[goldmine848]

How high does M Spike need to be for FISH testing?

by goldmine848 on Mon Aug 25, 2014 10:02 am

This may seem like an odd question, but here is why I ask. I have been unable to get FISH cyctogenetic results because my first BMB was a dry tap and the next two yielded no myeloma cells to test. My M Spike is now 0.4 and I am wondering what is the likelihood that a BMB will yield sufficient myeloma cells for FISH testing.

[Dr. Jatin Shah]

Re: How high does M Spike need to be for FISH testing?

by Dr. Jatin Shah on Mon Aug 25, 2014 8:06 pm

The level of M spike does not necessarily correlate with the ability to do FISH testing, as some patients may have oligosecretory or non-secretory myeloma.

The low level of your M spike would suggest a low tumor burden and, remember, the disease can be very patchy in distribution throughout the bone marrow space. Therefore, it is not entirely surprising there would be no plasma cells in the bone marrow biopsy.

In general, it does not take many cells (200-500 cells) to do FISH studies and therefore if there is any increase in the number of cells, there should be enough to do FISH studies.