Dermatology Coding Alert

Also: Big changes coming to in situ coding.

Even though ICD-10 implementation has been delayed, it doesn't mean you still shouldn't be preparing -- especially with these drastic changes coming to your skin melanoma coding.

You'll need to be ready for an important melanoma coding distinction once you're required to use the new code set, which has a proposed implementation date of Oct. 1, 2014.

Code for Site

ICD-9 provides one code family for melanoma of skin (excluding skin of genital organs or sites other than skin): 172.x (Malignant melanoma of skin). A fourth digit designates the melanoma site as follows:

• 172.0 -- Lip
• 172.1 -- Eyelid, including canthus
• 172.3 -- Other and unspecified parts of face
• 172.4 -- Scalp and neck
• 172.5 -- Trunk, except scrotum
• 172.6 -- Upper limb, including shoulder
• 172.7 -- Lower limb, including hip
• 172.8 -- Other specified sites of skin
• 172.9 -- Site unspecified.

ICD-10 provides similar site-specific codes in the family C43 (Malignant melanoma of skin). You'll have more site specificity with the new codes, however, because ICD-10 adds a fourth digit for the ear (C43.2x, Ear and external auricular canal).

That's not all: ICD-10 also adds a fifth digit that provides greater specificity. For instance, C43.1x further defines the melanoma site as follows:

• C43.10 -- Malignant melanoma of unspecified eyelid, including canthus
• C43.11 -- Malignant melanoma of right eyelid, including canthus
• C43.12 -- Malignant melanoma of left eyelid, including canthus.

The right/left distinction isn't the only way the fifth digit increases site-specificity. For instance, 172.3 crosswalks to the following three codes for ICD-10:

• C43.30 -- Malignant melanoma of unspecified part of face
• C43.31 -- Malignant melanoma of nose
• C43.39 -- Malignant melanoma of other parts of face.

In Situ is Different

But the biggest change you'll find for melanoma coding is that ICD-9 includes melanoma in situ of skin in the 172 family, while ICD-10 provides a different code family for melanoma in situ (D03, Melanoma in situ). You'll also report the D03 codes with the same fourth or fifth digits to specify the melanoma in situ site.

For example: You'd currently report melanoma of skin of scalp and neck as 172.4, including melanoma in situ. But under ICD-10, you'll have to choose between the following codes:

• C43.4 -- Malignant melanoma of scalp and neck
• D03.4 -- Melanoma in situ of scalp and neck.

Documentation: When choosing your ICD-10-CM code, you will first need to confirm that the location of the melanoma is the scalp or neck. Next you will need to determine whether the melanoma is documented as "in situ." The National Cancer Institute indicates that melanoma in situ is stage 0 melanoma (www.cancer.gov/cancertopics/pdq/treatment/melanoma/Patient/page2). The abnormal cells are located in the epidermis in stage 0 melanoma.

If the documentation indicates stage I or above, or indicates that the melanoma has metastasized, you'll know that the melanoma is not in situ.

Coder tips: Code C43.- excludes melanoma in situ using an Excludes1 note. It indicates that the excluded diagnosis (D03.x, melanoma in situ) should never be used at the same time as the code that has the Excludes1 note (C43.x). Excludes1 is used when two conditions cannot occur together, such as a congenital form and an acquired form of the same condition.