. Author manuscript; available in PMC: 2024 Feb 1.

Published in final edited form as: Am J Hematol. 2023 Jan 1;98(2):348–358. doi: 10.1002/ajh.26796

TABLE 1.

Definitions of IgM-related phenomenon in macroglobulinemia

	IgM Monoclonal Component	Symptoms of Tumor Mass/Infiltration (Adenopathy Anemia)	Marrow Infiltration > 10%	IgM-Mediated Symptoms
MGUS	+	−	−	−
Smoldering macroglobulinemia	+	−	+	−
IgM-related disorder (eg, cold agglutinin hemolytic anemia, type II cryoglobulin, neuropathy, amyloidosis)	+	−	±	+
Macroglobulinemia	+	+	+	±

Abbreviations: IgM, immunoglobulin M; MGUS, monoclonal gammopathy of undetermined significance; +, positive; −, negative; ±, equivocal.