Dermatology Coding Alert

Question: The dermatologist's notes state that he removed a "Clark's nevus." What exactly is that? Is there a special code for it?

South Carolina Subscriber

Answer: "Clark's nevus" is another term for an atypical mole (AM). Physicians also sometimes call AMs active junctional nevi, atypical melanocytic nevi, B-K moles, dysplastic nevi, and dysplastic moles.

Unlike common moles, AMs vary in color, ranging from tan to dark brown shades on a pink background. They have irregular borders that may include notches. Although technically an AM is "pre-cancerous" -- meaning that it is more likely to turn into a melanoma than a regular mole -- dermatologists consider it a benign neoplasm, and you should code the diagnosis as such.

For the diagnosis, choose a code in category 216 based on the specific site of the Clark's nevus. For example, if the AM appears on the patient's neck, code it 216.4 (Benign neoplasm of skin; scalp and skin of neck).

However, evidence also suggests that patients with a family history of melanoma are at greater risk for the AM to progress into a melanoma. Therefore, for a patient with a family history of melanoma, use V16.8 (Family history of other specified malignant neoplasm) to indicate that the family history exists.