Dermatology Coding Alert

Question: How should we code the re-excision of a benign (as opposed to malignant) lesion? The path report indicated suspicious cells, so the surgeon performed a re-excision for border removal.

Kentucky Subscriber

Answer: The rules for lesion re-excision are the same whether the pathology report returns malignant or benign. If the re-excision occurs during the same operative session as the initial excision (for instance, due to pathology frozen section findings), you should code a single excision. Your size for the code selection should be "based on the final widest excised diameter required for complete tumor removal," according to CPT.

If the re-excision takes place at a later session, you'll need to select an excision code the same way you would for the initial excision. For benign lesions, select from codes such as 11400- 11446 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere]), trunk, arms or legs; ...) based on measuring "the greatest clinical diameter of the apparent lesion plus that margin required for complete excision."

Lesion excision codes include simple closure. If the re-excision requires intermediate or complex closure, you should code the service separately using the appropriate code from the range 12031-12057 (Repair, intermediate ...) or 13100-13153 (Repair, complex ...).

Don't forget modifier: If the re-excision takes place during the post-operative period, you'll need to append modifier 58 (Staged or related procedure or service by the same physician during the postoperative period).

Watch for medical necessity: Due to the concern for clear surgical margins to avoid the spread of cancer, lesion reexcision is far more common for a malignancy than for a benign lesion. Because the pathology report indicated "suspicious cells," you'd probably have a diagnosis code for a neoplasm of "uncertain behavior" rather than "benign." Such a code would be more likely to demonstrate medical necessity for a lesion re-excision.