Diseases associated with a monoclonal (or myeloma) protein (M protein) included in this presentation are:

1. Asymptomatic plasma cell neoplasia with minimal evidence of disease aside from the presence of an M protein (monoclonal gammopathy of undetermined significance [MGUS]).[1] (Usually IgG kappa or lambda, IgA kappa or lambda.)



2. Symptomatic plasma cell neoplasia. (Usually IgG kappa or gamma, IgA kappa or gamma.)
   1. Primarily affecting bones:
      1. Multiple myeloma (94%).
      2. Solitary plasmacytoma (3%).
   2. Extramedullary plasmacytoma (3%).

      These usually occur in the nasopharynx, tonsils, or paranasal sinuses.[2]




3. Macroglobulinemia.

   Patients often have lymphadenopathy and hepatosplenomegaly; less than 5% of patients have lytic bone lesions. (Usually IgM kappa or gamma.)

   1. Asymptomatic.
   2. Symptomatic.[3]

   This entity is called lymphoplasmacytic lymphoma or Waldenström macroglobulinemia. (Refer to the PDQ summary on Adult Non Hodgkin Lymphoma Treatment ¹ for more information.)

References

1. Kyle RA, Bladé J, Rajkumar SV: Monoclonal gammopathies of undetermined significance. In: Malpas JS, Bergsagel DE, Kyle RA, et al.: Myeloma: Biology and Management. 3rd ed. Philadelphia, Pa: WB Saunders Co, 2004, pp 315-52. 
   
   
2. Knowling MA, Harwood AR, Bergsagel DE: Comparison of extramedullary plasmacytomas with solitary and multiple plasma cell tumors of bone. J Clin Oncol 1 (4): 255-62, 1983.  [PUBMED Abstract]
   
   
3. Kyle RA, Garton JP: The spectrum of IgM monoclonal gammopathy in 430 cases. Mayo Clin Proc 62 (8): 719-31, 1987.  [PUBMED Abstract]