MyMyelomaTeam

That's a really interesting observation, and your instinct about plasma cell distribution is spot on. Bone marrow biopsies are taken from a single site — usually the hip bone — and plasma cells don't spread evenly throughout the marrow. Think of it like taking two soil samples from different spots in a garden; you might get Show Full Answer

That's a really interesting observation, and your instinct about plasma cell distribution is spot on. Bone marrow biopsies are taken from a single site — usually the hip bone — and plasma cells don't spread evenly throughout the marrow. Think of it like taking two soil samples from different spots in a garden; you might get very different results each time. This sampling variability is a well-recognized limitation of bone marrow biopsies. The percentage of plasma cells found can differ depending on:

- Where exactly the needle was inserted
- How large the sample was
- The lab technique used to analyze it
- Natural fluctuation in plasma cell activity over time So a drop from 20% to 15% without treatment doesn't necessarily mean your myeloma improved — it may simply reflect that the second biopsy sampled a slightly different area with fewer plasma cells concentrated there.

This is actually one reason why doctors sometimes use additional tests alongside biopsies, such as MRI or PET-CT scans, to get a broader picture of what's happening throughout the bone marrow.

It's absolutely worth raising this question with your care team before the trial, as understanding your baseline accurately is really important.

 AI-generated responses are not a substitute for medical advice. These services are not intended to diagnose, treat, or cure any condition or disease. Always ask your doctor about specific health concerns.

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