Skin lesion excision refers to the surgical procedure of removing a cancerous skin lesion and an area of surrounding tissue called the margin. Medical coding services for this biopsy excision involve assigning appropriate CPT codes for the procedure performed. To accurately code for the skin lesion excision, the documentation should include details such as – whether the lesion is benign or malignant, the location of the lesion and the excised diameter of the lesion.

Though lesion excision coding seem to be complex, reporting excision of benign (non-cancerous) and malignant (cancerous) skin lesions can be made easy with some steps such as the following.

Check pathology reports

Before assigning the codes, check the pathology reports to confirm whether the neoplasm is benign, in-situ, malignant, or of uncertain histologic behavior. While benign lesions or one of uncertain behavior (indications of atypia or dysplasia) are reported using CPT codes 11400-11471, malignant skin lesions can be documented with codes ranging from 11600 to 11646. Malignancy may be primary (malignancy at the site where a cancer begins to grow), secondary (malignancy has spread from the primary site to other parts of the body), or in-situ (an early-stage tumor that may evolve into an invasive malignancy).

An AAPC article recommends coders to assign an unspecified diagnosis and a benign lesion excision CPT® code (11400-11471) if there is no pathology report available to confirm the diagnosis. However, if the provider performs a re-excision to obtain clear margins at a later operative session, report the same diagnosis as that used for the initial procedure.

Consider location

To assign the correct codes, it is important to know the anatomic location from which the lesion(s) is excised. It is recommended to group together multiple areas within a single set of codes. Site-specific classifications can be used to report each skin lesion excision independently as –

Benign lesion

  • Trunk, arms, legs – 11400-11406
  • Scalp, neck, hands feet, genitalia – 11420-11426
  • Face, ears, eyelids, nose, lips, mucous membrane – 11440-11446

Malignant lesion

  • Trunk, arms, legs – 11600-11606
  • Scalp, neck, hands, feet, genitalia – 11620-11626
  • Face, ears, eyelids (skin only), nose ,lips – 11640-11646

Size of lesion and margin matters

The size of lesion as well as margin (the area surrounding the lesion that is also removed) is of great importance when reporting skin lesion excision. Physicians should document the measurement of the lesion plus margin before the excision. Coders can use the greatest measurement of the diameter (distance across the lesion) and add to that the margin required for complete excision (determined by the physician). If the physician does not document a margin, it is advised to use the greatest measurement given. According to CPT® instructions, “Code selection is determined by measuring the greatest clinical diameter of the apparent lesion plus that [most narrow] margin required for complete excision.”

Make sure no codes are selected based on the size of the incision and/or the resulting surgical wound. Also remember that a coder should not make any assumptions about the size of the excision other than what is stated.

Simple repairs can be bundled with excision

Even if CPT® guidelines state that all lesion excision codes include simple wound closure, it allows separate coding for intermediate (12031-12057) and complex (13100-13153) repairs. But payers who follow National Correct Coding Initiative (NCCI) edits will bundle intermediate and complex repairs into excision of benign lesions of 0.5 cm or less (11400, 11420, and 11440).
When multiple lesions are removed by the surgeon, each will be treated as a separate procedure. Here add modifier 59, distinct procedural service to the second and subsequent codes for excisions in the same general location.

Coders should also pay careful attention to code descriptors. An example is discussed in AAPC’s blog session – if the surgeon removed a malignant lesion from a patient’s right shoulder and the lesion measured 1.0 cm at its widest prior to excision and the surgeon allowed a margin of at least 1.0 cm on all sides, for a total excised diameter of 3.0 cm (1.0 cm + [2 x 1.0 cm]), the correct code to use is “11603 Excision, malignant lesion including margins, trunk, arms, or legs; excised diameter 2.1 to 3.0 cm”.

Outsourcing medical coding is a practical solution for busy physicians. While outsourcing any such coding tasks, practices must choose professional medical billing and coding companies, as they can provide the services of experienced coding specialists.

Also read our blog on skin biopsy 2019 coding updates!