ICD-10 Code C90.32 – Solitary plasmacytoma in relapse (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C90.32 – Solitary plasmacytoma in relapse
What it is
C90.32 identifies a solitary plasmacytoma that has returned after prior remission or improvement. Use it when documentation clearly states relapse of a single plasma cell tumor rather than a new or unrelated condition.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe a localized plasma cell neoplasm with recurrence at the original site or another single site, often confirmed by imaging, biopsy, or specialist assessment.
When to use this code
Use this code when the provider documents solitary plasmacytoma in relapse, recurrent plasmacytoma, or return of a previously treated solitary lesion. It applies when the chart supports a single-site plasma cell tumor and the relapse status is explicit.
If the note only says history of plasmacytoma, remission, or active disease without relapse, check documentation before coding. Verify whether the condition is solitary plasmacytoma, multiple myeloma, or another plasma cell disorder.
Do not use for
Do not use this code for newly diagnosed solitary plasmacytoma without relapse, or for multiple myeloma and other plasma cell neoplasms. Check documentation when the recurrence status is unclear.
Coding tip
Code relapse only when the clinician explicitly links the current lesion to a prior solitary plasmacytoma.