What is macro focal myeloma? How is it diagnosed? How is it treated?

What is macrofocal myeloma?

So macrofocal myeloma is another very undefined area. The imaging modalities that we started doing, like the MRIs and the PET scan started to find a disease pattern that has not been defined before, which is a patient that have very few plasma cells in the bone marrow or no plasma cells in the bone marrow and tumors scattered throughout the skeleton, usually form of plasma cells, what's called plasmacytoma. They are usually more than one, and that's why it's called multifocal. If it's only one, it's called solitary plasmacytoma. That's a completely different entity. But the multifocal plasmacytoma is scattered lesions of tumors throughout the skeletal image of plasma cells. They usually don't secrete a lot of protein, and they are actually quite difficult to diagnose. And these are present with pain and fractures. And then you do a biopsy, you find the plasma cells. Most of those patients present with pain, and usually it's diagnosed with younger patients. So especially in newly diagnosed patients, usually younger patients. So especially in newly diagnosed patients, usually younger patients. And the outcome of those patients is quite good. We treat them with systemic treatment, we give them systemic treatment and stem cell transplant if they meet the criteria for that followed by maintenance, and they have excellent outcome, that's when it occurs upfront or newly diagnosed. The multifocal plasmacytoma that occurs later on in the disease is a little bit of a different entity and it is being seen more nowadays. So we see a lot of this multifocal relapses occurring in myeloma with bone marrow showing no plasma cells, but tumors popping up usually in the shoulders or back. And this particular entity is being seen nowadays an immune therapy. So a patient that have allogeneic transplant, for example, when they relapse, their bone marrow is completely taken over by the donor cells and the relapse occurs outside of the bone marrow. And those multifocal sites, they're seeing some of the CAR-T cell trials, most of the CAR-T cell trials clean up the bone marrow. Very quickly, you have what's called MRD negativity. The bone marrow is clean, but you still have some of those focal areas. In general, the multifocal plasmacytoma that occurs and relapses setting do have a poor outcome and those patients do not do as well as also present upfront with multifocal plasmacytoma. How is macrofocal myeloma treated? And relapse you try different things. You try any relapsed disease. If it's causing a lot of symptoms and diagnosis of relapse, then radiation might be indicated. Inflammation is not indicated in your systemic treatment and it follows the same paradigm you look for any relapse myeloma. In general, normal plasma cells secrete more or less the same amount of heavy chain and light chain. And that's how you have the immunoglobulin molecule when you disease starts progressing, you saw more light chains and that's how you pick up the vengeance protein and the urine or the free light chain of the serum. As a disease becomes more aggressive, some of those cells stop making light chains and heavy chains and they become lymphoma like disease. And those patients form tumors. And this can be tumors in the soft tissue or in the bones. So that is really no clear distinction between what represents early myeloma versus late myeloma. This kind of plasmacytoma can be present in multiple stages of the disease.