Table 1.

Diagnostic criteria for solitary plasmacytoma and overlapping disorders

		Plasmacytoma	Serum monoclonal protein	Bone marrow cytology	End organ damage	Radiological work-up	Risk of progression
Solitary plasmacytoma	Solitary plasmacytoma	Present	Not required	Negative		No other lesions	10% will progress to MM within 3 years
	Solitary plasmacytoma with minimal bone marrow involvement	Present	Not required	Monoclonal PC infiltration < 10%	Absent	No other lesions	60% with SBP or 20% with EMP will progress to MM within 3 years
Multiple myeloma	Macrofocal myeloma	Present	Not required	Monoclonal PC infiltration < 10%	Possible	Multiple lesions
	Multiple myeloma	Not required	Present	Monoclonal PC infiltration ≥ 10%	Present	Other lesions could be present

Abbreviations: MM multiple myeloma, BM bone marrow, PC plasma cell, EMP extrameddulary plasmacytoma