Convert to ICD-10-CM: 
203.80 converts approximately to:
- 2015/16 ICD-10-CM C88.8 Other malignant immunoproliferative diseases
Or:
 - 2015/16 ICD-10-CM C90.20 Extramedullary plasmacytoma not having achieved remission
Or:
 - 2015/16 ICD-10-CM C90.30 Solitary plasmacytoma not having achieved remission