Dermatology Coding Alert

Question:  I just received a pathology report back that reads: "The largest segment measures 3.5 x 3.5 x 2.0 cm. A second fragment measures 3.0 x 3.0 x 3.0 cm and then in aggregate, the smaller fragments measure 3.5 x 3.0 x 2.0cm." The dermatologist excised these lesions from the patient’s back and neck. How should I code this?

Missouri Subscriber

Answer: You cannot code this excision solely from the pathology report. You need to go back to the physician’s record of the procedure. You should select the appropriate lesion excision size code based on the physician’s report.

Once the specimen is put in the jar and sent to pathology, the specimen shrinks down, sometimes to half its original size. CPT’s excision sizes, including margins, are based on the physician’s measurements at the time of the excision. Your dermatologist should always measure an excision and document it with a statement, such as, "I’m going to excise this X cm length by X width lesion. I took 4 cm margins."

Reminder: If documentation indicates the margin is applicable to both sides of the lesion, double that measurement. For instance, taking a 4 mm margin on each side of the lesion equals a total of 8 reportable mm in addition to the diameter of the lesion itself.

The impact: If your dermatologist doesn’t put the original size in the note, you have to code based on the smaller excision size listed in the pathology report, which could cost your practice over $20 per excision.

Example: The dermatologist’s documentation states that he excised a lesion 1.0 cm length by 2.0 cm width with 0.2 cm margins. The pathology report comes back benign. You would report 11403 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere], trunk, arms or legs; excised diameter 2.1 to 3.0 cm) for the 2.4 cm codeable size ([2.0 lesion diameter] + [0.2 x 2 margins]). If, however, the physician had failed to document the size and the pathology report measured a 1.0 cm lesion plus 0.1 margins, you could code only 11402 (… excised diameter 1.1 to 2.0 cm), resulting in a loss of $24 (Code 11403 has 5.39 nonfacility total relative value units [RVUs] compared to 11402, which the 2011 Medicare Physician Fee Schedule assigns 4.69 RVUs).

Important: You do need the pathology report to choose a code, but not for the size of the excision. You should always choose the malignant or benign excision code based on the results of the pathology report even if the physician did not know at the excision time that the lesion was malignant. The pathology report offers the definitive diagnosis that serves as the basis for the CPT^® excision code selection. A physician might sometimes visually identify a lesion as benign or malignant, but you still want to code the excision based on the pathology report.