Overview

Background

Definitions

• Wound biopsy: wound biopsy is a procedure to obtain tissue (often skin) from the wound for diagnostic histopathological examination and/or culture and susceptibility studies (C&S).

Types of skin biopsy

According to the American Medical Association Current Procedural Terminology (AMA CPT) Codebook guidelines, there are three distinct techniques for skin biopsies: tangential, punch and incisional biopsies.[5][6] 

• Tangential biopsy (CPT codes 11102–11103): tangential biopsy is a skin biopsy performed with a sharp blade, such as a flexible biopsy blade, obliquely oriented scalpel or curette to remove a sample of epidermal tissue with or without portions of underlying dermis (Figure 1). These are not considered excisional biopsies, which remove the entire lesion with margins. Tangential biopsy technique may be represented by a superficial sample and does not involve the full thickness of the dermis, which could result in portions of the lesion remaining in the deeper layers of the dermis.[5]
• Punch biopsy (CPT codes 11104–11105): a punch biopsy uses a punch tool to remove a full-thickness cylindrical sample of the skin (Figure 2). Simple closure of the defect is included in the service. Manipulation of the biopsy defect to improve wound approximation is included in simple closure. For a video and protocol on how to collect a punch biopsy, see sections 'Procedure: Punch Biopsy of a Wound' and 'Video'.
• Incisional biopsy (CPT codes 11106–11107): an incisional biopsy requires use of a sharp blade to remove a full-thickness sample of tissue via a vertical incision or wedge, penetrating deep to the dermis and into the subcutaneous space (Figure 3). This method may sample subcutaneous fat. Although closure is usually performed on incisional biopsies, simple closure is not separately reported.

Of note, the AMA CPT Codebook also lists shaving of epidermal/dermal lesions and excision of lesions. For these procedures, the removed tissue may be submitted for histopathological analysis however the primary intent is to remove the lesions and not to collect a specimen for diagnostic histopathologic examination like the biopsy codes above.  

• Shaving of epidermal or dermal lesions (CPT 11300-11313): shaving is the sharp removal by transverse incision or horizontal slicing to remove epidermal and dermal lesions without a full-thickness dermal excision. This includes local anesthesia, chemical or electrocauterization of the wound. The wound does not require suture closure.
• Excision of lesion (CPT 11400 and 11600 series): excision is defined as full-thickness (through the dermis) removal of a lesion (benign or malignant), including margins, and includes simple (non-layered) closure when performed. 

Types of bone biopsy

The AMA CPT Codebook guidelines list two methods for bone biopsy that are more likely to be utilized by wound care clinicians [5]:

• Biopsy with a trocar, or needle (codes 20220 and 20225)
• Open biopsy (codes 20240 and 20245)

Types of InvestigationS

• Histopathology: histopathology is the diagnosis and study of diseases of the tissues. It involves interpretation of the skin under the microscope, generally employing hematoxylin and eosin (H&E) staining. It is the main study of skin biopsy and helpful in inflammatory, neoplastic and structural pathology.[2]
• Direct immunofluorescence: direct immunofluorescence involves the application of fluorophore-antibody complexes, which bind to specific antigens present within specific dermatoses. It is useful in detecting selected autoimmune blistering diseases, vasculitis, and genetic diseases that are expressed as skin conditions (genodermatoses).[2]
  
• Wound culture: wound cultures are laboratory tests to determine the type and quantity of microorganisms in a wound. To perform a wound culture, a sample of tissue or fluid taken from the wound bed and placed in a sterile container for transportation to the laboratory. In the laboratory, the sample is placed in a substance that promotes growth of organisms and the type and quantity of organisms that grow are assessed by microscopy.[7]  For details, see topic "Wound Culture - Swabs, Biopsies, Needle Aspiration".
• Susceptibility study: if upon wound culture pathogenic microorganisms are identified, a susceptibility study is performed at the laboratory by growing the pure bacterial isolate in the presence of varying concentrations of several antimicrobials and then examining the amount of growth to determine which antimicrobials at which concentrations inhibit the growth of the bacteria.[8] For details, see topic "Wound Culture - Swabs, Biopsies, Needle Aspiration".

Common types of specimen transport medium

• 10% buffered formalin: formalin is the saturated form of formaldehyde in water. It is both a fixative and a transport medium for transport of tissue to be analyzed for histopathology (e.g. H&E and other stains).
• Normal saline: saline is commonly used to transport tissue samples for bacterial or fungal tissue cultures. Viral cultures require a special viral transport media.[1] 
• Michel's medium: Michel's medium is a transport medium for direct immunofluorescence.[9]
• Glutaraldehyde: used for specimens for electron microscopy.[1] 
  

Care Setting

• Wound skin biopsies may be performed in several care settings including inpatient hospital, outpatient hospital, home health, skilled nursing facilities, provider's office, and others.
  

Scope of Practice for Collection of a Wound Biopsy Specimen

• Performing a wound biopsy is within the scope of several healthcare professionals including physicians, nurse practitioners, and physician assistants. In the U.S., nurses may be allowed to perform a punch or tangential skin biopsy, depending on each state's laws and regulations, local policies, and if other requirements are met (e.g. an order from a qualified healthcare provider/ licensed independent practitioner is present, size, location, patient age and risk profile).
• In the United States, an order should be obtained for diagnostic tests from the treating physician/nonphysician practitioner (as required by CFR, Title 42, Volume 2, Chapter IV, Part 410.32(a) Ordering diagnostic tests).[10]

WHEN TO PERFORM A WOUND BIOPSY

General Indications and Contraindications

Indications

Consider performing a wound biopsy for wounds present for more than 3 months, especially wounds that have not responded to the treatment of the suspected cause.[1] Wound biopsies are performed in order to [1]:

• Diagnose the etiology of a wound
• Rule out malignancy 
• Obtain tissue for bacterial quantitative culture 

Contraindications

Relative contraindications to wound biopsy include [1][4]: 

• Blood disorders with the risk of uncontrollable bleeding 
• Venous congestion and vascular wounds (e.g. arterial insufficiency) in a setting where resources are limited 

HOW TO PERFORM A WOUND BIOPSY

Assessment

• Prior to performing a biopsy on a chronic wound, it is important that a comprehensive assessment be performed. See topics "How to Assess a Patient with Chronic Wounds" and "How to Determine Healability of a Chronic Wound".
• Specific attention should be given to [1]:
• Allergies, including those to topical antibiotics, antiseptics, local anesthetics, and tape or adhesives.
• Increased risk of bleeding during the procedure: 
• Known bleeding disorders or previous history of excessive bleeding related to surgery or trauma: an electrocautery may be needed and/or sutures may be required after the specimen is removed to stop the bleeding.
• Medications that interfere with hemostasis (e.g., warfarin): patients should hold the medication on the day of or for a few days prior to the procedure.
• Smoking and use of corticosteroids have been associated with higher risk of local post-biopsy infection.[4] 

Selection of the Biopsy Site, Technique and Transport Medium

Choosing the site, technique and transport for a skin biopsy is an important decision. In the process of planning biopsies, early involvement of your laboratory including pathology and microbiology is important so that the appropriate transport media can be immediately available. Optimal site, type of biopsy and transport medium for different conditions are summarized below and in Algorithm 1. [1][2]

• The biopsy specimen should include epidermis, dermis and subcutaneous tissue (except when the condition is confined to the epidermis and superficial dermis)
• For suspected cancerous lesions, the specimen should be taken from the wound edge via excisional biopsy or punch biopsy (if punch biopsy, multiple specimens may be needed) for H&E and for wound culture and susceptibilities (C&S) if signs of infection.
• For autoimmune vesicles, bulla, and pustules, the specimen should be taken via punch biopsy from the edge of a recent lesion (< 24h) for H&E and for C&S if signs of infection. Consider obtaining a specimen from normal-looking periwound for direct immunofluorescence. 
• For vasculitis (small vessel), obtain a wound edge specimen from a 24-48h old lesion for H&E via punch biopsy, and a wound edge or periwound specimen from a new lesion (< 24h old) for direct immunofluorescence via punch biopsy. See topic "Cutaneous Vasculitis".
  
• For pyoderma gangrenosum, obtain a wound edge specimen from a recent lesion for H&E via incisional biopsy (preferable) or punch biopsy. Direct immunofluorescence findings are neither sensitive nor specific for pyoderma gangrenosum. Thus, it is suggested that direct immunofluorescence be conducted when additional findings require exclusion of immuno-bullous disease, lupus, or vasculitis as potential causes of cutaneous ulceration.[11] See topic " Pyoderma Gangrenosum - Introduction and Assessment".
• For infective ulcers, obtain a specimen from the center of the wound for C&S and H&E. For details on C&S, see topic "Wound Culture - Swabs, Biopsies, Needle Aspiration".

Procedure: Punch Biopsy of a Wound

After determining that a skin biopsy is indicated, clinicians may utilize the following steps shown in Tables 1-3 as a guide for performing a punch biopsy.[1][2]

Table 1. Pre-procedure

Table 2. Procedure:

Table 3. Post-procedure

Documentation

Documentation should include:

• Wound assessment and characteristics, rationale for a biopsy (e.g. delayed wound healing despite adequate care, etc), purpose of the procedure (e.g. histopathological analysis)
• Documentation of the procedure: method, number of units, location, specimen removed (full-thickness, partial thickness).[6]
• Sampling of stratum corneum only, by any modality (eg, skin scraping, tape stripping) does not constitute a skin biopsy procedure and is not separately reportable.[5]
• Dermatopathology requisition form, microbiology request if submitting specimen for C&S. See topic "Wound Culture - Swabs, Biopsies, Needle Aspiration".

Video

Video 1. Punch biopsy on an atypical wound. By Scott Robinson, MD

CODING, COVERAGE, REIMBURSEMENT

Medicare Administrative Contractors and Local Coverage Determinations

Medicare coverage of provider and facility fees related to wound cultures is managed by Medicare Administrative Contractors (MAC), under Medicare Part A or Part B. Each jurisdiction may have its own specific local coverage determination and policies. See topic "Medicare Coverage Determinations for Wound Care".

CPT codes

Biopsy of Skin

• A specimen can be divided and sent for C&S and histopathological analysis. For a skin biopsy CPT to be used, the specimen needs to be sent for histopathological analysis. 
• Biopsy of the skin is reported under three distinct techniques: tangential, punch, or incisional.[5]
• See CPT codes for skin and bone biopsies in the Appendix - CPT Codes.

Coding Tips

The use of a biopsy procedure code (eg, 11102, 11103, 11104, 11105, 11106, 11107) indicates that the procedure to obtain tissue solely for diagnostic histopathologic examination was performed independently, or was unrelated or distinct from other procedures/services provided at that time.[5]

Multiple Skin Biopsies On The Same Date

• When multiple biopsies are performed for the same patient on the same date, only one primary biopsy code may be reported, depending on the following [5][6]:
• If multiple biopsies are performed using the same technique, report the primary code (11102, 11104, 11106), then use the corresponding add-on code for the other biopsies.
• For instance, if an incisional biopsy is performed, report 11106 in combination with a tangential (11103), punch (11105), or incisional biopsy (11107) for the additional biopsy procedures.
• If multiple biopsies are performed using different techniques, report the primary code (11102, 11104, 11106), then use the add-on code that is specific to the other biopsies performed.
• When billing for these services, record the method and the number of units in your documentation. Although the location of the biopsy is not required to select a code, it should be document as well. An example of coding for multiple biopsies is shown in Table 4 below.

Table 4. Sample coding for multiple skin biopsies performed on the same date

Skin Biopsy and Evaluation and Management (E/M) Services On The Same Date

• Do not report E/M level if the sole reason for the scheduled visit is to undergo a diagnostic or therapeutic test/service procedure. For further details see section 'Billing for evaluation and management and procedures on the same day' in topic "Coding and Billing Essentials in Wound Care" 
• Payment for diagnostic (with the exception of pathology and laboratory) and/or therapeutic procedure(s) (code ranges 10040-69990, 70010-79999 and 90281-99140) already includes taking the patient’s blood pressure, temperature, asking the patient how he/she feels and getting the consent form signed. Since payment for these types of services is already included in the payment for the procedure, it is not appropriate to bill for an E/M service separately. 
  
• However, there are circumstances when it is appropriate to report an E/M service code in addition to the procedures provided on the same date, provided the patient’s condition required a significant separately identifiable E/M service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. 
• Should a separately identifiable E/M service be provided on the same date that a diagnostic and/or therapeutic procedure(s) is performed, information substantiating the E/M service must be clearly documented in the patient’s medical record, to justify use of the modifier –25. 
• The Current Procedural Terminology (CPT-4) manual gives the definition of modifier -25 as follows: “Significant, Separately Identifiable Evaluation and Management Service by the Same Physician on the Same Day of the Procedure or Other Service.”
  
• Example: a wound provider examines an established patient during a regularly scheduled follow up for a diabetic foot ulcer. During the patient’s exam, a new suspicious skin lesion on the leg is discovered. The physician determines this should be biopsied and performs a punch biopsy. In this scenario, the E/M would qualify as a separately identifiable service from the procedure of the biopsy. Report appropriate level E/M code with modifier 25 and procedure code (99213-25, 11100).

Multiple Procedures On The Same Date

• If two procedures are performed for the same condition on the same date, check the National Correct Coding Initiative (NCCI) edits and report only the one that is reportable per NCCI edits. See section 'National Correct Coding Initiative Edits (NCCI)' in topic "Coding and Billing Essentials in Wound Care".
• MACs implemented NCCI PTP edits within their claim processing systems and CMS incorporated PTP edits into the outpatient code editor (OCE) for OPPS. These edits are applied to outpatient hospital services and other facility services including, but not limited to, therapy providers (Part B Skilled nursing facilities (SNFs)), comprehensive outpatient rehabilitation facilities (CORFs), outpatient physical therapy and speech-language pathology providers (OPTs), and certain claims for home health agencies (HHAs) billing under TOBs 22X, 23X, 75X, 74X, 34X. [12]
  

APPENDIX