Internal Medicine Coding Alert

Benign or malignant? Here's why you should never decide on your own

If you follow the proper steps toward selecting a code, lesion excision claims can be a breeze. But if one of those steps causes you to stumble, chances are good that your code choice will be inaccurate.

No worries: Check out this three-step guide to choosing the proper lesion excision code each and every time you code.

When reporting lesion excision, choose from 11400-11446 for benign lesions and 11600-11646 for malignant lesions, says Laura Smith, CPC, a dermatology coding specialist for MeritCare in Bemidji, Minn.

But how can you tell if a lesion is benign or malignant? You can't, which is why you should wait on the pathology report before choosing a code, Smith says.

Sometimes, the internist may not send the lesion to a pathologist because he is confident that the lesion is benign, says Shelley Bellm, CPC, physician relations and coding manager at Colorado Mountain Medical in Edwards. When this occurs, you should choose a benign lesion excision code.

But always let the physician make the final decision on lesion pathology. The coder should never, under any circumstances, decide the pathology of a lesion from the operative notes.

"A coder would not want to tag a patient with a malignant diagnosis without definitive proof," says Linda Martien, CPC, CPC-H, secretary of the AAPC National Advisory Board and coding specialist at the National Healing Corporation in Boca Raton, Fla.

In addition to the embarrassment it might cause everyone involved, a false cancer diagnosis could also open the practice up to legal trouble.

Once you have determined lesion type, you need to locate the body area where the physician excised the lesion. For coding purposes, CPT breaks lesion excision codes into four body areas, Smith says:

• trunk, arms, legs (11400-11406 for benign lesions, 11600-11606 for malignant)

• scalp, neck, hands, feet, genitalia (11420-11426 benign, 11620-11626 malignant)

• face, ears, eyelids, nose, lips, mucous membrane (11440-11446 benign)

• face, ears, eyelids, nose, lips (11640-11646 malignant).

So if encounter notes and the pathology report indicate that the internist excised a benign lesion from a patient's left thigh, you'd choose a code from the 11400-11406 family.

Next, you'll need to measure the total excision area of the lesion. Your code choice depends on the size of the lesion excision area.

Do this: According to CPT 2008: "Excision is defined as full-thickness (through the dermis) removal of a lesion, including margins, and includes simple (non-layered) closure when performed. Report each benign (or malignant) lesion excised separately. Code selection is determined by measuring the greatest diameter of the apparent lesion plus the margin required for complete excision (lesion diameter plus the most narrow margins required equals the excised diameter). The margins refer to the most narrow margin required to adequately excise the lesion, based on the physician's judgment."

Measure the greatest clinical diameter of the lesion, plus the margins required to completely excise the lesion, Bellm says. If you report an excision code based on "wound size only, you will shortchange the physician," she says. Also, remember to use measurements that the provider takes before excising the lesion.

Example: The internist excises a benign lesion from a patient's scalp. The greatest clinical diameter of the lesion is 2.2 cm, and the procedure required margins of 0.3 cm on each side.

In this instance, the total excision area is 2.8 cm (2.2 + 0.3 + 0.3), and your code choice is 11423 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere], scalp, neck, hands, feet, genitalia; excised diameter 2.1 to 3.0 cm).