Excision of Skin Lesions: Coding Guidelines

Jun 18, 2024
5 min read
Abhaya Prabhu, Sivakumar Mani, Havila Deepti
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Objective: 

This article aims to guide healthcare professionals, providers, coders, and payers in accurately coding skin lesion excisions by clarifying the essential parameters that determine code selection. It will break down the process of determining these parameters and their impact on code selection, ultimately helping all to navigate the complexities of skin lesion excision coding easily.

Skin and Skin Lesion: 

The skin, the largest organ of the human body, is much more than just a protective layer. Often referred to as the integument, it acts as our guardian against the external world, shielding our internal organs from harmful elements. But the skin's role extends far beyond mere protection. Additionally, the skin functions as a complex sensory organ, enabling us to feel touch, heat, and cold.

Location-Specific Coding: 

Accurate reporting of skin lesion excisions is essential for proper reimbursement and medical documentation. Each excision must be reported separately based on the lesion's anatomical location, whether benign or malignant. The following table provides a general overview of the coding structure for skin lesion excisions based on location.

Multiple lesions in the same or different locations have to be coded based on the site, type, size, and procedure. Let’s look at certain scenarios to better understand them.

Scenario 1: Multiple Lesions in Different Sites

  • Code each lesion separately based on size, location, and type.
  • List procedures in descending order of Relative Value Units (RVU). The procedure with the highest RVU is listed first.
  • Append modifier 59 to the second and subsequent codes.

Scenario 2: Multiple Lesions of the Same Size in the Same Site

  • Code each lesion separately with the same CPT code.
  • Append modifier 59 to each code after the first.

Scenario 3: Multiple Lesions of Different Sizes, Same Site

  • Code each lesion separately based on size, location, and type.
  • List procedures in descending order of RVU (highest first).
  • Append modifier 59 to the second and subsequent codes.

Size Determination: 

For excision diameter: Measure the widest part of the visible lesion. Determine the narrowest margin needed for complete removal. This is a clinical judgment based on factors like the type of lesion (benign vs. malignant) and its location. Add the lesion diameter and twice the narrowest margin to find the excised diameter. 

Lesion Procedures Codes: 

Skin lesion procedures are a common medical practice involving the removal of various skin growths or abnormalities. Coding the procedure accurately is essential for proper documentation, reimbursement, and statistical analysis. Here's an explanation of the coding process:

Types of Skin Lesion Procedures:

  • Excision: Complete removal of the lesion and surrounding margin of healthy tissue. This is the most common procedure for suspicious or cancerous lesions.  Simple repair is performed for uncomplicated wounds after excision of a skin lesion. It is important to note that simple repairs are considered an integral part of the excision procedure and are not coded separately.
  • Shaving: Shaving involves the removal of epidermal and dermal skin lesions with transverse incision or horizontal slicing.
  • Destruction: Elimination of the lesion through methods like electrocautery, cryosurgery, or laser therapy. Often used for precancerous or small benign lesions.
  • Biopsy: A biopsy is a diagnostic procedure primarily performed to determine the nature of a skin lesion. A sample of tissue is removed from the suspicious area and sent for histopathological analysis. While the biopsy is mainly a diagnostic tool, it can also have therapeutic benefits. In certain cases, a biopsy may remove the entire lesion, effectively treating the condition. However, the primary purpose of a biopsy remains the definitive diagnosis of the lesion, guiding further treatment decisions and management strategies.

General Guidelines for Coding Skin Lesion Excision: 

Accurate medical billing for skin lesion excisions relies on selecting the appropriate CPT (Current Procedural Terminology) code, which is determined by several key factors:

1. Excision of Skin Origin Tumors: The excision of subcutaneous tumors involves removing a typically benign tumor within the fatty layer beneath the skin without extending into deeper tissue. The exception is melanoma and other malignancies of skin origin that are spread to deeper tissues. Such cases are coded with skin and subcutaneous series ranging from 11600-11646 of codes series rather than the musculoskeletal series. 

2. Re-Excision :

  1. Same Operative Session: If additional excisions or re-excisions are performed during the same operative session to achieve complete tumor removal, use only one code based on the final widest excised diameter.
  2. Different Operative Session: For re-excisions performed in a subsequent operative session to widen margins, refer to codes 11600-11646, as appropriate.
  3. During Postoperative Period: When a re-excision is performed during the postoperative period of the primary excision, append modifier 58 to the appropriate code (11600-11646).

3. Pathology Report: The final diagnosis will be established based on the pathology report, which in turn decides which series, whether benign or malignant, needs to be coded.

4. Simple repairs are included in excision, while complex and intermediate repairs need to be coded separately if done. 

5. Whenever Adjacent Tissue Transfer (ATT) is performed, excision should not be coded separately. 

By following these guidelines and carefully documenting the lesion size, location, margins, and pathology results, healthcare providers can ensure accurate coding for skin lesion excisions, leading to proper reimbursement and compliance with medical billing regulations.

Ease your way into the skin lesion coding guidelines… Stay tuned to more articles from CoverSelf! 

Reference: 

  1. https://www.aapc.com/blog/26192-skin-lesion-excision/
  2. AMA CPT Manual