Biopsy, shave, or excision?

Cracking the Code

Alexander Miller

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

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You evaluate a patient’s clinically atypical arm mole and decide that it merits a biopsy, which you do via saucerizing (deep shaving) the lesion with a narrow surrounding rim of clinically mole-free skin. In the process of doing the biopsy you penetrate into the subcutaneous fat, removing the lesion along with a thin underlying rim of fat. The subsequent histopathology reveals a malignant melanoma, with the tissue removal extending into the subcutaneous fat and narrowly clear margins. You hold billing for the procedure until the histopathologic diagnosis is established. Do you then bill for a skin biopsy, a shave removal of the lesion, or for an excision?

The answer to the above question requires an interplay of several criteria, including the physician’s intent, the supporting documentation of what was done, and personal ethical considerations. The criterion for a biopsy is satisfied by intent. The CPT defines a biopsy as a “procedure to obtain tissue for a pathologic examination.” It does not specify what kind of procedure that can be. Consequently, biopsy codes 11100 and 11101 stipulate skin, subcutaneous, or mucosal tissue sampling via the means of your choice, including scissors removal, sharp blade tangential or saucerize extraction, punch sampling into the subcutaneous fat, or sampling via scalpel incision penetrating into or through the skin to any level, including into the subcutaneous fat. If the physician’s intent is to sample tissue for the purpose of a histopathologic diagnosis, then a biopsy is done. [pagebreak]

Shave codes (CPT 11300 11313) are appropriate when a portion of or an entire cutaneous lesion is tangentially or saucerize removed with a sharp blade, with the depth of the removal extending no deeper than into the dermis. These codes, unlike the biopsy codes, are limited to use for skin only. The CPT recognizes that the shaved tissue may be submitted for histopathologic examination. However, the CPT does not expressly indicate whether the shave series of codes is to be used only in situations where histopathologic examination of the removed tissue is incidental to the procedure, or whether the codes may be used when the intent is to obtain tissue specifically for diagnostic histopathology as well as to remove the lesion. However, the October 2004 CPT Assistant further clarifies: “The intent of a biopsy is to remove a portion of skin, suspect lesion, or entire lesion so that it can be examined pathologically.” If you remove tissue because you want to find out what it is, then the removal constitutes a biopsy, CPT 11100 or 11101. If a portion of skin is tangentially removed for cosmetic, functional, or comfort considerations, and histopathologic examination is done incidental to the removal, the shave codes are most appropriate. Note that the shave codes include the removal of both benign as well as malignant lesions. The spring 2011 Derm Coding Consult further discusses the biopsy versus shave removal conundrum.

The CPT distinguishes a simple excision (codes 11400 11646) from a biopsy or shave via two criteria:

  1. The excised lesion must be removed through the dermis (i.e., into subcutaneous tissue).
  2. The excision includes margins.

There is no mention as to the intent of the excision. The October 2004 CPT Assistant further clarifies: “The intent of an excision procedure is to remove the entire lesion along with a margin of normal tissue around it.” Thus, an excision may be billed for diagnostic, therapeutic, cosmetic, and any other situations where a skin lesion is excised into the subcutaneous tissue. [pagebreak]

Lastly, per CPT, a simple excision includes a non-layered closure when performed. Simple suturing is included in the code but is not required for its proper use. Note that “non-layered closure” does not indicate which layer is closed. As long as only one suturing layer is done at any depth, whether cutaneous or subcutaneous, a simple excision code is to be billed.

Now, let’s return to the clinical scenario at the top of this article. A mole subsequently shown to be a melanoma was removed with margins, into the subcutaneous fat, for the purpose of histopathologic diagnosis. Immediately, a shave code is ruled out, as the removal was done through the dermis. However, was a biopsy or an excision done? The answer: by CPT definition, both were done. The intent was to do a diagnostic sampling biopsy, so that satisfies the biopsy definition. Incidental to the biopsy the tissue was removed through the dermis, with margins. Consequently, a malignant excision code is also justified by CPT definition. You are left with a quandary and a choice: bill an 11100 biopsy code or a malignant excision (11600 series). Clearly, the malignant excision code is reimbursed at a higher level than a biopsy code. How should you bill? That will be your personal ethical choice. [pagebreak]

Example 1: You suspect a squamous cell carcinoma on a patient’s chest. Wanting to confirm your suspicion, you remove the lesion through the deep dermis via the saucerization technique, 1.5 cm diameter, and hold billing for the procedure until the histopathologic diagnosis is received. The histopathology confirms the presence of a well-differentiated squamous cell carcinoma extending into the mid dermis, with peripheral and deep margins clear. Since the histopathology showed that you removed the lesion in its entirety, with margins, you bill for an excision of a malignant lesion, CPT 11602.

Answer: Incorrect. Per the CPT definition, in order to qualify as an excision tissue removal has to be done through the dermis, which means all the way through and into subcutaneous tissue. The intent was to both biopsy and remove the lesion. Consequently, either biopsy, 11100, or shave removal, 11302, are reasonable to use. [pagebreak]

Example 2: You do a deep shave removal of a glabrous lip papulonodule suspicious for a basal cell carcinoma. The histopathology confirms skin tissue with a narrow deep base of subcutaneous fat and muscle, and a central basal cell carcinoma, margins clear. As you removed this 0.8 cm diameter tissue with the shave technique, you bill CPT 11311, shave removal.

Answer: Incorrect. Although the technique was that of a shave removal, the end result was a tissue removal through the dermis, with margins, into subcutaneous tissue. Since the shave series of codes are limited to removals through the epidermis or dermis, but no deeper, they are inappropriate. The optimal code is a malignant excision, CPT 11641.

Example 3: You biopsy a suspected basal cell carcinoma located on the neck with a 6 mm punch, penetrating into the subcutaneous fat. The histopathology confirms a basal cell carcinoma with narrowly clear margins. You then bill for a malignant excision, CPT 11621.

Answer: Correct. The procedure done was, by definition, an excision, as it encompassed full-thickness through the dermis removal of the lesion. Although a malignant excision code may be used, it is also appropriate to use a biopsy code, 11100, as the original intent was to obtain tissue for histopathologic diagnosis.