Its diagnoses must meet all four of the following criteria: biopsy-proven tumor consisting of clonal plasma cells; no evidence of any other plasmacytomas based on bone survey and MRI (or in place of MRI, CT scan); normal bone marrow examination; and absence end organ damage, CRAB features, or other signs or symptoms of systemic disease attributable to a plasma cell dyscrasia. Blood or urine myeloma proteins are usually undetectable or low in solitary plasmacytomas. Solitary plasmacytoma is a rare disease with an incidence in the USA of <450 cases per year. In a review of 1,691 cases in the US, the median age at diagnosis was 63 with males representing ~60% of all cases. The most common site of plasmacytoma involvement was bone (~58%) followed by upper or lower airway tract (~16%), soft tissue or connective tissue (~5%), central nervous system (~3%), gastrointestinal tract (~3%), skin (~1%), and all other sites (~3%). Overall median survival was 8.12 years with survival decreasing with age from 12.4 years for patients <40 to 5.2 years for patients of 60 years or older. Risk of its recurrence or progression to overt multiple myeloma within 3 years is ~10%.A subset of solitary plasmacytomas, termed solitary plasmacytoma with minimal bone marrow involvement, has the same criteria for diagnosis as solitary plasmacytoma except that bone marrow examination shows an increase in plasma cells from a normal value of ~0% to 1.5% to >~1.6% but less than 10% of total nucleated cells.
multiple myeloma, Waldenström macroglobulinemia, or other B cell-associated neoplasm, that has developed, often in a stepwise manner, from their MGUS precursors.The clinical importance of understanding this spectrum of diseases is that it can be used to: a) advise individuals on the likelihood of their condition progressing to a malignant phase; b) monitor individuals for the many complications that may occur at any stage of the dyscrasias so that they can be treated to avoid or reduce their clinical impacts; and c) monitor patients for transitions to malignancy so that the malignancy can be treated at an early stage when treatment results are best. Unless otherwise noted, the advice and monitoring given here are those recommended by the International Myeloma Working Group in 2014 and updated in 2016. Clonal plasma cells
Plasma cells are key effector elements of the adaptive immune system. They contribute to immunity by making antibodies that bind with and thereby initiate the process of neutralizing specific antigens that usually are found on the surface of invading pathogens and foreign substances. Plasma cells develop from B lymphocytes (i.e. B cells) which are stimulated to undergo this maturational development by T lymphocytes during the latter cells processing of these antigens. As they are stimulated to become plasma cells, B cells refashion parts of their genome in efforts to create a new gene that encodes a functional antibody.