Plasmacytoid lymphoma is associated with (AIPG 2010)
IgM (Ref. Hari- 18th ed., Pg. 938)
1. A malignancy of lymphoplasmacytoid cells that secreted IgM. In contrast to myeloma, the disease was associated
2. with lymphadenopathy and hepatosplenomegaly, but the major clinical manifestation was the hyperviscosity syndrome.
3. The disease resembles the related diseases chronic lymphocytic leukemia, myeloma, and lymphocytic lymphoma. It originates from a post–germinal center B cell that has undergone somatic mutations and antigenic selection in the lymphoid follicle and has the characteristics of an IgM-bearing memory B cell.
4. Waldenström's macroglobulinemia and IgM myeloma follow a similar clinical course, but therapeutic options are different.
5. The diagnosis of IgM myeloma is usually reserved for patients with lytic bone lesions and predominant infiltration with CD138+ plasma cells in the bone marrow.
6. Such patients are at greater risk of pathologic fractures than patients with Waldenström's macroglobulinemia.
7. IgM in some patients with macroglobulinemia may have specificity for myelin-associated glycoprotein (MAG), a protein that has been associated with demyelinating disease of the peripheral nervous system and may be lost earlier and to a greater extent than the better known myelin basic protein in patients with multiple sclerosis.