Extramedullary plasmacytoma not having achieved remission

This code signifies a malignant plasma cell neoplasm that originates outside of the bone marrow, specifically when the disease has not yet achieved a state of remission. It represents an active, extramedullary proliferation of plasma cells.

Use this code for patients diagnosed with an extramedullary plasmacytoma that is currently active and has not responded to treatment sufficiently to be considered in remission. Documentation should clearly state "extramedullary plasmacytoma" and indicate ongoing disease or lack of remission.

• Distinguish from multiple myeloma (C90.0-) or solitary plasmacytoma of bone (C90.1-).
• Ensure documentation explicitly states "extramedullary" and "not having achieved remission."
• Do not use if the patient is in remission; instead, consider codes for personal history of plasmacytoma (Z85.79).