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 mycosis fungoides 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
Official coding notes
Excludes1 (do not code together)
- peripheral T-cell lymphoma, not elsewhere classified (C84.4-)
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
C84.00Mycosis fungoides, unspecified sitecodeC84.01Mycosis fungoides, lymph nodes of head, face, and neckcodeC84.02Mycosis fungoides, intrathoracic lymph nodescodeC84.03Mycosis fungoides, intra-abdominal lymph nodescodeC84.04Mycosis fungoides, lymph nodes of axilla and upper limbcodeC84.05Mycosis fungoides, lymph nodes of inguinal region and lower limbcodeC84.06Mycosis fungoides, intrapelvic lymph nodescodeC84.07Mycosis fungoides, spleencodeC84.08Mycosis fungoides, lymph nodes of multiple sitescodeC84.09Mycosis fungoides, extranodal and solid organ sitescodeC84.0AMycosis fungoides, in remissioncode
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 404115006high
Bullous mycosis fungoides
Source: SNOMED International ICD-10 map
SNOMED_CT 765328000high
Classic mycosis fungoides
Source: SNOMED International ICD-10 map
SNOMED_CT 404114005high
Erythrodermic mycosis fungoides
Source: SNOMED International ICD-10 map
SNOMED_CT 404109006high
Follicular mucinosis type mycosis fungoides
Source: SNOMED International ICD-10 map
SNOMED_CT 404121005high
Generalised pagetoid reticulosis
Source: SNOMED International ICD-10 map
SNOMED_CT 404112009high
Granulomatous mycosis fungoides
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
C84.0
Replacement codes
C84.00 — Mycosis fungoides, unspecified siteC84.01 — Mycosis fungoides, lymph nodes of head, face, and neckC84.02 — Mycosis fungoides, intrathoracic lymph nodesC84.03 — Mycosis fungoides, intra-abdominal lymph nodesC84.04 — Mycosis fungoides, lymph nodes of axilla and upper limbC84.05 — Mycosis fungoides, lymph nodes of inguinal region and lower limbC84.06 — Mycosis fungoides, intrapelvic lymph nodesC84.07 — Mycosis fungoides, spleenC84.08 — Mycosis fungoides, lymph nodes of multiple sitesC84.09 — Mycosis fungoides, extranodal and solid organ sitesC84.0A — Mycosis fungoides, in remission
Common synonyms
Mycosis fungoides
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.