ICD-10 Code C96.22 – Mast cell sarcoma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C96.22 – Mast cell sarcoma
What it is
C96.22 identifies mast cell sarcoma, a rare malignant neoplasm of mast cells. Use it when documentation specifically names this diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Reports may describe a localized tumor composed of atypical mast cells with aggressive behavior and possible tissue invasion.
When to use this code
Use C96.22 when the provider documents mast cell sarcoma as the confirmed diagnosis. It may appear in pathology, oncology, or discharge records. Do not infer it from a nonspecific mast cell disorder or from suspected disease alone.
Do not use for
Do not use this code for mastocytosis, mast cell leukemia, or other mast cell neoplasms unless mast cell sarcoma is documented. Check documentation if the pathology wording is unclear.
Coding tip
Code the exact tumor type stated in the final diagnosis, and query the provider if the record only says “mast cell neoplasm.”