Skin Neoplasm Codes

By Trina Cuppett, CPC, CPC-H and G. John Verhovshek, MA, CPC

Coding skin neoplasm diagnoses and excisions requires careful attention to detail. The key to accurate reporting is knowing the sort of detail to look for and where to find it. The following basic guidelines will set you on the right path.

Diagnosis Reporting: Let Path Report Guide You

The number one rule of neoplasm coding is, “report only what documentation confirms.” Coding a neoplasm diagnosis requires a pathology report—even if the physician knows what kind of neoplasm it is without one. There is one exception to this rule: If a lesion is destroyed with lasers, chemicals, or other methods (such as cryosurgery), a pathology report will not be ordered and the physician’s documentation may be used.

The ICD-9-CM Official Coding Guidelines, chapter 2: Neoplasms (140-239), explain: “To properly code a neoplasm it is necessary to determine from the record [specifically, the pathology report] if the neoplasm is benign, in-situ, malignant, or of uncertain histologic behavior. If malignant, any secondary (metastatic) sites should also be determined.”

ICD-9-CM describes a malignant neoplasm as one of three types (each of which may be reported using a different code):

  • A primary malignancy is the area (site) where a cancer begins to grow.
  • A secondary malignancy is one that has spread from the primary site to other parts of the body (for instance, primary lung cancer may spread to bone, and the secondary cancer in the bone will be made up of lung cells).
  • An in-situ malignancy is confined to its site of origin. These are early-stage tumors that may, however, evolve into invasive malignancies.

Neoplasms not indentified specifically as malignant may be benign (free of cancer) or of uncertain behavior (for instance, showing indications of atypia or dysplasia). Uncertain behavior does not indicate “unknown” or “unspecified;” an uncertain (or benign) designation must be supported by histologic examination. When a pathology report is not available to confirm the diagnosis, however, the neoplasm must be coded as unspecified.

Neoplasm Table, Tabular Index Confirms Coding

After you abstract the key information from the pathology report, turn to the Neoplasm table within the index (Volume 2 of the ICD-9-CM manual) to find the appropriate diagnosis. Codes are arranged alphabetically by site, with separate columns for each neoplasm type (primary, secondary, benign, etc.).

ICD-9-CM Official Coding Guidelines instruct, “The neoplasm table in the Alphabetic Index should be referenced first. However, if the histological term is documented, that term should be referenced first, rather than going immediately to the Neoplasm Table, in order to determine which column in the Neoplasm Table is appropriate.”

Important: For neoplasms that occur on or near the skin of an anatomic site, assign a diagnosis for skin rather than for the body area in question (for instance, “skin of hand” rather than “hand”). In every case, verify the selected diagnosis by checking the tabular list (Volume 1) of ICD-9-CM before assigning a final code. The ICD-9-CM Official Coding Guidelines stress, “The tabular should … be referenced to verify that the correct code has been selected from the table and that a more specific site code does not exist.”

As an example, the physician removes a suspicious mole from the patient’s earlobe. The lesion measures 2 cm. The pathology report reveals that the specimen shows an atypical lesion. To find the diagnosis, go to the neoplasm table and look for “neoplasm of connective tissue, ear (external).” Look in the Uncertain Behavior column to arrive at a provisional diagnosis of 238.1. The tabular list confirms that this diagnosis applies to “Neoplasm of uncertain behavior of other and unspecified sites and tissues; connective and other soft tissue.”

Procedure Reporting: Type, Location, and Size Determine Coding

CPT® provides different code sets to report excision of benign (11400-11471) and malignant (11600-11646) skin lesions/neoplasms. The codes within each set are differentiated broadly by site (for example, trunk and arms or legs vs. scalp, neck, hands, feet, and genitalia). A quick review is all you need to familiarize yourself with the code organization. Be sure to read the CPT® guidelines in the section carefully.

Most important: Accurate lesion and margin measurements allow for complete and appropriate coding.

CPT® instructions define the excised lesion diameter as the “greatest clinical diameter of the apparent lesion plus that margin required for complete excision.” This is equal to the greatest lesion size, plus twice the size of the narrowest margin (the length of the incision used to remove the lesion is not a factor). Note: Base your coding on measurements documented prior to excision (rather than taken from the pathology report, for instance).

For example, a physician removes a lesion from a patient’s nose along the supra-alar crease. The lesion measures at 1.5 cm at its widest point and there is an allowance of 1.0 cm margin on all sides. The pathology report later confirms the lesion as benign.

To calculate, consider the narrowest margin (1.0 cm) x 2 = 2 cm. Add this figure to the widest measurement of the lesion (1.5 cm) for a 3.5 cm total. Based on the location of the lesion (nose) and the total measurement (3.5 cm), the correct code is 11444 Excision, other benign lesion including margins, except skin tag (unless listed elsewhere), face, ears, eyelids, nose, lips, mucous membrane; excised diameter 3.1 to 4.0 cm.

CPT® codes are based on centimeters, so if the physician reports the lesion’s diameter in millimeters, you must convert the measurements (for instance, 1 mm = 0.1 cm). Please notice that some codes are reported in centimeters and others are in square centimeter measurements (0.16 sq in = 1 sq cm).

Note: There are plenty of websites (such as that allow you to easily perform these mathematical conversions online.

For example, if a physician documents a benign lesion excision of the upper arm that is 5 mm in diameter (including margins), this converts to 0.5 cm for CPT® coding accuracy and is 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.


Treat Each Lesion Separately

Benign and malignant lesions should be coded separately. Do not add together the excised diameters of multiple lesions as you would the lengths of multiple wounds for wound repair (12001-13160). When reporting multiple excisions, link a separate diagnosis (supported by a pathology report) to each CPT® code. Append modifier 51 Multiple procedures to the second and subsequent excision codes (for those payers who accept the codes) at the same location.

For example, a physician removes three lesions from a patient’s left shoulder with the following measurements: 2.5 cm (malignant), 1.5 cm (malignant) and 4.1 cm (malignant).

In the CPT® index look up “Excision, Skin, Malignant,” which points to the code range 11600-11646. Then, code according to the documented size of the lesions:

  • 11606 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter over 4.0 cm
  • 11603-51 Excision, malignant lesion including margins, trunk, arms, or legs excised diameter 2.1 to 3.0 cm
  • 11602-51 Excision, malignant lesion including margins, trunk, arms, or legs excised diameter 1.1 to 2.0 cm

Understanding CPT® and ICD-9-CM coding guidelines for neoplasms is crucial to building your confidence as a coder, and to assuring that you are coding with efficiency and accuracy.

Trina Cuppett, CPC, CPC-H, has an associate degree in paralegal technology, which allows her to combine her passion for coding and compliance. She has four years experience as an instructor and is currently in the process of forming a consulting business. Tina has been an AAPC National Advisory Board (NAB) member since 2009.


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