Dysplastic nevus: why this term should be abandoned in dermatoscopy.

The term "dysplastic nevus" is a misnomer and should be abandoned. Dysplastic nevus is not just a name, it is the root of the concept that histomorphology (or any morphologic examination including dermatoscopy) is able to predict the fate of a benign melanocytic proliferation. There is no evidence that this hypothesis is true but there are observations that falsify it. Preferably a specific diagnosis should be made based on dermatoscopic pattern and, if this is not possible, on clinical or dermatoscopic grounds alone the term "nevus, not otherwise specified" should be used.

Analysis of interobserver reproducibility in grading histological patterns of dysplastic nevi.

BACKGROUND: Dysplastic nevi are among the most important cutaneous melanoma simulators. They are important risk markers for this neoplasia and can be its potential precursors. Some authors found a statistically significant relationship between the degree of dysplasia and the risk for developing melanoma. However, reproducibility of grading criteria ranged from poor to fair in the researched articles. OBJECTIVE: To test the reproducibility of the grading criteria proposed by Sagebiel et al. regarding dysplastic nevi. METHODS: Histological specimens of 75 dysplastic nevi were graded, independently and in a blinded fashion, according to preestablished criteria, by a panel of 10 pathologists with different levels of experience. Diagnostic agreement was calculated using weighted kappa and intraclass correlation coefficients. RESULTS: The average of weighted kappa values was 0.13 for all observers, 0.12 for dermatopathologists, 0.18 for general pathologists and 0.05 for residents. Intraclass correlation coefficient values were 0.2 for all observers, 0.18 for dermatopathologists, 0.33 for general pathologists and 0.15 for residents. CONCLUSIONS: Histopathological grading for dysplastic nevi was not reproducible in this Brazilian series, so the criteria used are not a helpful histopathological parameter for clinicopathological correlation.

Analysis of interobserver reproducibility in grading histological patterns of dysplastic nevi* / Avaliação da reprodutibilidade interobservador da graduação de padrões histológicos dos nevos displásicos

Dysplastic nevi are among the most important cutaneous melanoma simulators. They are important risk markers for this neoplasia and can be its potential precursors. Some authors found a statistically significant relationship between the degree of dysplasia and the risk for developing melanoma. However, reproducibility of grading criteria ranged from poor to fair in the researched articles. To test the reproducibility of the grading criteria proposed by Sagebiel et al. regarding dysplastic nevi. Histological specimens of 75 dysplastic nevi were graded, independently and in a blinded fashion, according to preestablished criteria, by a panel of 10 pathologists with different levels of experience. Diagnostic agreement was calculated using weighted kappa and intraclass correlation coefficients. The average of weighted kappa values was 0.13 for all observers, 0.12 for dermatopathologists, 0.18 for general pathologists and 0.05 for residents. Intraclass correlation coefficient values were 0.2 for all observers, 0.18 for dermatopathologists, 0.33 for general pathologists and 0.15 for residents. Histopathological grading for dysplastic nevi was not reproducible in this Brazilian series, so the criteria used are not a helpful histopathological parameter for clinicopathological correlation. .

Nevos displásicos estão entre os mais importantes simuladores de melanoma. São marcadores de risco para o desenvolvimento dessa neoplasia e podem ser seus precursores. Alguns autores observaram uma relação estatisticamente significativa entre o grau de displasia e o risco de desenvolvimento de melanoma. No entanto, a reprodutibilidade dos critérios para graduação variou de ruim a razoável nos artigos consultados. Testar a reprodutibilidade da graduação proposta por Sagebiel et al. para os nevos displásicos. Seções histológicas de setenta e cinco nevos displásicos foram graduadas, de forma independente e anônima, segundo critérios pré-estabelecidos, por um painel de 10 patologistas com diferentes níveis de experiência. A concordância diagnóstica foi calculada usando os coeficientes de kappa ponderado e de correlação intraclasse. A média dos valores de kappa ponderado foi de 0,13 para todos os observadores, de 0,12 para os dermatopatologistas, de 0,18 para os patologistas gerais e de 0,05 para os residentes. Os valores dos coeficientes de correlação intraclasse foram 0,2 para todos os observadores, 0,18 para os dermatopatologistas, 0,33 para os patologistas gerais e 0,15 para os residentes. A graduação histopatológica dos nevos displásicos não foi reprodutível nesta ...

Non-invasive identification of melanoma with near-infrared and skin impedance spectroscopy.

BACKGROUND/PURPOSE: An early diagnosis of cutaneous malignant melanoma is of high importance for good prognosis. An objective, non-invasive instrument could improve the diagnostic accuracy of melanoma and decrease unnecessary biopsies. The aim of this study was to investigate the use of Near-infrared and skin impedance spectroscopy in combination as a tool to distinguish between malignant and benign skin tumours. METHODS: Near-infrared and skin impedance spectra were collected in vivo on 50 naevi or suspect melanomas prior to excision. Received data were analysed using multivariate techniques and the results were compared to histopathology analyses of the tumours. A total of 12 cutaneous malignant melanomas, 19 dysplastic naevi and 19 benign naevi were included in the study. RESULTS: The observed sensitivity and specificity of the proposed method were 83% and 95%, respectively, for malignant melanoma. CONCLUSION: The results indicate that the combination of near-infrared and skin impedance spectroscopy is a promising tool for non-invasive diagnosis of suspect cutaneous malignant melanomas.

Improving the diagnostic accuracy of dysplastic and melanoma lesions using the decision template combination method.

BACKGROUND/PURPOSE: Melanoma is the most dangerous type of skin cancer, and early detection of suspicious lesions can decrease the mortality rate of this cancer. In this article, we present a multi-classifier system for improving the diagnostic accuracy of melanoma and dysplastic lesions based on the decision template combination rule. METHODS: First, the lesion is differentiated from the surrounding healthy skin in an image. Next, shape, colour and texture features are extracted from the lesion image. Different subsets of these features are fed to three different classifiers: k-nearest neighbour (k-NN), support vector machine (SVM) and linear discriminant analysis (LDA). The decision template method is used to combine the outputs of these classifiers. RESULTS: The proposed method has been evaluated on a set of 436 dermatoscopic images of benign, dysplastic and melanoma lesions. The final classifier ensemble delivers a total classification accuracy of 80.46%, with 67.73% of dysplastic lesions correctly classified and 83.53% of melanoma lesions correctly classified. CONCLUSION: The results show that the proposed method significantly increases the diagnostic accuracy of dysplastic and melanoma lesions compared with a single classifier. The total classification rate is also improved.

In vivo confocal microscopy for detection and grading of dysplastic nevi: a pilot study.

BACKGROUND: Dysplastic nevi are thought to be precursors of melanoma during a stepwise process. However, this concept is still controversial and precise correlation between clinical and histopathologic features is lacking. In vivo confocal microscopy represents a noninvasive imaging technique producing horizontal sections at nearly histopathologic resolution. OBJECTIVE: We sought to determine whether specific histologic features in dysplastic nevi have reliable correlates on confocal microscopy and to develop an in vivo microscopic grading system. METHODS: Sixty melanocytic lesions with equivocal dermatoscopic aspects, corresponding to 19 nondysplastic nevi, 27 dysplastic nevi, and 14 melanomas, were analyzed by confocal microscopy and histopathology, using the Duke grading criteria. RESULTS: All architectural and cytologic features of the Duke grading score had significant reflectance confocal microscopy correlates. Confocally, dysplastic nevi were characterized by a ringed pattern, in association with a meshwork pattern in a large proportion of cases, along with atypical junctional cells in the center of the lesion, and irregular junctional nests with short interconnections. A simplified algorithm was developed to distinguish dysplastic nevi from melanoma and nondysplastic nevi. The contemporary presence of cytologic atypia and of atypical junctional nests (irregular, with short interconnections, and/or with nonhomogeneous cellularity) was suggestive of histologic dysplasia, whereas a widespread pagetoid infiltration, widespread cytologic atypia at the junction, and nonedged papillae suggested melanoma diagnosis. LIMITATIONS: A small number of cases were evaluated because of the necessity to analyze numerous histopathologic and confocal features. CONCLUSION: The possibility to detect dysplastic nevi in vivo may lead to an appropriate management decision.

Nevus/Melanocytoma/Melanoma: an emerging paradigm for classification of melanocytic neoplasms?

CONTEXT: Until recently, the prevailing paradigm in classification and clinical management of melanocytic proliferations mandated dichotomous classification of all melanocytic lesions as either entirely benign (nevus) or entirely malignant (melanoma). However, some diagnostically challenging lesions cannot be unequivocally classified as nevus or melanoma by histologic evaluation of the primary tumor. Such lesions have been referred to as borderline or melanocytic tumors of uncertain malignant potential. OBJECTIVE: To review and update the problem of diagnostically difficult melanocytic proliferations and recent concepts regarding borderline melanocytic tumors. DATA SOURCES: Published literature and personal experience of the authors. CONCLUSIONS: Preliminary evidence indicates that it may be appropriate to expand the classification scheme of melanocytic neoplasms to include a third diagnostic category of melanocytic lesions of intermediate malignant potential that are capable of metastasis to regional lymph nodes but have limited potential for distant spread. We propose the term melanocytoma for this group of lesions. We believe that a nevus/melanocytoma/melanoma paradigm may provide a useful intellectual framework to understand, research, and clinically manage borderline melanocytic tumors.

Severe architectural disorder is a potential pitfall in the diagnosis of small melanocytic lesions.

BACKGROUND: Little is known about the significance of severe architectural disorder in small melanocytic lesions with features of dysplastic nevi (DN). METHODS: Using previously reported criteria, 355 consecutive DN were scored for architectural disorder and cytologic atypia. The DN were classified according to their size as small (equal or less than 3 mm) or large (greater than 3 mm). RESULTS: Of these 136 (38.3%) DN were classified as small. Grades of architectural disorder and cytologic atypia were equally distributed in small and large DN. Forty lesions were diagnosed as dysplastic nevi with severe architectural disorder (DNSAD). Thirteen DNSAD were small; of these, 84.6% were junctional. DN showing only mild to moderate architectural disorder were found to be predominantly compound. DN with severe cytologic atypia were mainly large (8/10 cases) with no particular type (junctional or compound) predominance. Seven cases displayed both severe architectural disorder and severe cytologic atypia; only one of these cases (a junctional lesion) measured less than 3 mm. CONCLUSIONS: Small melanocytic lesions displaying severe architectural disorder are mainly junctional and tend to show only mild cytologic atypia. Caution is needed when interpreting the degree of architectural disorder in these small melanocytic lesions, in order to avoid overdiagnosis of melanoma.

Consumption of the epidermis: a criterion in the differential diagnosis of melanoma and dysplastic nevi that is associated with increasing breslow depth and ulceration.

Consumption of the epidermis (COE), defined as thinning of the epidermis with attenuation of basal and suprabasal layers and loss of rete ridges adjacent to collections of melanocytes, is a recently coined term encompassing changes of the epidermal architecture associated with melanoma. To evaluate this feature as an additional diagnostic criterion for melanoma, we examined COE in 453 melanocytic lesions, including 213 invasive melanomas from a population-based series and 240 suspicious pigmented lesions from a clinic-based series, excluding halo and Spitz nevi. In the population-based series, COE was identified in 92/213 (43%) invasive melanomas and became progressively more frequent with increasing Breslow depth (P < 0.0001) and Clark level (P = 0.0002). COE was more frequent when mitotic figures (P < 0.0001), ulceration (P = 0.005), or vertical growth phase (P = 0.009) were present, but it was not significantly associated with age, gender, site, regression, or tumor-infiltrating lymphocytes. In the clinic-based series of pigmented lesions, COE was present in 2/25 (8%) in situ melanomas, 1/29 (3%) lesions classified as melanoma in situ/high-grade dysplastic nevi, and 1/40 (2.5%) high-grade dysplastic nevi. COE was not identified in 146 low-grade dysplastic, congenital, or common nevi. In the combined datasets, 94/96 (98%) lesions exhibiting COE were classified as melanoma. This study demonstrates that COE is frequently present in invasive melanomas, is associated with more aggressive histopathologic features (including increased Breslow depth and ulceration) and may be a useful supplementary diagnostic criterion for melanoma. Furthermore, the process leading to COE may be the first step in a progression to ulceration.

Variability in nomenclature used for nevi with architectural disorder and cytologic atypia (microscopically dysplastic nevi) by dermatologists and dermatopathologists.

BACKGROUND: Although a nevus with the microscopic features of a "dysplastic nevus" is commonly seen, the nomenclature used to describe such a lesion has been thought to be inconsistent. A 1992 National Institutes of Health (NIH) Consensus Conference sought to unify nomenclature and suggested that the term "nevus with architectural disorder" be used along with a comment on melanocytic atypia. METHODS: We performed a cross-sectional mail survey to determine preferred terminology as well as the level of adherence to the NIH-recommended nomenclature. All 856 active members of the American Society of Dermatopathology (ASDP) and 1100 (13.0%) of the 8471 active members of the American Academy of Dermatology (AAD) were surveyed. RESULTS: Five hundred and thirty-three ASDP members and 483 AAD members who fulfilled eligibility criteria completed the questionnaire. The term "dysplastic nevus" was favored by the largest number of responders (favored by 39.1% of ASDP members and 62.3% of AAD members), while the 1992 NIH Consensus Conference-recommended terminology was the second most popular term (25.3% of ASDP and 15.1% of AAD members). Dermatopathologists (OR = 1.9, p = 0.0001) and those who had dual training in dermatology and dermatopathology (OR = 1.6, p = 0.02 for ASDP members; OR = 2.3, p = 0.02 for AAD members) were more likely to adhere to the 1992 NIH Consensus Conference nomenclature. CONCLUSIONS: Despite attempts to unify nomenclature for microscopically dysplastic nevi through the NIH Consensus Conference, wide variation in terminology persists.