Lymphoma - B cell neoplasms
Plasma cell neoplasms
Monoclonal gammopathy of undetermined significance (MGUS)
Reviewer: Nikhil Sangle, M.D., University of Utah and ARUP Laboratories (see Reviewers page)
Revised: 13 March 2011, last major update March 2011
Copyright: (c) 2001-2011, PathologyOutlines.com, Inc.
● Monoclonal immunoglobulin in serum or urine without clinical features of multiple myeloma or macroglobulinemia
● By definition, no evidence of other B-cell lymphoproliferative disorder
● More common than multiple myeloma (1 million vs. 13,000 cases/year in US)
● Higher prevalence in African-Americans
● Incidence increases with age (mean age 64 years): 1% of healthy people age 50+ years vs. 3% at 70+ years
● Paraprotein is usually discovered unexpectedly: 70% IgG, 15% IgM, 12% IgA, 3% biclonal; monoclonal light chain in urine in 1/3
● Serum immunoglobulin level less than 3g/dl
● No myeloma-related organ or tissue impairement (no CRAB features related to myeloma: hypercalcemia, renal insufficiency, anemia, bone lesions)
● Follow with serial measurements of monoclonal protein but usually no specific treatment
● Risk of progression to overt myeloma is 1% per year; can evolve to myeloma, amyloidosis, Waldenstrom’s macroglobulinemia or other lymphoproliferative disorder
● In one study, 26% progressed to overt malignant plasma cell disorder over median of 10 years
● <10% clonal plasma cells in bone marrow
● Plasma cells lack nucleoli (Am J Clin Pathol 2001;115:127)
End of Lymphoma - B cell neoplasms > Plasma cell neoplasms > Monoclonal gammopathy of undetermined significance (MGUS)
This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.
All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at [email protected] with any questions (click here for other contact information).