ICD10
ICD-10 Code C96.2: Malignant mast cell neoplasm
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).
When is it used?
- May be used when a clinician documents malignant mast cell neoplasm in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
2Neoplasms (C00-D49)
block
C00-C96Malignant neoplasms
block
C81-C96Malignant neoplasms of lymphoid, hematopoietic and related tissue
category
C96Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue
currentC96
Official coding notes
Excludes1 (do not code together)
- indolent mastocytosis (D47.02)
- mast cell leukemia (C94.30)
- mastocytosis (congenital) (cutaneous) (Q82.2)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
OncologistGeneral Physician
Related codes
Sibling codes
C96.0Multifocal and multisystemic (disseminated) Langerhans-cell histiocytosisbillableC96.4Sarcoma of dendritic cells (accessory cells)billableC96.5Multifocal and unisystemic Langerhans-cell histiocytosisbillableC96.6Unifocal Langerhans-cell histiocytosisbillableC96.AHistiocytic sarcomabillableC96.ZOther specified malignant neoplasms of lymphoid, hematopoietic and related tissuebillableC96.9Malignant neoplasm of lymphoid, hematopoietic and related tissue, unspecifiedbillable
Mapped diagnoses and classifications
SNOMED_CT 716655008high
Aggressive systemic mastocytosis
Source: SNOMED International ICD-10 map
SNOMED_CT 699537002high
Erdheim-Chester disease
Source: SNOMED International ICD-10 map
SNOMED_CT 188668006high
Malignant mast cell sarcoma of spleen
Source: SNOMED International ICD-10 map
SNOMED_CT 93200005high
Malignant mast cell tumor of intra-abdominal lymph nodes
Source: SNOMED International ICD-10 map
SNOMED_CT 93201009high
Malignant mast cell tumor of intrapelvic lymph nodes
Source: SNOMED International ICD-10 map
SNOMED_CT 93202002high
Malignant mast cell tumor of intrathoracic lymph nodes
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
C96.2
Replacement codes
C96.20 — Malignant mast cell neoplasm, unspecifiedC96.21 — Aggressive systemic mastocytosisC96.22 — Mast cell sarcomaC96.29 — Other malignant mast cell neoplasm
Common synonyms
Malignant mast cell neoplasm
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.