C4A.121
BillableMerkel cell carcinoma of left upper eyelid, inc canthus
Merkel cell carcinoma of left upper eyelid, including canthus
Cross-references
UMLS
How C4A.121 differs from sibling codes
All children of C4A.12 share the same parent. The wording below is what mechanically separates each sibling from C4A.121.
Also Known As / Clinical Terms(9)
SNOMED CT
UMLS
Clinical Terms
- Primary malignant neoplasm of skin of left upper eyelid
- Primary Merkel cell carcinoma of skin of left upper eyelid
- Primary Merkel cell carcinoma of skin of upper eyelid
Common questions
What is the ICD-10-CM code for Merkel cell carcinoma of left upper eyelid, inc canthus?
Merkel cell carcinoma of left upper eyelid, inc canthus is coded as C4A.121 in ICD-10-CM.
What is ICD-10 code C4A.121?
C4A.121 is the ICD-10-CM identifier for Merkel cell carcinoma of left upper eyelid, inc canthus. It is included in the official 2025 release of ICD-10-CM published by CMS and NCHS.
Is C4A.121 a billable code?
Yes, C4A.121 is a billable / specific ICD-10-CM code that can be used to indicate a diagnosis on a medical claim.
What is the parent code of C4A.121?
C4A.121 sits under C4A.12 (Merkel cell carcinoma of left eyelid, including canthus) in the ICD-10-CM hierarchy.
What chapter does C4A.121 belong to?
C4A.121 is in Chapter 2: Neoplasms.
What are the synonyms for Merkel cell carcinoma of left upper eyelid, inc canthus?
In clinical text, merkel cell carcinoma of left upper eyelid, inc canthus is also written as: Primary Merkel cell carcinoma of skin of left upper eyelid, Primary Merkel cell carcinoma of skin of upper eyelid, Primary malignant neoplasm of skin of left upper eyelid, Merkel Cell Carcinoma of Left Upper Eyelid, Including Canthus, Merkel cell carcinoma of left upper eyelid, including canthus. Sourced from SNOMED CT, UMLS Metathesaurus, and clinical-terms enrichment.
Why does C4A.121 map to multiple SNOMED CT concepts?
ICD-10-CM is a billing classification with broader categories than SNOMED CT’s clinical terminology. C4A.121 captures the billing-level concept; SNOMED CT splits it into 3 clinical concepts: 1332235007, 16905581000119107, 16906021000119109.
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.