Abnormal tetraploid clone?

I just got the full report from a bone marrow biopsy that was done last month at Mayo. There’s a new thing I’ve never seen before, so I’d like to know what your experiences are with this. Here’s the paragraph I’m concerned about:

INTERPRETATIONS
The result is abnormal and indicates a plasma cell clone with an IGH gene rearrangement and monosomy 13. In addition, approximately 50% of plasma cells had a tetraploid version of this clone. An abnormal tetraploid clone is reportedly associated with an unfavorable prognosis in multiple myeloma.
Reference: Fonseca et al., Blood 99:3735-3741, 2002.

I’m seeing Dr. Orlowski next week, and will ask about this, but I’m checking to see if anyone has personal experience with this, and can offer an explanation of what it means in layman’s terms.