General Surgery Coding Alert

ICD-10:

173 to C44: Look for Close Malignant Skin Neoplasm Crosswalk

Melanoma and more report to different codes.

Not a lot will change once you start reporting malignant skin neoplasms with ICD-10, but we have the low-down on a few key differences to keep your diagnosis coding on track for skin biopsy and excision cases.

Recall: CMS has finalized the ICD-10 implementation date for Oct. 1, 2014, delaying the action one year from the original deadline.

Stay the Course for Excludes/Includes

Both C44 in ICD-10 and 173 in ICD-9 (Other and unspecified malignant neoplasm of skin) include malignant neoplasm of sebaceous glands. The two code families also share the same condition exclusions, as follows:

  • Kaposi's sarcoma of skin (C46.0) (176.0-176.9)
  • malignant melanoma of skin (C43.-) (172.0-172.9)
  • malignant neoplasm of skin of genital organs (C51-C52, C60.-, C63.2) (184.0-184.9, 187.1-187.9)
  • Merkel cell carcinoma of skin (C4A.-) (209.31-209.36).

Expect Greater ICD-10 Site Detail

You'll find a direct crosswalk between other and unspecified neoplasm of skin codes for ICD-9 and ICD-10 at the fourth-digit level, as follows:

  • 173.0 -- ... lip crosswalks to C44.0 (same definition)
  • 173.1 -- ... eyelid, including canthus crosswalks to C44.1 (same definition)
  • 173.2 -- ... ear and external auditory canal crosswalks to C44.2 (ear and external auricular canal)
  • 173.3 -- ... other and unspecified parts of face crosswalks to C44.3 (same definition)
  • 173.4 -- ... Scalp and skin of neck crosswalks to C44.4 (scalp and neck)
  • 173.5 -- ... Skin of trunk, except scrotum crosswalks to C44.5 (trunk)
  • 173.6 -- ... Skin of upper limb, including shoulder crosswalks to C44.6 (same definition)
  • 173.7 -- ... Skin of lower limb, including hip crosswalks to C44.7 (same definition)
  • 173.8 -- ... Other specified sites of skin (text note: malignant neoplasm of contiguous or overlapping sites of skin whose point of origin cannot be determined) crosswalks to C44.8 (overlapping sites of skin)
  • 173.9 -- ... Skin, site unspecified crosswalks to C44.9 (same definition).

You'll also find fifth-digit agreement between ICD-9 and ICD-10 for these codes, as follows:

  • 0 -- Unspecified malignant neoplasm of ...
  • 1 -- Basal cell carcinoma of ...
  • 2 -- Squamous cell carcinoma of ...
  • 9 -- Other specified malignant neoplasm of ...

Embrace the difference: The one significant change from ICD-9 to ICD-10 for these codes is the addition of a sixth digit to further zero in on the lesion site.

For bilateral sites (eyelid, C44.1_; ear, C44.2_; upper limb, C44.6_; lower limb, C44.7_) you'll have the following three choices for sixth digits:

  • 1 -- unspecified
  • 2 -- right
  • 9 -- left.

The sixth digit definitions are a little different form some sites, as follows:

  • C44.3_ -- ... other and unspecified parts of face

1 -- unspecified
2 -- nose
9 -- other parts of face

  • C44.5_ -- ... trunk

1 -- anal/perianal
2 -- breast
9 -- other part of trunk.

There are no sixth digit options for C44.0_, C44.4_, C44.8_ and C44.9_.