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  2. ICD-10-CM Codes List
  3. C00–D49
  4. C43-C44
  5. Merkel cell carcinoma (C4A)

Merkel cell carcinoma (C4A)

The ICD-10 code section C4A is used to classify and code Merkel cell carcinoma, a rare and aggressive type of skin cancer. These codes specify the cancer's location, such as the lip, eyelid, ear, face, scalp, trunk, or limbs, helping healthcare providers accurately document and treat this malignancy.

Merkel cell carcinoma is referenced by the general code C4A, while more specific codes like C4A.0 (Merkel cell carcinoma of lip) and C4A.11 (right eyelid) detail exact tumor sites. Synonyms such as "primary carcinoma of lip" or "primary malignant neoplasm of skin of ear" assist coders in linking common terms to the right ICD-10 code for precision. This section also covers overlapping or unspecified sites with codes like C4A.8 and C4A.9. Using these specific codes ensures proper medical coding and supports targeted clinical management for this skin cancer variant, making them vital for healthcare professionals and medical coders working with skin malignancies.

  • Neoplasms (C00–D49)

    • Melanoma and other malignant neoplasms of skin (C43-C44)

        • Merkel cell carcinoma (C4A)

        • C4A Merkel cell carcinoma
        • C4A.0 Merkel cell carcinoma of lip
        • C4A.1 Merkel cell carcinoma of eyelid, including canthus
        • C4A.10 Merkel cell carcinoma of unspecified eyelid, including canthus
        • C4A.11 Merkel cell carcinoma of right eyelid, including canthus
        • C4A.111 Merkel cell carcinoma of right upper eyelid, including canthus
        • C4A.112 Merkel cell carcinoma of right lower eyelid, including canthus
        • C4A.12 Merkel cell carcinoma of left eyelid, including canthus
        • C4A.121 Merkel cell carcinoma of left upper eyelid, including canthus
        • C4A.122 Merkel cell carcinoma of left lower eyelid, including canthus
        • C4A.2 Merkel cell carcinoma of ear and external auricular canal
        • C4A.20 Merkel cell carcinoma of unspecified ear and external auricular canal
        • C4A.21 Merkel cell carcinoma of right ear and external auricular canal
        • C4A.22 Merkel cell carcinoma of left ear and external auricular canal
        • C4A.3 Merkel cell carcinoma of other and unspecified parts of face
        • C4A.30 Merkel cell carcinoma of unspecified part of face
        • C4A.31 Merkel cell carcinoma of nose
        • C4A.39 Merkel cell carcinoma of other parts of face
        • C4A.4 Merkel cell carcinoma of scalp and neck
        • C4A.5 Merkel cell carcinoma of trunk
        • C4A.51 Merkel cell carcinoma of anal skin
        • C4A.52 Merkel cell carcinoma of skin of breast
        • C4A.59 Merkel cell carcinoma of other part of trunk
        • C4A.6 Merkel cell carcinoma of upper limb, including shoulder
        • C4A.60 Merkel cell carcinoma of unspecified upper limb, including shoulder
        • C4A.61 Merkel cell carcinoma of right upper limb, including shoulder
        • C4A.62 Merkel cell carcinoma of left upper limb, including shoulder
        • C4A.7 Merkel cell carcinoma of lower limb, including hip
        • C4A.70 Merkel cell carcinoma of unspecified lower limb, including hip
        • C4A.71 Merkel cell carcinoma of right lower limb, including hip
        • C4A.72 Merkel cell carcinoma of left lower limb, including hip
        • C4A.8 Merkel cell carcinoma of overlapping sites
        • C4A.9 Merkel cell carcinoma, unspecified