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 sézary disease 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
C84Mature T/NK-cell lymphomas
currentC84
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
C84.10Sézary disease, unspecified sitecodeC84.11Sézary disease, lymph nodes of head, face, and neckcodeC84.12Sézary disease, intrathoracic lymph nodescodeC84.13Sézary disease, intra-abdominal lymph nodescodeC84.14Sézary disease, lymph nodes of axilla and upper limbcodeC84.15Sézary disease, lymph nodes of inguinal region and lower limbcodeC84.16Sézary disease, intrapelvic lymph nodescodeC84.17Sézary disease, spleencodeC84.18Sézary disease, lymph nodes of multiple sitescodeC84.19Sézary disease, extranodal and solid organ sitescodeC84.1ASézary disease, in remissioncode
Sibling codes
C84.0Mycosis fungoidesC84.4Peripheral T-cell lymphoma, not elsewhere classifiedC84.6Anaplastic large cell lymphoma, ALK-positiveC84.7Anaplastic large cell lymphoma, ALK-negativeC84.ACutaneous T-cell lymphoma, unspecifiedC84.ZOther mature T/NK-cell lymphomasC84.9Mature T/NK-cell lymphomas, unspecified
Mapped diagnoses and classifications
SNOMED_CT 118611004high
Sezary's disease
Source: SNOMED International ICD-10 map
SNOMED_CT 188633006high
Sezary's disease of lymph nodes of axilla and upper limb
Source: SNOMED International ICD-10 map
SNOMED_CT 1255799000high
Sézary disease of lymph nodes of head
Source: SNOMED International ICD-10 map
SNOMED_CT 1255801002high
Sézary disease of lymph nodes of head and neck
Source: SNOMED International ICD-10 map
SNOMED_CT 1255800001high
Sézary disease of lymph nodes of neck
Source: SNOMED International ICD-10 map
SNOMED_CT 688271000119100high
Sézary syndrome of inguinal 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
C84.1
Replacement codes
C84.10 — Sézary disease, unspecified siteC84.11 — Sézary disease, lymph nodes of head, face, and neckC84.12 — Sézary disease, intrathoracic lymph nodesC84.13 — Sézary disease, intra-abdominal lymph nodesC84.14 — Sézary disease, lymph nodes of axilla and upper limbC84.15 — Sézary disease, lymph nodes of inguinal region and lower limbC84.16 — Sézary disease, intrapelvic lymph nodesC84.17 — Sézary disease, spleenC84.18 — Sézary disease, lymph nodes of multiple sitesC84.19 — Sézary disease, extranodal and solid organ sitesC84.1A — Sézary disease, in remission
Common synonyms
Sézary disease
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.