogy: Take a bucket of water out of a swimming pool at night. If no leaves
are in the bucket you can't conclude the pool is without leaves - only that the sample
has no leaves.
Improving the sampling process
Imaging such as MRI or PET can "help increase the positive
yield of bone marrow biopsies by guiding the marrow sampling
procedures to sites of relatively hypercellular marrow." (Magnetic
Resonance Imaging of the Bone Marrow in Hematologic Malignancies
bloodjournal.org)
Bilateral testing (taking sample
from both sides) will be more reliable: (Bone marrow biopsy for the staging of non-Hodgkin's
lymphoma: bilateral or unilateral trephine biopsy?
Tumori. 1995 Nov-Dec;81(6):410-3. PMID:
8804465 | Related
articles)
Improving the sensitivity of the
bone marrow biopsy test?
NOTE: Lymphoma cells are very
very small. For example, a one centimeter tumor has about 1
billion lymphoma cells. So lymphoma cells will not be
detected by many standard tests unless there are a significant
number of cells to form a mass (a tumor) in the sample.
Returning to the analogy of testing
for leaves in a pool, a sample taken with a bucket that has no
leaves (tumors) might have small traces of leaf fragments
(individual tumor cells) that are not visible with plain sight,
which might be detected by other tests.
One very sensitive test for lymphoma cells is called PCR. It
can detect for the presence of genetic translocations (that are
unique to some kinds of lymphoma in the sample).
Bcl-2/ t(14;18)
Gene Rearrangement, Quantitative Real-Time PCR Questdiagnostics
"The t(14;18) translocation is characteristic of B-cell
lymphomas, occurring in up to 90% of follicular lymphomas.
It is also found in 20% to 30% of diffuse large B-cell lymphomas
..."
Also see: What is PCR Testing? questdiagnostics
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Successful response to Rituximab as a single
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