Measuring Skin Lesions
CPT(R) provides different code sets to report excision of benign (11400-11471) and malignant (11600-11646) skin lesions/ neoplasms.
The codes for Measuring Skin Lesions within each set are differentiated by site:
? Trunk and arms or legs
? Scalp, neck, hands, feet, and genitalia.
The important factors out of these are accurate lesion and margin measurements to allow for complete and appropriate coding.
CPT(R) instructions define the excised diameter of a lesion as the ?greatest clinical diameter of the apparent lesion plus that margin required for complete excision.?
Specifically, this is equal to the greatest size of the lesion, plus twice the size of the narrowest margin (the length of the incision used to remove the lesion is not a factor). Note that coding should be based on measurements documented prior to excision rather than taken from the pathology report, for instance).
Note that CPT(R) codes are based on centimeters. Therefore, if the physician reports the diameter of the lesion in millimeters, the coder must convert the measurements (for instance, 1 mm = 0.1 cm). It should be noted that some codes are reported in centimeters and others are in ?square? centimeter measurements (0.16 sq in = 1 sq cm).
For example, if the physician has documented that he excised a benign lesion of the upper arm that is 4 mm in diameter (including margins), this would convert to 0.4 cm for CPT(R) coding accuracy and would be reported with 11400 Excision, benign lesion including margins, except skin tag (unless listed elsewhere), trunk, arms or legs; excised diameter 0.5 cm or less.