ICD10BillableValid for clinical use
ICD-10 Code C78.5: Secondary malignant neoplasm of large intestine and rectum
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 secondary malignant neoplasm of large intestine and rectum 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
C00-C96Malignant neoplasms
block
C76-C80Malignant neoplasms of ill-defined, other secondary and unspecified sites
category
C78Secondary malignant neoplasm of respiratory and digestive organs
currentC78
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
C78.0Secondary malignant neoplasm of lungcategoryC78.1Secondary malignant neoplasm of mediastinumcodeC78.2Secondary malignant neoplasm of pleuracodeC78.3Secondary malignant neoplasm of other and unspecified respiratory organscategoryC78.4Secondary malignant neoplasm of small intestinecodeC78.6Secondary malignant neoplasm of retroperitoneum and peritoneumcodeC78.7Secondary malignant neoplasm of liver and intrahepatic bile ductcodeC78.8Secondary malignant neoplasm of other and unspecified digestive organscategory
Sibling codes
C78.0Secondary malignant neoplasm of lungC78.1Secondary malignant neoplasm of mediastinumbillableC78.2Secondary malignant neoplasm of pleurabillableC78.3Secondary malignant neoplasm of other and unspecified respiratory organsC78.4Secondary malignant neoplasm of small intestinebillableC78.6Secondary malignant neoplasm of retroperitoneum and peritoneumbillableC78.7Secondary malignant neoplasm of liver and intrahepatic bile ductbillableC78.8Secondary malignant neoplasm of other and unspecified digestive organs
Coverage-related procedures and services
CPT 81479high
UNLISTED MOLECULAR PATHOLOGY PROCEDURE
Source: CMS coverage guidance
CPT 44388high
COLONOSCOPY THROUGH STOMA; DIAGNOSTIC, INCLUDING COLLECTION OF SPECIMEN(S) BY BRUSHING OR WASHING, WHEN PERFORMED (SEPARATE PROCEDURE)
Source: CMS coverage guidance
CPT 44401high
COLONOSCOPY THROUGH STOMA; WITH ABLATION OF TUMOR(S), POLYP(S), OR OTHER LESION(S) (INCLUDES PRE-AND POST-DILATION AND GUIDE WIRE PASSAGE, WHEN PERFORMED)
Source: CMS coverage guidance
CPT 44389high
COLONOSCOPY THROUGH STOMA; WITH BIOPSY, SINGLE OR MULTIPLE
Source: CMS coverage guidance
CPT 44391high
COLONOSCOPY THROUGH STOMA; WITH CONTROL OF BLEEDING, ANY METHOD
Source: CMS coverage guidance
CPT 44402high
COLONOSCOPY THROUGH STOMA; WITH ENDOSCOPIC STENT PLACEMENT (INCLUDING PRE- AND POST-DILATION AND GUIDE WIRE PASSAGE, WHEN PERFORMED)
Source: CMS coverage guidance
Mapped diagnoses and classifications
SNOMED_CT 1237479000high
Metastatic carcinoma to anal canal
Source: SNOMED International ICD-10 map
SNOMED_CT 1237460003high
Metastatic carcinoma to ascending colon
Source: SNOMED International ICD-10 map
SNOMED_CT 1237427001high
Metastatic carcinoma to caecum
Source: SNOMED International ICD-10 map
SNOMED_CT 1237484006high
Metastatic carcinoma to colon
Source: SNOMED International ICD-10 map
SNOMED_CT 1237455002high
Metastatic carcinoma to descending colon
Source: SNOMED International ICD-10 map
SNOMED_CT 1237456001high
Metastatic carcinoma to hepatic flexure
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
C78.5
Common synonyms
Secondary malignant neoplasm of large intestine and rectum
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.