General Surgery Coding Alert

For 2003, CPT significantly revises its guidelines for reporting excision of benign (11400-11471) and malignant (11600-11646) lesions, and now specifies that physicians should include margins in addition to lesion diameter when choosing an appropriate code. For the greatest accuracy, physicians and coders must also consider the timing of measurements and excisions, and apply modifiers as necessary.

Because 11400-11471 and 11600-11646 are "size-based" codes (for example, 11400, Excision, benign lesion including margins, except skin tag [unless listed elsewhere], trunk, arms or legs; excised diameter 0.5 cm or less; versus 11404 ... excised diameter 3.1 to 4.0 cm), properly determining the diameter of the area excised is of primary importance when reporting lesion excision. Unlike previous years, CPT 2003 instructs physicians to include the margins the normal-appearing tissue around the lesion that the surgeon excises to ensure complete removal of any biological extension of the tumor when measuring the excised diameter. The distinction is important. Many physicians and coders, familiar with the "old" CPT guidelines, may inadvertently or absentmindedly continue to choose excision codes based on lesion diameter only, but this will almost always lead to an incorrect code under the new guidelines.

To determine the total excised diameter, calculate the lesion diameter at its widest point (the crucial measurement under the old guidelines) plus the width of the margin at its narrowest point, says Allan Wirtzer, MD, a dermatologist in private practice at Mid-Valley Dermatology in Sherman Oaks, Calif., who helped develop the codes as the American Academy of Dermatology's representative to the CPT Advisory Committee.

For example, the surgeon excises an irregularly shaped, malignant lesion (see Figure 1, right) from a patient's left shoulder. The lesion measures 1.5 cm at its widest. To ensure removal of all malignancy, the surgeon allows a margin of at least 1.5 cm on all sides. In this case, add the size of the lesion (1.5 cm) and the width of the narrowest margin (1.5 cm top, 1.5 cm bottom) for a total of 4.5 cm (1.5 + 1.5 + 1.5 = 4.5). Therefore, the appropriate code is 11606 (Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter over 4.0 cm).

Just as important as determining the diameter of excision correctly is taking the measurement at the appropriate time: that is, prior to excision. The pathology report will not provide an accurate measurement because lesions shrink when placed in formaldehyde, says Kathy Pride, CPC, CCS-P, HIM applications specialist with QuadraMed based in San Rafael, Calif. Relying on the pathology report will mean smaller measurements and a consequent loss in legitimate compensation.

Timing also plays a crucial role in subsequent excisions if a frozen-section pathology shows that the margins of the initial excision were not adequate to remove the tumor completely. For example, the surgeon removes a malignant lesion 2.5 cm in diameter, including margins, from the back of the hand. Following examination, however, the lab report reveals the need to excise an additional 2 cm of margin on all sides to guarantee that the physician has removed all malignant tissue.

If the surgeon performs the re-excision during the same operative session, you may report only a single code to describe both the excision and re-excision, based on the widest overall excision diameter, including margins. In the above example, the total area is 6.5 cm (2.5-cm original excision + 2-cm additional margin during re-excision, top + 2-cm additional margin during re-excision, bottom = 6.5 cm). In this case, report 11626 (Excision, malignant lesion including margins, scalp, neck, hands, feet, genitalia; excised diameter over 4.0 cm).

If the surgeon must return to the operating room (OR) for a subsequent session to perform the re-excision during the postoperative period of the initial excision, you may report a second excision code (in addition to the initial excision), but you must attach modifier -58 (Staged or related procedure or service by the same physician during the postoperative period) to the second excision code. Returning to the above example, the surgeon reports 11623 (... excised diameter 2.1 to 3.0 cm) for the initial excision. Two weeks later, she schedules a repeat operative session to excise an additional 2 cm of margin on all sides. For the second session, appropriate coding is 11626-58.

Pride reminds coders that they should wait until the pathology report returns before choosing a diagnosis of benign or malignant lesion. Medicare does not prohibit this practice, and it guarantees more accurate coding and eliminates the need for refiling inaccurate claims.

There is one exception. If the surgeon performs a re-excision to remove additional margins at a subsequent operative session (as described above), you may automatically report the same malignant diagnosis you linked to the initial excision. This is true even if the pathology report on the second excision returns benign, because the original reason for the re-excision was malignancy.

For instance, the surgeon removes a 2.5-cm malignant lesion from the hand and returns to the OR several days later to remove additional margins, as in the above example. In the first session, you should link a diagnosis of 173.6 (Other malignant neoplasm of skin; skin of upper limb, including shoulder) to 11623. Because the initial malignancy prompted the return to the OR, you should cite the same diagnosis with 11626-58 for the second session, even if the subsequent pathology report reveals no malignancy in the additional margins excised.

When reporting multiple excisions, do not "add together" the excised diameter of the lesions, as you would add together the lengths of multiple wounds for wound repair, for example. Rather, each excision is reported independently. "It's more work to excise two 1-cm lesions than a single 2-cm lesion," says Laureen Jandroep, OTR, CPC, CCS-P, CPC-H, CCS, director and senior instructor for CRN Institute, an online coding certification training center based in Absecon, N.J. "If you add together the two 1-cm lesions and report it as a single 2-cm lesion, you're losing reimbursement and tainting the medical record. What you're coding is not an accurate representation of what the physician did."

When reporting multiple excisions, you should attach a verifiable diagnosis to each individual removal code. In addition, append modifier -59 (Distinct procedural service) to the second and subsequent codes to indicate the separate nature of each lesion and to avoid "duplication" denials.

For example, if the surgeon removes three lesions from the left arm, sizes 1 cm (benign), 1.5 cm (benign) and 2.5 cm (malignant), report 11401 with 216.6 (Benign neoplasm of skin; skin of upper limb, including shoulder), 11402-59 with 216.6, and 11603-59 with 173.6.