Scoop-shave biopsy: When should it be used?

Acta Eruditorum

Abby Van Voorhees

Dr. Van Voorhees is the physician editor of Dermatology World. She interviews the author of a recent study each month.

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In this month’s Acta Eruditorum column, Physician Editor Abby S. Van Voorhees, MD, talks with Jeremy Bordeaux, MD, MPH, about his recent Dermatologic Surgery article, “To Scoop or Not to Scoop: The Diagnostic and Therapeutic Utility of the Scoop-Shave Biopsy for Pigmented Lesions.”

Dr. Van Voorhees: Define for us exactly what you mean by the scoop-shave technique. What are the advantages of this approach?

Dr. Bordeaux: It is very important to understand what exactly a “scoop-shave” is. The “scoop-shave” is very different than a standard shave biopsy. For this study all of the participating clinicians were trained to perform the scoop-shave and I made sure they understood how to do it and that they were doing it correctly. We marked out 2mm margins around the clinically evident lesion. We then used a curved blade to “scoop” down into the deep dermis. In general we were aiming for a depth of 2mm in thicker skin. In thin skin the scoop-shave would go at least into the deep dermis. The technique does need to be taught and it can be performed incorrectly. It is very important to note that if the scoop-shave is not being performed correctly, the results of this study will not be generalizable.

The main advantage of this approach is the short amount of time that it takes to perform compared to an excision or a punch biopsy.

Dr. Van Voorhees: When it comes to removing pigmented lesions many of us are leery of this approach. Let’s review the concerns.

Dr. Bordeaux: The main concern when removing a pigmented lesion is that it may be a melanoma. If it is in fact a melanoma, then treatment and prognosis is based on the Breslow’s depth. If the melanoma is transected on the deep margin, true Breslow’s depth is not known initially and an additional procedure will be needed to determine depth. This is the main concern that we as clinicians have: Will I transect a melanoma and not find out its true depth? In fact, this fear is what has led many practitioners to always punch biopsy or excise all pigmented lesions.

It should be noted that in our study the participating clinicians were instructed NOT to use the scoop-shave if they had a high clinical suspicion that the lesion they were sampling was a melanoma. If they encountered a pigmented lesion that they did not have a strong clinical suspicion that it was melanoma, they could then use any technique that they liked to remove the lesion.

However, using this approach we hypothesized that some melanomas would be sampled in the scoop-shave group (when the clinician did not have a high suspicion that it was melanoma). We wanted to know how often this would happen, and when it happened would we transect melanomas and not know the appropriate depth.[pagebreak]

Dr. Van Voorhees: Tell us about your study. How successful was the scoop-shave at completely removing lesions overall? How did it compare with standard excisions?

Dr. Bordeaux: This was a prospective cohort study. Clinicians were instructed not to use the scoop-shave if they had a high suspicion the pigmented lesion was a melanoma. If they did not think it was a melanoma, they were asked to use whatever technique they like, and to list their clinical suspicion of the diagnosis, and what their intent was (sample/fully remove the lesion). We then evaluated. We looked to see how accurate the clinicians were with their diagnosis, how often they completely removed the lesion when they attempted to, how often they encountered melanoma and whether or not the peripheral or deep margins were involved. Over the 10-month period, 333 lesions were obtained in the study. Over 70 percent of the lesions sampled (regardless of technique) were dysplastic nevi or benign nevi. The scoop-shave was used 134 times (standard excision 54, standard shave 104, punch biopsy 27, and punch excision 14). Standard excision returned negative margins 90 percent of the time and scoop-shave returned negative margins 73 percent of the time. Of the 134 scoop-shaves performed, only one (moderately dysplastic nevus) was present on the deep margin. After reviewing these slides, the intended depth was not reached for an appropriate scoop-shave in this specimen. 29 melanomas were encountered in the study. Nine of these were removed with the scoop-shave technique. None of them had positive deep margins.

Dr. Van Voorhees: Did the location of the lesion matter?

Dr. Bordeaux: The scoop-shave was most commonly used on the trunk, and rarely used on the face.

Dr. Van Voorhees: Was the ability to look at the peripheral portions of these tumors impaired?

Dr. Bordeaux: We processed our scoop-shaves like excisions (cut through entire specimen). This is also an important point. Some labs may simply bisect the specimen and look at one plane in a “biopsy.” It is important that the lab you are working with knows you are doing this technique and that you expect them to process it like an excision. Regardless of stated “negative margins” severely dysplastic nevi, in situ melanoma, and the invasive melanomas were all re-excised with appropriate margins.

Dr. Van Voorhees: What impact do the results of your study have on the way dermatologists should use the scoop-shave in practice?

Dr. Bordeaux: When performed appropriately, the scoop-shave can be a quick, safe way to sample pigmented lesions when the clinician does not have a high clinical suspicion that the diagnosis is melanoma.

Dr. Bordeaux is associate professor in the department of dermatology at Case Western Reserve University and University Hospitals Case Medical Center, as well as director of Mohs and dermatologic surgery and director of the melanoma program. His article appeared in Dermatologic Surgery, 2014;40:10771083. doi: 10.1097/01.DSS.0000452659.60130.68.