ICD10BillableValid for clinical use
ICD-10 Code D38.4: Neoplasm of uncertain behavior of thymus
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).
When is it used?
- May be used when a clinician documents neoplasm of uncertain behavior of thymus in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
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.
Code hierarchy
chapter
2Neoplasms (C00-D49)
block
D37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
category
D38Neoplasm of uncertain behavior of middle ear and respiratory and intrathoracic organs
currentD38
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
OncologistGeneral Physician
Related codes
D38.0Neoplasm of uncertain behavior of larynxcodeD38.1Neoplasm of uncertain behavior of trachea, bronchus and lungcodeD38.2Neoplasm of uncertain behavior of pleuracodeD38.3Neoplasm of uncertain behavior of mediastinumcodeD38.5Neoplasm of uncertain behavior of other respiratory organscodeD38.6Neoplasm of uncertain behavior of respiratory organ, unspecifiedcode
Sibling codes
D38.0Neoplasm of uncertain behavior of larynxbillableD38.1Neoplasm of uncertain behavior of trachea, bronchus and lungbillableD38.2Neoplasm of uncertain behavior of pleurabillableD38.3Neoplasm of uncertain behavior of mediastinumbillableD38.5Neoplasm of uncertain behavior of other respiratory organsbillableD38.6Neoplasm of uncertain behavior of respiratory organ, unspecifiedbillable
Coverage-related procedures and services
CPT 88182high
FLOW CYTOMETRY, CELL CYCLE OR DNA ANALYSIS
Source: CMS coverage guidance
CPT 88185high
FLOW CYTOMETRY, CELL SURFACE, CYTOPLASMIC, OR NUCLEAR MARKER, TECHNICAL COMPONENT ONLY; EACH ADDITIONAL MARKER (LIST SEPARATELY IN ADDITION TO CODE FOR FIRST MARKER)
Source: CMS coverage guidance
CPT 88184high
FLOW CYTOMETRY, CELL SURFACE, CYTOPLASMIC, OR NUCLEAR MARKER, TECHNICAL COMPONENT ONLY; FIRST MARKER
Source: CMS coverage guidance
CPT 88189high
FLOW CYTOMETRY, INTERPRETATION; 16 OR MORE MARKERS
Source: CMS coverage guidance
CPT 88187high
FLOW CYTOMETRY, INTERPRETATION; 2 TO 8 MARKERS
Source: CMS coverage guidance
CPT 88188high
FLOW CYTOMETRY, INTERPRETATION; 9 TO 15 MARKERS
Source: CMS coverage guidance
Mapped diagnoses and classifications
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
D38.4
Common synonyms
Neoplasm of uncertain behavior of thymus
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.