Malignant destruction coding
Malignant destruction coding

Cracking the Code

Alexander Miller

Dr. Miller, who is in private practice in Yorba Linda, Calif., represents the American Academy of Dermatology on the AMA-CPT Advisory Committee.

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You obliterate a basal cell carcinoma on the back by curetting and electrodesiccating the tumor site twice. The initial curetting expands the treated diameter to one wider than that of the clinically visible lesion. The electrodesiccating shrinks the diameter somewhat, and the subsequent second curetting again expands the diameter, followed by another slight shrinkage upon electrodesiccation. Which of the generated diameters should be used for properly determining the appropriate CPT malignant destruction code (17260 – 17286)?

The CPT specifies that the destruction may be done by any of a variety of methods, including electrosurgery (electrodesiccation or electrofulguration), cryosurgery (liquid nitrogen freeze), or laser or chemical techniques, with or without a curetting. Thus, any of the aforementioned destructive modalities used singly or in any combination for treating a lesion will constitute a single destruction. The malignant destruction code series (17260 – 17286) in the CPT lists the anatomic location and “lesion diameter” as the determinants for proper code selection. Clinicians appreciate that many malignant lesions will curette to a diameter wider than the initial surface visible size. The CPT does not provide specific instructions as to which treatment stage determines the “lesion diameter.” Is it the initial visible maximum diameter of the lesion? Is it the diameter after the first or second curetting? Or is it the diameter after electrodesiccation?

A review of publications and discussions on how to best determine lesion diameter made it clear that there is no consensus on how this should be done. It seems best to concentrate, from the coding standpoint, on what is desired: a true measurement of the lesion’s diameter. Although the preoperative visible lesion size may be used for this determination, it does not always represent the true diameter. A curetting may reveal a broader and deeper subclinical spread. Occasionally, a second curetting, done after electrodesiccation, will further extirpate a focus of friable tumor, thereby expanding the lesion diameter. The goal is to truthfully provide what you, the treating medical professional, perceive as the actual maximum diameter of the lesion. This may be an initial measurement prior to treatment, it may be the size after one curetting, or it may be the diameter after more than one curetting. [pagebreak]

The CPT stratifies lesion diameter coding into niches of size ranges (to 0.5 cm, 0.6 to 1.0 cm, 1.1 to 2.0 cm, etc.). Once the lesion’s location is determined, then the task is to fit its diameter measurement into the appropriate size range to select the proper CPT code. Simple: provide an honest measurement and fit it to the appropriate size range. Record how the diameter reading was reached: via clinical size of the lesion, after curetting, or after complete destruction. It is best to document the initial measured diameter of the lesion prior to treatment and, if the diameter of the destruction is used for code selection, that measurement, as well. 

Example 1: A basal cell carcinoma on the back is measured as 1.2 cm in diameter on the skin surface. Following curetting it is no wider, but after electrodesiccation it has contracted to 1.0 cm. You bill CPT 17262 (lesion diameter 1.1 to 2.0 cm).

Answer: Correct. In this case, the curetted and the initial clinical diameter are the same and reflect one’s best assessment of the lesion’s diameter. The electrodesiccation generated a falsely reduced diameter, as it shrank the tissue borders prior to the measurement.

Example 2: You shave off a 0.5 cm wide lesion suspicious for a basal cell carcinoma on the neck. The maximum diameter of the shave is 0.8 cm. You await the histopathologic diagnosis prior to submitting your bill. The histopathology confirms the presence of a basal cell carcinoma with cut tissue edges free of tumor. As you apparently fully treated the tumor, you bill CPT 17271, malignant destruction on the neck (lesion diameter 0.6 to 1.0 cm).

Answer: Incorrect. Although the lesion was fully removed, the procedure done does not fit the destruction code definition. The CPT Assistant, August 2009 issue, p. 7, specifies that destruction is “…not removal by excision or shaving of skin lesions using surgical instruments such as a knife, scalpel, or other similar tools.” Consequently, the appropriate CPT code is either biopsy, 11100, or shaving of epidermal or dermal lesion, 11306.

Example 3: You remove a suspected 0.5 cm wide basal cell carcinoma on the cheek via the saucerize shave technique to a 0.7 cm diameter size, submit the specimen for histopathologic diagnosis, and immediately destroy the residual lesion by curetting and electrodesiccating the site to a 0.9 cm maximum diameter. You bill CPT 11000 for the biopsy and 17281 for the curetted lesion diameter of 0.9 cm.

Answer: Incorrect. In the above case the final, definitive, destruction procedure determines the code. Although the lesion was submitted for histopathologic evaluation, neither a 11100 biopsy nor a shave removal (11310) code is appropriate. One should code for the highest specificity of what was done. In this case, the final intent and procedure was to fully treat the lesion by destroying it. Consequently, the lesion removal is incidental to the destruction. Only the 17281 destruction code should be billed.