Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications

doi:10.1016/j.jaad.2015.09.008

Journal of the American Academy of Dermatology

Volume 74, Issue 1, January 2016, Pages 75-80

https://doi.org/10.1016/j.jaad.2015.09.008 Get rights and content

Background

Histopathologic analysis remains the gold standard for the diagnosis of melanoma, however previous studies have shown a substantial rate of interobserver variability in the evaluation of melanocytic lesions.

Objective

We sought to evaluate discordance in the histopathological diagnosis and microstaging parameters of melanoma and subsequent impact on clinical management.

Methods

This was a retrospective review of 588 cases of cutaneous melanoma and melanoma in situ from January 2009 to December 2014 that were referred to Emory University Hospital, Atlanta, GA, for treatment. Per institutional policy, all outside melanoma biopsy specimens were reviewed internally. Outside and institutional reports were compared.

Results

Disagreement between outside and internal reports resulted in a change in American Joint Committee on Cancer pathologic stage in 114/588 (19%) cases, resulting in a change in management based on National Comprehensive Cancer Network guidelines in 105/588 (18%) cases.

Limitations

Given the retrospective nature of data collection and the bias of a tertiary care referral center, cases in this study may not be representative of all melanoma diagnoses.

Conclusion

These findings confirm consistent subjectivity in the histopathologic interpretation of melanoma. This study emphasizes that a review of the primary biopsy specimen may lead to significant changes in tumor classification, resulting in meaningful changes in clinical management.

Section snippets

Methods

After institutional review board approval, a retrospective review was performed of cutaneous melanoma cases referred to our institution from January 2009 to December 2014. It is policy at EUH that outside slides from original melanoma biopsy specimens are reviewed by a board-certified dermatopathologist at our institution before undergoing additional treatment. Referrals to EUH were made for routine treatment of melanoma, not for expert second opinion for diagnosis. Intrainstitutional

Results

Of the 871 cases of cutaneous melanoma referred to EUH for review between 2009 and 2014, 588 had available outside pathology reports and were included in the study. These represented interpretations by a total of 119 outside pathologists and 5 EUH dermatopathologists.

Discordance between outside and internal reports are presented in Table I. Changes in final diagnosis occurred in 11 (2%) cases (atypical melanocytic proliferation to invasive melanoma [3], melanoma in situ to invasive melanoma

Discussion

This study highlights the discordance among pathologists in the reporting of melanoma microstaging parameters. Although to our knowledge no previous studies have conducted a review on this scale and limited cases exclusively to melanoma or melanoma in situ, similar results have been reported. In a study by Hawryluk et al⁶ of diagnostically challenging pigmented lesions referred to a tertiary care center, the diagnostic discordance rate was 35%, resulting in a change in therapy in 13% of cases.

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Citation Excerpt :
Possible candidates include various forms of ‘pseudomelanoma’ including some that have been described and no doubt others that have yet to be described.38 The published experience of clinical groups that review outside slides prior to treatment in their institutions, where there is generally only a small subset of cases with disagreement that results in a change in diagnosis (although changes in management are not uncommon),39 suggests that there is not a very large number of such lesions being (recognisably) misdiagnosed as melanoma in the community. There has been recent evidence presented that some examples of lesions that are truly Spitz tumours may be indistinguishable from more usual melanomas (without sophisticated genomic testing) and these might form a significant subset of pseudomelanomas.40
Diagnostic error can be defined as deviation from a gold standard diagnosis, typically defined in terms of expert opinion, although sometimes in terms of unexpected events that might occur in follow-up (such as progression and death from disease). Although diagnostic error does exist for melanoma, deviations from gold standard diagnosis, certainly among appropriately trained and experienced practitioners, are likely to be the result of uncertainty and lack of specific criteria, and differences of opinion, rather than lack of diagnostic skills. In this review, the concept of diagnostic error will be considered in relation to diagnostic uncertainty, and the concept of overdiagnosis in melanoma will be presented and discussed.
Breslow thickness 2.0: Why gene expression profiling is a step toward better patient selection for sentinel lymph node biopsies
2022, Modern Pathology
Risk-stratification of cutaneous melanoma is important. Patients want to know what to expect after diagnosis, and physicians need to decide on a treatment plan. Historically, melanoma that had spread beyond the skin and regional lymph nodes was largely incurable, and the only approach to preventing a bad outcome was surgery. Through the seminal work of Alexander Breslow and Donald Morton, a system was devised to carefully escalate surgery based on primary tumor thickness and sentinel lymph node status. Today, we know that prophylactic lymph node dissections do not improve survival, but we continue to appreciate the prognostic implications of a positive sentinel node and the benefits of removing nodal metastases, which facilitates locoregional disease control. However, the question arises whether we can better select patients for sentinel lymph node biopsies (SLNB) as, currently, 85% of these procedures are negative and non-therapeutic. Here, we argue that gene expression profiling (GEP) of the diagnostic biopsy is a valuable step toward better patient selection when combined with reliable clinicopathologic (CP) information such as patient age and Breslow thickness. Recently, a CP-GEP-based classifier of nodal metastasis risk, the Merlin Assay, has become commercially available. While CP-GEP is still being validated in prospective studies, preliminary data suggest that it is an independent predictor of nodal metastasis, outperforming clinicopathological variables. The hunt is on for Breslow thickness 2.0.
Evidence concerning the accusation that melanoma is overdiagnosed
2021, Journal of the American Academy of Dermatology
Melanoma is one of the most commonly diagnosed malignancies in the United States and is responsible for the majority of deaths from skin cancer.
Since the 1970s, the incidence of melanoma has risen appreciably while melanoma-specific mortality has remained stable. This has raised a debate about potential overdiagnosis of melanoma. Herein, we review temporal trends in melanoma incidence and mortality and explore factors that may contribute to observed trends, including an aging population in the United States, ultraviolet exposure, increased numbers of biopsies by dermatologists and physician extenders, skin cancer screenings, histopathology criteria, and historic underdiagnosis. Additionally, we discuss melanoma overdiagnosis and the extent to which it may contribute to current trends.
The literature was reviewed.
Several factors may contribute to an increased incidence of melanoma, including an aging population, ultraviolet exposure, increased skin biopsies, skin cancer screenings, histopathologic criteria, historic underdiagnosis, and current overdiagnosis.
Further studies are required to determine exactly which tumors are being overdiagnosed, and how to improve patient outcomes with adjustment to physician's practice.
The rise in the incidence of melanoma observed since the 1970s is likely multifactorial.
Changes in melanoma diagnosis after presurgical tertiary care center review
2021, Journal of the American Academy of Dermatology
Five-year survival in patients with nodular and superficial spreading melanomas in the US population
2021, Journal of the American Academy of Dermatology
Although superficial spreading melanomas (SSM) are diagnosed as thinner lesions, nodular melanomas (NM) have a more rapid growth rate and are biologically more aggressive compared with other histologic subtypes.
To determine the difference in 5-year relative survival in patients with NM and SSM at the same Breslow depth and TNM stage.
A population-based cross-sectional analysis compared the 5-year relative survival of patients with NM and SSM using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)∗Stat software (version 8.2.1-8.3.5). Chi-square tests compared the proportions, and Kaplan-Meier method with Z-score compared 5-year relative survival.
For patients receiving a diagnosis between 2004 and 2009, 5-year relative survival was lower in NM compared with SSM (53.7% vs 87.3%; Z score, –41.35; P < .001). Similarly, for patients receiving a diagnosis between 2010 and 2015, 5-year relative survival was lower in NM compared with SSM (61.5% vs 89.7%; Z score, –2.7078; P < .01). Subgroup analyses showed inferior survival in NM in T1b, and survival differences remained significant after excluding patients with nodal or distant metastases.
Five-year relative survival is worse in NM compared with SSM especially in T1b, T2a, and T2b melanomas. Melanoma subtype should be taken into consideration when making treatment recommendations.
Technological advances for the detection of melanoma: Advances in molecular techniques
2020, Journal of the American Academy of Dermatology
The growth of molecular technologies analyzing skin cells and inherited genetic variations has the potential to address current gaps in both diagnostic accuracy and prognostication in patients with melanoma or in individuals who are at risk for developing melanoma. In the second article in this continuing medical education series, novel molecular technologies are reviewed. These have been developed as adjunct tools for melanoma management and include the Pigmented Lesion Assay, myPath Melanoma, and DecisionDx-Melanoma tests, and genetic testing in patients with a strong familial melanoma history. These tests are commercially available and marketed as ancillary tools for clinical decision-making, diagnosis, and prognosis. We review fundamental principles behind each test, discuss peer-reviewed literature assessing their performance, and highlight the utility and limitations of each assay. The goal of this article is to provide a comprehensive, evidence-based foundation for clinicians regarding the management of patients with difficult pigmented lesions.

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: Funding sources: None.

: Disclosure: Dr Stuart serves on the Board of Governors for the College of American Pathologists. Drs Patrawala, Maley, Parker, Swerlick, and Stoff, and Ms Greskovich have no conflicts of interest to declare.

: The findings from this research study were submitted as a meeting abstract to the American Society of Dermatopathology Conference, San Francisco, CA, October 8-11, 2015.

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Original articleDiscordance of histopathologic parameters in cutaneous melanoma: Clinical implications

Background

Objective

Methods

Results

Limitations

Conclusion

Section snippets

Methods

Results

Discussion

J Am Acad Dermatol

J Am Acad Dermatol

Hum Pathol

J Am Acad Dermatol

Hum Pathol

Eur J Cancer

J Am Acad Dermatol

Hum Pathol

J Clin Epidemiol

J Am Acad Dermatol

Surgery

Cancer statistics

CA Cancer J Clin

Recent trends in cutaneous melanoma incidence and death rates in the United States, 1992-2006

J Am Acad Dermatol

The health burden and economic costs of cutaneous melanoma mortality by race/ethnicity-United States, 2000 to 2006

J Am Acad Dermatol

Thickness, cross-sectional areas and depth of invasion in the prognosis of cutaneous melanoma

Ann Surg

Inter-observer variation between pathologists in the classification of cutaneous malignant melanoma in western Australia

Histopathology

Tumor thickness and prognosis in clinical stage I malignant melanoma

Cancer

Original article
Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications