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Re: Elevated lambda free light chain level - meaning?

by JimNY on Wed Jul 13, 2016 1:19 pm

Wouldn't this finding in the aspirate report – "Plasma cells 4 %" – indicate that the bone marrow plasma cell percentage is 4%?

Also, if that's the case, isn't the most the clonal plasma cell percentage could be also 4 percent?

If no clonal (myeloma, cancerous) plasma cells are found in the bone marrow, but the lesion is found to be cancerous, then this would be a case of a solitary (bone) plasmacytoma.

If the lesion is cancerous and there are, in fact, some clonal plasma cells in the bone marrow, but the clonal plasma cell percentage is less than 10%, then the diagnosis would be "solitary plasmacytoma with minimal marrow involvement" according to the 2014 International Myeloma Working Group (IMWG) myeloma-related diagnostic criteria.

JimNY

Re: Elevated lambda free light chain level - meaning?

by Multibilly on Wed Jul 13, 2016 2:43 pm

Jim,

I actually thought the same thing regarding the bone marrow plasma cell percentage at first blush. But then I remembered your earlier post on the topic of bone marrow plasma cell percentages and how the IMWG now interprets those figures.

I lifted the diagnosis of a solitary plasmacytoma + MGUS from the Myeloma Beacon article I mentioned above:

"If the patient has less than 10 percent of abnormal plasma cells in the bone marrow, he or she is diagnosed with solitary bone plasmacytoma plus monoclonal gammopathy of undetermined significance, a common myeloma precursor disease".

But the IMWG definition also clearly works. I think you would agree that the important thing is the "solitary plasmacytoma" descriptor.

Multibilly
Name: Multibilly
Who do you know with myeloma?: Me
When were you/they diagnosed?: Smoldering, Nov, 2012

Re: Elevated lambda free light chain level - meaning?

by JimNY on Wed Jul 13, 2016 9:51 pm

Hi Multibilly,

I think I mis­under­stood what you were saying earlier. I thought you were saying that there was no information at all in the biopsy reports that would give an indication what the clonal plasma cell percentage might be. I get the sense now that you're just saying we can't be certain because we don't know what the plasma cell percentage is from the trephine biopsy.

Do you agree that the 4% estimate from the aspirate sample means that, in the aspirate, the clonal plasma cell percentage is no more than 4%?

I guess my question is: Can we assume that

Plasma cell percentage = healthy plasma cell percentage + clonal plasma cell percentage ?

At first glance, it looks like there isn't any information about the plasma cell percentage in the trephine sample. However, note this statement:

"There is a small excess of CD138 positive cells expressing lambda light chains."

To me, this is a subjective statement that there are minor signs of monoclonal plasma cells in the trephine sample, but minor enough that they were not quantified.

I think that, overall, indications are the clonal plasma cell percentage is low.

But what do you think?

JimNY

Re: Elevated lambda free light chain level - meaning?

by Multibilly on Wed Jul 13, 2016 11:11 pm

Jim,

I'm not 100% certain, but I was already thinking that your above statements are correct. But I was thrown by the diagnosis of smoldering multiple myeloma if the BMPC is indeed 4% or lower. I'm not sure why a doctor would offer up that diagnosis of smoldering multiple myeloma given a BMPC of <= 4% and an M-spike < 30 g/L. Take care.

Zodiaccatznz,

Sorry for the little side discussion. In any case, I will again say that it will be key to understand from your doctor just what your clonal bone marrow plasma cell percentage is, as well as the details about your lesion, and why he/she thinks you have a diagnosis of smoldering multiple myeloma.

Note that with the many new modern treatments available for multiple myeloma in just the past few years, many folks on this forum respond very well to treatment. So, don't despair.

Also, note that if your lesion ends up being benign or not a lesion at all (which is the situation that happened to me when I was first diagnosed), you could very well end up with a diagnosis of MGUS. Most people with MGUS go through life none the worse for having the condition and never know they have it.

Good luck with all this and let us know how the next steps go.

Multibilly
Name: Multibilly
Who do you know with myeloma?: Me
When were you/they diagnosed?: Smoldering, Nov, 2012

Re: Elevated lambda free light chain level - meaning?

by JimNY on Thu Jul 14, 2016 10:50 am

Multibilly,

Good point. The smoldering diagnosis does make you wonder if there are results other than those listed above suggesting that the bone marrow plasma cell percentage is higher than 10 percent.

My guess is that the diagnosis is still up in the air at this point. Smoldering would not fit at all, for example, with a lesion having been found -- even if the cause of the lesion is still uncertain. So I wonder if Zodiaccatznz's doctors are just putting out "placeholder" diagnoses that are roughly correct, but not precisely.

JimNY

Re: Elevated lambda free light chain level - meaning?

by Zodiaccatznz on Sun Jul 17, 2016 8:30 am

Hello all

This is copied from the specialist's letter. I believe it's the trephine that is the higher one ?

Investigations:

Haemoglobin 140 g/L, white cells 6.3, neutrophils 3.3, platelets 296 x 109/L, creatinine 77, eGFR 86, corrected calcium 2.3, albumin 41, β2 microglobulin pending, CRP <3, LFTs normal
IgG 11.8, IgA 1.4, IgM 0.,8 g/L, serum free light chains as follows: kappa 12.3, lambda 172.00, kappa to lambda ratio 0.05

Bone marrow aspirate showed normal haematopoiesis with 4% plasma cells (in itself not diagnostic of myeloma)

Bone marrow trephine with immunophenotyping showed normal cellularity and haemato­poiesis but with plasma cell load of about 10% consistent with a diagnosis of myeloma

Myeloma FISH panel negative for t(4;14) translocation and negative for p53 deletion/mutation

CT skeletal survey (05.07.16) focal area of decreased bone density with some heterogeneity noted in the left ileum at the sacroiliac joint level maximum diameter approximately 35 multiple myeloma – differential diagnosis includes plasmacytoma but also other pathology such as fibrous dysplasia

Investigations pending:
Abdominal fat pad aspiration (?amyloid)
Echocardiogram
Further imaging of pelvic lesion – possibly MRI or PET CT scan – depending on results of MDM discussion tomorrow

Does any of this make more sense ? Thanks

Zodiaccatznz
Name: Catlovernz

Re: Elevated lambda free light chain level - meaning?

by Multibilly on Mon Jul 18, 2016 7:55 pm

The trephine is the tool they use to take out a core sample of your bone. So, the marrow trephine would likely refer to your "core sample". They also suck some of your bone marrow fluid out during this procedure. That is referred to as your "aspirate".

In general, doctors will measure plasma cell percentages in both the core sample and the aspirate. If there is a difference in the bone marrow plasma cell percentages between the core and the aspirate samples, then you generally go with the higher reading for diagnostic pur­poses. But you should also read Dr. Voorhees' comments on this subject for some important caveats.

It would also make sense to follow up with an MRI or PET/CT to get to the bottom of the CT dif­fer­ential diagnosis of a possible plasmacytoma.

Let us know what you find out and good luck.

Multibilly
Name: Multibilly
Who do you know with myeloma?: Me
When were you/they diagnosed?: Smoldering, Nov, 2012

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