Internal Medicine Coding Alert

Question: When I code my internist's lesion treatments, how can I tell when to choose an excision code over a biopsy code?

Minnesota Subscriber

Answer: Remember it this way: When the internist removes an entire lesion, select an excision code; if she removes part of a lesion, choose a biopsy code.

Excision example: A patient with a 3.2-mm lesion on her left arm reports to the internist. The internist makes an elliptical incision around the lesion and removes it entirely. Total excision diameter, including margins, is 3.5 cm.

In this case, you should choose an excision code based on the pathology report. If the report states that the lesion is benign, report 11404 (Excision, benign lesion, including margins, except skin tag [unless listed elsewhere], trunk, arms, or legs; excised diameter 3.1 to 4.0 cm).

If the lesion was malignant, choose 11604 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 3.1 to 4.0 cm) instead.

Biopsy example: A patient has a suspicious-looking raised lesion on his right thigh. The internist uses a punch tool to take a sample of the tissue.

For this patient, you should choose a biopsy code. On the claim, report 11100 (Biopsy of skin, subcutaneous tissue and/or mucous membrane [including simple closure], unless otherwise listed; single lesion). If the internist takes tissue from multiple lesions, report +11101 (... each separate/additional lesion [list separately in addition to code for primary procedure]) for each biopsy beyond the first.