[Billy1]

Bone Marrow Biopsy Results

by Billy1 on Sun May 15, 2011 2:38 pm

Hello:
New poster here:

It seems that most Doctors when determining Plasma Cell Counts in bone marrow biobsy use the conventional Morphology (bone marrow aspirate) and Flow Cytometry to analyse there findings, and that this is the gold standard accepted by the Durie-Salmon staging system and the International Staging System. However I have read numerous pathology articles recently which questions the accuracy of certain findings using this criteria by itself.

Due to the fact that Myeloma Plasma Cells can be "patchy" depending where the biobsy was performed the articles state that for a much more accurate reading a CD138 Immunohistochemistry stain test should be conducted. It is startling in these articles how many patients are under counted by the conventional procedures for Plasma Cell Biobsy when tested again using the far more accurate CD138 staining tests. One article in the hematoligy journal states that the coefficient of variation in patients with MGUS ( less than 10%PC) has been demonstrated as high as 46% with the vast majority showing higher counts using CD138 staining.

The Question arises then that why isn't the CD138 staining test made mandatory by the various Staging Systems? I understand that some institutions use this as almost a standard procedure where others do not. It seems that the implications are clear. Some patients may be mis-diagnosed by the normal method (morphology) and would be unaware that a more accurate method (CD138) is not being conducted, leading to no treatment such as MGUS or the wrong treatment for multiple myeloma.

Hope Someone has some thoughts on this.
Regards to all.
Billy

[Dr. Edward Libby]

Re: Bone Marrow Biopsy Results

by Dr. Edward Libby on Mon May 16, 2011 8:56 pm

Hello !
That is a good question. The answer from my perspective is that there are MANY aspects to diagnosis that could be improved on. Just as important (probably more) as using CD138 is getting an adequate bone marrow biopsy sample. Many biopsies have little marrow actually in them because only cortical bone (the outside of bone) was sampled or the patient may have signficant pain during the procedure and so the biopsies are limited to decrease discomfort. Diagnosing myeloma is a process of putting together many different data points and no one result has all of the answers. Many/most laboratories do use the CD 138 stain though so in the big picture of things I think this is not a major issue.