[Skip13]

Plasma cells with lambda excess, but no clonality?

by Skip13 on Tue Jun 27, 2017 6:43 am

I've detailed my father's case in a separate thread. In short, he had a large extramedullary plasmacytoma on his left kidney. He had radiation and it shrank considerably, but a couple months later he had some bumps form on his back and a PET scan showed around ten new soft tissue plasmacytomas. He went on Kyprolis and Revlimid for a few months and then had an autologous transplant and has continued on just Revlimid for about a year now. All tests have been good up until now.

He has never had anything show up on any of his past bone marrow tests. His "Prot Electro­phoresis / Immunofixation" showed an IgA spike when he had the tumors, but has since been low and stayed low along with everything else, including light chains.

His PET scan which was done at the same time as his bone marrow was completely clean.

The results of the bone marrow state:

"Cellular marrow with trilineage hematopoiesis and 11% plasma cells with lambda excess but no convincing evidence of clonality via flow or IHC, see microscopic description."

That's the general pathology at the top. There is a lot more I'll add which I think may be relevant, but if anything else is needed, just ask.

"Flow cytometric analysis on the marrow aspirate using a panel of antibodies (CD20, CD3, CD19, CD38, CD45, CD138, KAPPA, LAMBDA, CD56 and CD117) was performed. After gating on plasma cells using CD38 vs CD138, plasma cells account for 0.47% of all cells. The plasma cells demonstrate significant lambda light chain excess without obvious clonality. See attached flow cytometry report for additional details.

Additional in situ hybridization stains for kappa and lambda immunoglobulin light chain show polytypic plasma cells accounting for 10-15% of marrow cells without evidence of light chain restriction."

If anyone can give any thoughts onto this is would be great. Doesn't seem to be the myeloma, but could Revlimid be causing this? Also, what could I look up to research this. Trying to find anything referring to lambda excess in bone marrow doesn't come up with much. It doesn't show clonality, so I assume it isn't any sort of cancer, but what could cause him to make extra lambda plasma cells in his bone marrow? The vaccinations he's been receiving even?

Note he does only have 1 kidney now and his light chains have been slowly raising since his stem cell transplant. However, the ratio in his blood has stayed in range the entire time.