This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Plasmacytoid lymphomas may be associated with 
Select and explain. 
A. IgG, B. IgM, C. IgA, D. IgE
B: IgM
Answer: B: IgM 
Explanation: Ans. is `b' i.e., IgM Plasmacytoid lymphoma Plasma cytoid lymphoma, also known as plasmacytoid lymphocyte type malignant lymphoma, is a B cell neoplasm that is associated with plasmacytoid differentiation of lymphocytes. Plasmacytoid lymphocytes are transitional forms between lymphocytes and plasma cells. o These are low grade lymphoid neoplasms that occur in middle aged or older individuals. o In REAL classification, it is classified as lymphoplasmacytic lymphoma. o These may be associated with a monoclonal IgM paraprotein and are thus considered the histological counterpa of Waldenstrom's macroglobulinemia.