Highlights from the Literature

Dermatopathology Appropriate Use Criteria

by Alok Vij, MD

Nearly every person agrees that health care should be delivered with the highest quality and high value, offering patients increasingly effective, safe, and cost-conscious care. With an ever-expanding knowledge base about the pathophysiology of disease states comes an expanding litany of diagnostic and therapeutic tools, some of which have a hefty price tag. Knowing that every procedure, diagnostic or therapeutic, has benefits and risks as well as cost, appropriate use criteria have been developed in many specialties, synthesizing scientific evidence and the collective judgement of experts to guide the use of procedures in everyday practice. Studies have shown that qualifying appropriateness is correlated with addressing cost-effectiveness [1].

Due to a rise in the incidence of skin cancer as well as an increase in the number of Mohs surgeons, the use of Mohs surgery increased by 400% between 1995 and 2009. In 2012, appropriate use criteria (AUC) were developed for the application of Mohs surgery to treat cutaneous malignancies, taking location, size, histologic findings, and patient-specific factors into account to optimize the use of Mohs surgery in which the potential clinical benefits are expected to be greatest [2].

In a first for pathology-based subspecialties, the American Society of Dermatopathology, in concert with the American Association of Dermatology and the College of American Pathologists, released AUC for dermatopathology [3]. The panel reviewed ancillary tests in four broad categories: lymphoproliferative, melanocytic, soft tissue, and other. Similar to other criteria, each scenario was scored as “rarely appropriate,” “uncertain appropriateness,” and “usually appropriate.”

A panel of experts rated a total of 211 clinical scenarios, with consensus achieved in 188 (89%) and no consensus reached in 23 (11%). See Table 1 for consensus ratings. A consensus rating of “usually appropriate” was reached in 78 (37%) scenarios with 15 (7%) scenarios where the majority of ratings were “usually appropriate.” On the contrary, tests in 45 (21%) scenarios were deemed to be “rarely appropriate” with an additional 7 (3%) with the majority of ratings were “rarely appropriate.” Finally, consensus was reached for “uncertain appropriateness” in 43 (20%) scenarios.

 

N

%

Usually Appropriate

78

37

Majority Usually Appropriate

15

7

Uncertain Appropriateness

43

20

Majority Rarely Appropriate

7

3

Rarely Appropriate

45

21

Table 1: Number of scenarios stratified by consensus rating.

Examples of ratings for scenarios deemed “usually appropriate,” “uncertain appropriateness,” and “rarely appropriate” follow. Considering biopsies where the pathology was suggestive but not definitive for melanoma in adults or children, the use of fluorescent in situ hybridization (FISH) or comparative genomic hybridization (CGH) were deemed “usually appropriate” for many scenarios. For example, if the pathologic differential diagnosis included melanoma arising within a nevus versus a dysplastic nevus, either FISH or CGH would be appropriate follow-up tests to confirm the diagnosis.

However, in the same scenario, the use of quantitative real-time-polymerase chain reaction (qRT-PCR) was deemed of “uncertain appropriateness,” with the exception being cases in which a diagnosis could be made on histologic grounds. The authors noted, commendably, that after the rating process was started, additional literature was published describing the use of qRT-PCR in histologically ambiguous lesions; as a result, future revisions of the AUC are expected to change.

FISH, CGH, and qRT-PCR were all deemed “rarely appropriate” to confirm a diagnosis of melanoma or benign melanocytic nevus when the histology was definitive on its own right. The authors note that this rating is not surprising, as the diagnosis of melanocytic lesions is often confirmed based on histology alone.

With any set of guidelines, the final decision rests with the physician; however, codifying these recommendations after synthesizing the evidence and collective judgment of experts in the field is an important step in the process of delivering the highest quality care for patients while maximizing value.

References

  1. Kuntz et al. Expert panel vs decision-analysis recommendations for postdischarge coronary angiography after myocardial infarction. J Am Med Assoc 1999;282:2246-51.
  2. Connolly et al. AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: A report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery.  J Am Acad Dermatol 2012;67:531-50.
  3. Vidal, et al. Appropriate use criteria in dermatopathology: Initial recommendations from the American Society of Dermatopathology. J Am Acad Dermatol 2019;80:189-207.e11.