2018 ICD-10-CM Diagnosis Code C7A

Malignant neuroendocrine tumors

Use Additional
Use Additional Help
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • code to identify any associated endocrine syndrome, such as:
  • carcinoid syndrome (
    ICD-10-CM Diagnosis Code E34.0

    Carcinoid syndrome

      2016 2017 2018 Billable/Specific Code
    • May be used as an additional code to identify functional activity associated with a carcinoid tumor.
Code Also
Code Also Help
A code also note instructs that 2 codes may be required to fully describe a condition but the sequencing of the two codes is discretionary, depending on the severity of the conditions and the reason for the encounter.
  • any associated multiple endocrine neoplasia [MEN] syndromes (
    ICD-10-CM Diagnosis Code E31.2

    Multiple endocrine neoplasia [MEN] syndromes

      2016 2017 2018 Non-Billable/Non-Specific Code
    Applicable To
    • Multiple endocrine adenomatosis
    Code Also
    • any associated malignancies and other conditions associated with the syndromes
Type 2 Excludes
Type 2 Excludes Help
A type 2 excludes note represents "not included here". A type 2 excludes note indicates that the condition excluded is not part of the condition it is excluded from but a patient may have both conditions at the same time. When a type 2 excludes note appears under a code it is acceptable to use both the code (C7A) and the excluded code together.
  • malignant pancreatic islet cell tumors (
    ICD-10-CM Diagnosis Code C25.4

    Malignant neoplasm of endocrine pancreas

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Malignant neoplasm of islets of Langerhans
    Use Additional
    • code to identify any functional activity.
  • Merkel cell carcinoma (
    ICD-10-CM Diagnosis Code C4A
    • C4A Merkel cell carcinoma
      • C4A.0 Merkel cell carcinoma of lip
      • C4A.1 Merkel cell carcinoma of eyelid, including ca...
        • C4A.10 Merkel cell carcinoma of unspecified eyelid, ...
        • C4A.11 Merkel cell carcinoma of right eyelid, includ...
        • C4A.12 Merkel cell carcinoma of left eyelid, includi...
      • C4A.2 Merkel cell carcinoma of ear and external aur...
        • C4A.20 Merkel cell carcinoma of unspecified ear and ...
        • C4A.21 Merkel cell carcinoma of right ear and extern...
        • C4A.22 Merkel cell carcinoma of left ear and externa...
      • C4A.3 Merkel cell carcinoma of other and unspecifie...
        • C4A.30 Merkel cell carcinoma of unspecified part of ...
        • 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, includin...
        • C4A.60 Merkel cell carcinoma of unspecified upper li...
        • C4A.61 Merkel cell carcinoma of right upper limb, in...
        • C4A.62 Merkel cell carcinoma of left upper limb, inc...
      • C4A.7 Merkel cell carcinoma of lower limb, includin...
        • C4A.70 Merkel cell carcinoma of unspecified lower li...
        • C4A.71 Merkel cell carcinoma of right lower limb, in...
        • C4A.72 Merkel cell carcinoma of left lower limb, inc...
      • C4A.8 Merkel cell carcinoma of overlapping sites
      • C4A.9 Merkel cell carcinoma, unspecified
The following code(s) above C7A contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to C7A:
  • C00-D49
    2018 ICD-10-CM Range C00-D49


    • Functional activity
    • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
    • Morphology [Histology]
    • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
    • Primary malignant neoplasms overlapping site boundaries
    • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
    • Malignant neoplasm of ectopic tissue
    • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Code History
Code annotations containing back-references to C7A:
ICD-10-CM Codes Adjacent To C7A
C74.92 Malignant neoplasm of unspecified part of left adrenal gland
C75 Malignant neoplasm of other endocrine glands and related structures
C75.0 Malignant neoplasm of parathyroid gland
C75.1 Malignant neoplasm of pituitary gland
C75.2 Malignant neoplasm of craniopharyngeal duct
C75.3 Malignant neoplasm of pineal gland
C75.4 Malignant neoplasm of carotid body
C75.5 Malignant neoplasm of aortic body and other paraganglia
C75.8 Malignant neoplasm with pluriglandular involvement, unspecified
C75.9 Malignant neoplasm of endocrine gland, unspecified
C7A Malignant neuroendocrine tumors
C7A.0 Malignant carcinoid tumors
C7A.00 Malignant carcinoid tumor of unspecified site
C7A.01 Malignant carcinoid tumors of the small intestine
C7A.010 Malignant carcinoid tumor of the duodenum
C7A.011 Malignant carcinoid tumor of the jejunum
C7A.012 Malignant carcinoid tumor of the ileum
C7A.019 Malignant carcinoid tumor of the small intestine, unspecified portion
C7A.02 Malignant carcinoid tumors of the appendix, large intestine, and rectum
C7A.020 Malignant carcinoid tumor of the appendix
C7A.021 Malignant carcinoid tumor of the cecum

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