Hello, I was diagnosed with an almost 9cm solitary plasmacytoma on my sacrum in Oct 2025. I had an M-spike upon diagnosis which they said was due to the tumor being secretory. Bone marrow biopsy was clear. I was given 25 rounds of radiation to cure it, but the tumor has not responded (shrunk) at all. M-spike has come down roughly 50%. I'm in terrible pain all the time from this tumor. Does anyone have experience with something like this? I keep asking about a surgical solution, but they are saying chemo would be the next step. I would like to avoid chemo since it is a localized problem. Any advice is welcome. Also has anyone had one surgically removed?