General Surgery Coding Alert

Question: Our surgeon excised a skin lesion that measured 1 cm x 0.5 cm with a 0.2 cm margin all around. The codes are based on “excised diameter.” How can you determine the diameter when the lesion isn’t round? What is the correct code for this service?

Arkansas Subscriber

Answer: CPT^® defines a lesion excision diameter as the longest dimension of the lesion plus the most narrow margin on both sides (two times the margin) required to remove the lesion. That means in the case you describe, the excised diameter would be 1 cm plus 2 x 0.2 cm = 1.4 cm.

To answer the second part of your question, you need to know two pieces of information that you don’t provide. The first is the anatomic site of the lesion. The second whether the lesion is benign or malignant.

Let’s say the lesion is on the patient’s leg. For a benign lesion of this size, the correct code is 11402 (Excision, benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms or legs; excised diameter 1.1 to 2.0 cm). If the lesion at this site were malignant, the correct code would be 11602 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 1.1 to 2.0 cm).