This study includes the use of Idelalisib to treat previously treated patients with IgM-associated AL Amyloidosis at Boston Medical Center. Boston Medical Center is internationally recognized as a leader in amyloidosis research and patient care through the activities of the multidisciplinary Amyloid Center at Boston University. The problematic cell in most forms of AL amyloidosis shares similarities with multiple myeloma. However, in the small subset of AL Amyloidosis patients with an IgM paraprotein, the cells are more typically related to lymphoplasmacytic lymphoma or Waldenstrom's macroglobulinemia. Because clonal cluster of differentiation antigen 20 (CD20)+ lymphoplasmacytic cells are usually responsible for IgM paraproteins, treatment paradigms based on Waldenstrom's macroglobulinemia (WM) may be more appropriate than myeloma-based strategies. Idelalisib has been shown to be active and well tolerated in patients with relapsed/refractory non-Hodgkin lymphoma including chronic lymphocytic lymphoma, and lymphoplasmacytic lymphoma with or without Waldenström's macroglobulinemia (WM). The side effect profile of idelalisib merges well with the known predisposition to toxicity of amyloidosis patient.