What Is Wrong-Site Surgery?

Wrong-site surgery (WSS) is defined as a “surgical or other invasive procedure performed on the wrong side, site, or patient, or an incorrect procedure performed on the patient.”1–6 WSS has received decades of national and international attention, yet it remains as a persistent, preventable medical error. Pennsylvania mandates that licensed healthcare facilities report patient safety events, ranging from near misses to events resulting in serious harm or death, to the Pennsylvania Patient Safety Reporting System (PA-PSRS).7 As a result, staff at the Patient Safety Authority (PSA) have a long history of using patient safety event reports to study WSS, among many other topics.

PA-PSRS Reports of Dermatologic WSS Events

Staff at PSA recently conducted a study of 664 WSS event reports, from a 10-year period, that were submitted to PA-PSRS.8 Within that study, there were 20 reports associated with the dermatology specialty; 15 occurred at a hospital and five occurred at an ambulatory surgical facility. Of the 20 dermatologic WSS events, 19 were wrong-site errors, one was a wrong-side error, and none were a wrong-procedure or wrong-patient error. The study also found that the procedures most frequently associated with WSS were the following: Mohs micrographic surgery (8 of 20), excision (5 of 20), biopsy (4 of 20), curettage (2 of 20), and laser procedure (1 of 20).

The top three body regions most frequently associated with dermatologic WSS events were head/neck, chest/thorax, and upper extremity. Within the head/neck body region, there was a range of specific body parts that were involved, such as scalp, forehead, eyelid, ear, cheek, and neck.

Dermatologic Risk Factors for and Strategies to Prevent WSS

A 2013 survey of 150 dermatologists within the United States identified WSS as the “most serious” practice error.9 Given the nature of dermatologic practice and findings from prior research,8 many, if not all, dermatologic procedures pose risk for WSS. As a result, both healthcare providers and patients have roles in preventing WSS, which should involve joint consensus, not sole assertion, when identifying the correct procedure site.10 The site should also be confirmed with use of objective documentation, especially photographs and landmark measurements, to reduce ambiguity.11–13 Reducing the risk of WSS requires a multistep approach involving physicians, their staff, and patients. Table 1 outlines risk factors for WSS in dermatologic procedures and strategies for prevention.

For more WSS findings and resources, see our article entitled “Wrong-Site Surgery: A Study of 664 Events From 237 Facilities Across a 10-Year Period” at doi.org/10.33940/001c.156001.

Table 1.Dermatologic Risk Factors for and Strategies to Prevent WSS.
Risk Factors for WSS in Dermatology
  • A time delay between the initial and final procedure may result in healed skin and a lack of a visible site. In particular, Mohs surgery for skin cancers is at higher risk for WSS because it is often performed several days to weeks after the initial diagnostic biopsy.13
  • Site identification is challenging when the patient has an underlying inflammatory skin disease, solar-damaged skin, other biopsy sites, or recently treated skin lesions in the immediate field (i.e., benign, precancers, or cancers).10
  • Inadequate documentation and office records (e.g., absent or poor-quality chart diagrams) may contribute to site misidentification.12,14
  • Photography concerns when documenting biopsy sites:
    • Absence of lesion photographs or low-quality photographs.10,15,16
    • The use of a patient’s own smartphone has been promoted to document biopsy sites; however, selfie photographs may produce mirror images, may not auto flip, and must be interpreted with caution.10,15,16
    • Some electronic health record software programs allow a user to flip photographs; therefore, users must be careful not to misorient photographs and must interpret them with caution.10,15,16
    • Photographic image editing software, including artificial intelligence tools, may auto enhance or modify photographs, which may lead to misidentification of the procedure site.10,15–17
Strategies to Prevent WSS in Dermatology
The following strategies for clinicians and staff are important throughout the continuum of care and are directly relevant to many dermatologic procedures.
  • Photographic documentation
    • Take photographs of the identified site for every procedure/surgery, including initial and follow-up procedures .11,16,18
    • Take more than one photograph of each procedure/biopsy site, including one showing the patient ID sticker, plus distant and close-up photos showing a ruler with triangulated measurements.10 Patients should temporarily remove face masks, which may hide anatomic landmarks.19
  • Other site identification strategies
    • Use specific and consistent anatomic designations and identifiers (e.g., thumb rather than first digit; superior helix rather than ear; canthus instead of eye).10
    • Use surrogate markers such as angiomas, seborrheic keratoses, or nevi, if landmarks are sparse.10
    • Clip hair to be short at biopsy sites on the scalp.10
    • Address any existing inflammatory dermatologic condition.10
    • Refrain from using cryotherapy or topical treatments for actinic keratoses on areas where a skin cancer biopsy may be performed.10
  • Procedure sign-in
    • Verify all elements of the Universal Protocol (UP), especially correct patient, correct procedure, correct side, and correct site.10,15
    • Review medical records and photographs (including original photographs if performing a follow-up procedure) in person with confirmation by the surgeon and patient.10
    • Document whether the diagram and three-point coordinate measurements are adequate and then mark the procedure site.10,20
  • Procedure time-out: Rereview all UP elements, especially agreement of site identification among all team members.10,15
  • Procedure sign-out
    • Include patient identification, date, and time of pathology specimen collection on the label.10,15
    • Verify that the specimen is placed into the container, labeled, and sent correctly for processing.10,20

Note: The strategies presented were primarily derived from prior literature, which includes sources with varying levels of evidence, such as expert opinion.21 Readers are encouraged to critically evaluate these strategies when implementing them in clinical practice.

Disclosure

Matthew A. Taylor declares no relevant or material financial interests. James S. Taylor owns noncontrolling common stock shares in AstraZeneca, Cigna, Johnson & Johnson, Merck, and Organon. He is a Food and Drug Administration special government employee and a Steering Committee member of the Cosmetic Ingredient Review. An adult nondependent child is employed by Pfizer.

This article was previously distributed in an April 1, 2026, newsletter of the Patient Safety Authority, available at https://patientsafety.pa.gov/newsletter/Pages/newsletter-april-2026.aspx.

About the Authors

Matthew A. Taylor (MattTaylor@pa.gov) is a research scientist on the Data Science & Research team at the Patient Safety Authority, where he conducts research, uses data to identify patient safety concerns and trends, and develops solutions to prevent recurrence.

James S. Taylor (TaylorJ@ccf.org) is a clinical professor of Dermatology at the Cleveland Clinic and its Lerner College of Medicine, with clinical research and teaching activities in patient safety, artificial intelligence, medical publishing, and occupational and allergic contact dermatitis. He is the author or co-author of more than 300 scientific publications.