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OK @b_d4512 it’s myeloma time!!
First of all as I’ve already alluded to all malignancies have a cell of origin. The cell that has developed a series mutations to allow it to become cancerous. And in myeloma it’s the plasma cell, the one that makes antibodies (except usually IgM)
First of all as I’ve already alluded to all malignancies have a cell of origin. The cell that has developed a series mutations to allow it to become cancerous. And in myeloma it’s the plasma cell, the one that makes antibodies (except usually IgM)
The problems that neoplastic plasma cells cause depends on how many of them there are, where they are and what they are doing
They usually retain some characteristics of normal plasma cells eg antibody production, but because they are derived from a single cell the antibody is all the same ie monoclonal rather than lots of different ones - polyclonal
If there’s a few neoplastic plasma cells with lots of normal ones, no end organ damage, and a paraprotein by definition <30g/L (usually <10-15) then it’s MGUS, monoclonal gammopathy of uncertain significance, and that gets watched as it can progress to myeloma
If there are lots of plasma cells in the marrow (10-60%) or the paraprotein is over 30 then it’s asymptomatic myeloma which gets watched closely
If the plasma cells are in a lump, and not throughout the marrow, that is a solitary plasmacytoma (if one: can be treated with radiotherapy), if lots of lumps it’s multiple plasmacytomas (need chemo)
And if the plasma cells are causing problems then it is myeloma. We diagnose on bone marrow biopsy and plasma cells are sneaky and can get a bit stuck so you don’t often have huge percentages of cells and you need other clinical information to decide what to do
Anyway what problems do these myeloma cells cause? Symptomatic myeloma is defined by presence of one or more of the CRAB criteria
• hyperCalcaemia
• Renal impairment
• Anaemia
• Bone involvement (so we do a low dose CT to look at all the bones for lytic lesions)
• hyperCalcaemia
• Renal impairment
• Anaemia
• Bone involvement (so we do a low dose CT to look at all the bones for lytic lesions)
Myeloma tends to be slowly growing hence like eg follicular lymphoma in general it can’t be cured and treatments are given when it’s symptomatic to control and hopefully get the patient into remission
That’s probably enough for now!! But please ask anything 
