Dysplastic nevus part I: Historical perspective, classification, and epidemiology.

Since the late 1970s, the diagnosis and management of dysplastic nevi have been areas fraught with controversy in the fields of dermatology and dermatopathology. Diagnostic uncertainty and lack of standardized nomenclature continue to propagate confusion among clinicians, dermatopathologists, and patients. In part I of this CME review article, we summarize the historical context that gave rise to the debate surrounding dysplastic nevi and review key features for diagnosis, classification, and management, as well as epidemiology. We discuss essentials of clinical criteria, dermoscopic features, histopathologic features, and the diagnostic utility of total body photography and reflectance confocal microscopy in evaluating dysplastic nevi, with emphasis on information available since the last comprehensive review a decade ago.

Factors associated with suspected nonmelanoma skin cancers, dysplastic nevus, and cutaneous melanoma among first-time SpotMe screening program participants during 2009-2010.

BACKGROUND: There have been no studies of the American Academy of Dermatology's SpotMe skin cancer screening program to collectively analyze and determine the factors associated with suspected basal cell carcinoma (BCC), squamous cell carcinoma (SCC), dysplastic nevus (DN), and cutaneous melanoma (CM) diagnoses. OBJECTIVE: Describe the demographics, risk factors, and access to care profiles associated with suspected diagnoses of BCC, SCC, DN, and CM among first-time SpotMe screenees during 2009-2010. METHODS: We conducted a cross-sectional analysis of data from the SpotMe skin cancer screenings conducted in 2009 and 2010. We performed multivariable logistic regression analysis for each diagnosis, incorporating standard demographic, access to care, and risk factor variables in the models. RESULTS: Men, those without a regular dermatologist, persons reporting recently changing moles, and those with a personal history of melanoma were at increased risk for each of the suspected diagnoses analyzed. Uninsured persons were at increased risk for suspected malignancies (BCC, SCC, and CM). LIMITATIONS: Lack of histologic confirmation for diagnoses and cross-sectional design. CONCLUSION: Among first-time SpotMe participants, suspected diagnoses of BCC, SCC, DN, and CM shared several associated factors, which may be considered when planning outreach and screening for populations at risk for skin cancer.

Diagnostic utility of combining PRAME and HMB-45 stains in primary melanocytic tumors.

BACKGROUND: Pathologists face ongoing challenges distinguishing between benign and malignant melanocytic tumors. PRAME (PReferentially expressed Antigen in Melanoma) has a demonstrated value distinguishing between these types of lesions. However, the sensitivity of single immunohistochemistry is variable. HMB-45 is another valuable marker, but on its own, has a limited ability in setting of primary melanocytic tumors. This study sought to evaluate the diagnostic potential of a dual panel combining PRAME and HMB-45 in the assessment of primary melanocytic tumors. METHODS: 259 tumors, of which 141 were benign nevi, 31 dysplastic nevi (either low- or high grade dysplasia), and further 87 malignant melanomas, were retrieved from the department's archives and assessed by two experienced dermatopathologists. New sections were stained with PRAME and HMB-45, respectively. For PRAME, a nuclear, and for HMB-45, a cytoplasmic staining, was considered positive and scored as described in the literature on a scale from 0 to 4+. Only dermal component was assessed on HMB-45 stain. RESULTS: PRAME was diffusely expressed in only 1 benign nevus, with focal expression in further 28 compared to 22 diffusely and 103 focally HMB-45-positive benign nevi. 5 high-grade dysplastic nevi showed diffuse PRAME expression in epidermal component, with varying degree of positivity in adjacent dermal compartment, and further 8 dysplastic nevi showed only focal expression. HMB-45 was diffusely expressed in only 2, with focal expression in 23, and no apparent positivity in remaining 6 dysplastic nevi. In invasive melanoma group, PRAME stained >75 % cells in 64/87 tumors, however, 10/87 melanomas were completely negative. HMB-45 was captured diffusely in 49/87 melanomas, 32 showed patchy expression, and 6 tumors were blank negative. Diffuse 4+ PRAME positivity showed superior sensitivity and specificity of 73,6 % and 96,5 %, respectively, compared to HMB-45, 56,3 % and 86,0 %, respectively. No nevi showed double 4+ positivity, however, the sensitivity for double positivity was only 49,4 %. CONCLUSION: Our results confirm the superiority of PRAME over HMB-45 in the differential diagnosis of melanocytic tumors. However, combined staining can significantly increase specificity, rendering a benign diagnosis more unlikely in a double 4+ diffuse positivity setting.

Rapid Growth and Evolution of a Dysplastic Nevus During Pregnancy.

During pregnancy, many patients may experience changes in the size or characteristics of pigmented lesions including common and dysplastic nevi. These changes can be a cause for concern for the patient and their physician due to the potential for melanoma. Over the past several decades conflicting data has been reported about the relationship between pregnancy and the peripartum period and melanocytic nevi/melanoma. Although recent evidence suggests that prognosis is not worse among pregnant patients who develop melanoma, the discovery of several distinct types of estrogen receptors present in skin and effects of other hormones on melanoma suggest possible mechanisms through which melanocytic lesions may evolve. Many observations among patients with dysplastic nevus syndrome and those without this diagnosis can provide some evidence for how and why melanocytic lesions may change during pregnancy and provide support for clinical decisions in managing such concerns. Here we describe the case of a 27-year-old female who presented to the clinic with concerns of two moles which evolved and grew in diameter during two successive pregnancies but had no changes in the intervening time period.

Dysplastic melanocytic nevus: Are molecular findings the key to the diagnosis?

The primary differential diagnosis of melanoma is dysplastic nevus. Until now, the final diagnosis is based on histological findings. With modern techniques, pathologists receive very early melanocytic lesions, which do not fit all malignant criteria. In those cases, even the concurrence between specialists and intraobserver agreement is not good. A molecular test could be developed to improve the accuracy of melanocytic lesions diagnosis and help in challenging lesions. The objective of this study is to provide a literary review looking for molecular markers that characterize dysplastic nevi and could help surgical pathologists differentiate them from melanoma. Articles from PubMed presenting case series of dysplastic nevi and melanoma genomic analyses were considered. The search was conducted in PubMed looking for papers written in English, published in the ten years preceding April 2020. This review confirmed the absence of a pathognomonic molecular marker of dysplastic nevi. This is a heterogeneous group of lesions with an uncertain risk to become a melanoma. The molecular heterogeneity of dysplastic nevi, the variation of histological diagnostic criteria among services, and the diverse molecular techniques applied are challenging features that might hamper definitive diagnoses. However, currently, there appears to be limited value for molecular testing in the diagnosis of dysplastic nevi.

Histopathologic reassessment of melanoma and other melanocytic skin lesions excised in 2009 and 2018-2019. / Histopatologisk revurdering av melanom og andre melanocytære hudlesjoner eksidert i 2009 og 2018­19.

BACKGROUND: Histopathological assessment of melanoma and other melanocytic skin lesions can be difficult and can vary between pathologists. MATERIAL AND METHOD: Histopathological slides of 196 melanocytic skin lesions from 2009 and 2018-2019 were obtained from the archive of the Department of Pathology at Oslo University Hospital and classified into six diagnostic categories: 1) benign nevus, 2) irregular/dysplastic nevus, i.e. dysplastic nevus with moderate atypia, 3) nevus with severe atypia, i.e. dysplastic nevus with severe atypia, 4) melanoma in situ, 5) superficial spreading or lentiginous melanoma and 6) nodular melanoma. The slides were then examined independently and blindly by three experienced pathologists and categorised in the same way. Interobserver agreement was assessed with Cohen's kappa, and agreement with the original diagnosis was assessed by the proportion of assessments in the same diagnostic category. RESULTS: The kappa values for the assessments from the three pathologists ranged from 0.45 to 0.50. The proportion of reassessments in agreement with the original diagnostic category was 85.7 % (95 % CI 75.7 to 92.1), 29.2 % (19.9 to 40.5), 27.8 % (20.9 to 36.0), 78.3 % (70.4 to 84.5), 81.2 % (73.7 to 86.9) and 93.3 % (82.1 to 97.7), respectively, i.e. highest for nodular melanoma. The proportion of reassessments in which the diagnosis was more serious or less serious than the original diagnosis was higher and lower, respectively, for slides from 2009 than for slides from 2018-2019. INTERPRETATION: The differences between the pathologists' assessments and deviations from the original diagnoses can be explained by poorly reproducible diagnostic criteria, diagnostic entities with overlapping morphology and increasing awareness of early signs of malignancy. Some evolution in diagnostic practice cannot be ruled out.

Extreme winter weather: A force to be remembered in dermatopathology.

It is important for the dermatopathologist to be adept in differentiating tissue artifacts from normal tissue variants and pathologies. Numerous tissue artifacts have been described to date; however, once we are familiar with the common artifacts that appear in our practice, we may not immediately recognize other confounders. For example, dermatopathologists in more temperate regions of the country may not be familiar with freezing artifact. In this case series, we present three common diagnoses in dermatopathology that were obscured by the extreme winter weather that severely impacted the Southern United States in February 2021 and discuss methods to prevent these artifacts.

Clinical and histopathological features of pagetoid Spitz nevi of the thigh.

BACKGROUND: Pagetoid Spitz nevus is a rare subtype of Spitz nevus usually found on the lower extremities, particularly on the thigh of women. As a rare and under-recognized entity that can be misdiagnosed as melanoma, further characterization of clinical and histopathological features is needed to improve its recognition. METHODS: A retrospective analysis of all melanocytic neoplasms from the thigh diagnosed over a 3-year period. RESULTS: Fifty-five (15.4%) of the 357 melanocytic neoplasms on the thigh were Spitz nevi, the majority of them occurring in women (87.3%). Of the 55 Spitz nevi, 33 (60.0%) were pagetoid Spitz nevi, 14 (25.5%) were Reed nevi, and eight (14.5%) were conventional Spitz nevi. The mean age of patients with pagetoid Spitz nevi was 47.2, the majority being women (84.9%). Pagetoid Spitz nevi were small, with a mean histopathologic diameter of 4 mm, and often junctional (63.6%). Compared to Clark nevi of the thigh, pagetoid Spitz nevi comprised significantly more solitary melanocytes with a greater degree of scatter. CONCLUSIONS: These results suggest that Spitz nevi and, in particular, pagetoid Spitz nevi constitute a significant percentage of nevi on the thigh. Previously reported benign clinical and histopathological features of pagetoid Spitz nevi are confirmed in this study.

BRAF fusion Spitz neoplasms; clinical morphological, and genomic findings in six cases.

BACKGROUND: Fusions involving the BRAF gene are responsible for 5% of Spitz neoplasms. To better characterize them, we report the clinical, morphological, and genomic findings of six BRAF fusion Spitz tumors. METHODS: The morphological, clinical, and molecular findings of six BRAF fusion Spitz neoplasms assessed by next generation sequencing (NGS) were compared to a control set of Spitz without BRAF fusions. RESULTS: BRAF fusion Spitz tumors had frequent predominance of epithelioid morphology (4/6 cases), frequent high-grade nuclear atypia and pleomorphism (5/6 cases), and a frequent desmoplastic base (3/6 cases). Five of six cases were diagnosed as atypical Spitz tumor and one as Spitz nevus. All cases had uneventful clinical follow-up. There were five different fusion partners, with CLIP2 being the most frequent. Secondary pathogenic mutations were frequent and chromosomal copy number changes were seen in three of six cases by an NGS platform. CONCLUSIONS: BRAF fusions Spitz usually have epithelioid morphology, high-grade nuclear atypia, and desmoplasia. Chromosomal copy number changes are not infrequent. While our cases had uneventful follow-up, a meta-analysis of the literature suggests that among the fusion subtypes associated with Spitz tumors, they are among the subgroups more likely to develop distant metastasis.

Is it necessary to perform eye examination for patients with cutaneous atypical nevi?

Regular dermatological examination for patients with dysplastic nevi is indicated. However, the literature on whether those patients should also be examined by ophthalmologists or not regarding a relation between suspicious lesions for ocular melanoma and cutaneous dysplastic nevi is limited. In this study, we aimed to compare the findings of a single ophthalmologic examination between the group of patients with multiple atypical nevi with at least one histopathologically proven dysplastic nevus and another group without atypical nevi. We examined the eyes of 110 patients with multiple atypical nevi with at least one histopathologically proven dysplastic nevus (47 had the diagnosis of dysplastic nevus syndrome type A, B, C, D1 or D2) for any lesion and compared the results with a control group consisted of 110 gender, age and skin-type matched patients without atypical nevi no ocular melanoma was detected in any of the groups. The frequency of the conjunctival nevi, iris nevi, choroidal nevi and conjunctival acquired melanosis were similar in both groups. Iris freckles were detected more frequently in the study group. Conjunctival racial hyperpigmentation was detected more frequently in the control group (P < .05). In this study, any significant difference in the distribution of the ocular lesions with any risk of malignancy in the study and control groups was not observed. However, considering the limitations of the study, there may still be a need of regular ophthalmic examination for the patients with atypical nevi in case of having high risk factors for developing melanoma.

Surgical re-excision vs. observation for histologically dysplastic naevi: a systematic review of associated clinical outcomes.

BACKGROUND: The management of histologically dysplastic naevi (HDN) with re-excision vs. observation remains controversial because of lack of evidence about associated melanoma outcomes. OBJECTIVES: To assess published data on the development of biopsy-site primary cutaneous melanoma among biopsy-proven HDN managed with either re-excision or observation. METHODS: A systematic review of all published data: a total of 5293 records were screened, 18 articles were assessed in full text and 12 studies met inclusion criteria. No controlled trials were identified. RESULTS: Most studies (11 of 12, 92%) were retrospective chart reviews, and one was both a cross-sectional and cohort study. Many studies (nine of 12, 75%) had no head-to-head comparison groups and either only reported HDN that were re-excised or observed. A total of 2673 (1535 observed vs. 1138 re-excised) HDN of various grades were included. Follow-up varied between 2 weeks and 30 years. Nine studies reported that no melanomas developed. Eleven biopsy-site melanomas developed across three of the studies, six among observed lesions (0·39%) and five among re-excised lesions (0·44%). CONCLUSIONS: Based upon the available evidence the rates of biopsy-site primary melanoma were similarly low among observed lesions and re-excised lesions. This suggests that HDNs can be observed with minimal adverse melanoma-associated outcomes. However, all included articles were of low quality and further prospective trials could better guide clinical decision making.

The diagnostic value and histologic correlate of distinct patterns of shiny white streaks for the diagnosis of melanoma: A retrospective, case-control study.

BACKGROUND: Shiny white streaks (SWSs) are best visualized with polarized dermoscopy and correlate with dermal fibroplasia histopathologically. SWSs have been described at higher frequencies in melanomas than in benign nevi. OBJECTIVE: We assessed the diagnostic value of different patterns of SWSs and their histologic correlate in melanocytic lesions. METHODS: Polarized dermoscopic images of 1507 histopathologically diagnosed melanocytic neoplasms were analyzed for presence and pattern of SWSs. Histology was also reviewed for correlation. RESULTS: Among 1507 melanocytic neoplasms, SWSs were observed in 31 of 144 melanomas (22%) and 22 of 1363 benign neoplasms (1.6%) (P < .001). The sensitivity and specificity of SWSs for melanoma were 22% and 98%, respectively. Diffuse SWSs exhibited the greatest diagnostic value for melanoma, with sensitivity of 11.8% and specificity of 99.5%. Focal central and peripheral SWSs were comparable in diagnostic significance. The presence of SWSs was highly uncommon in dysplastic nevi, whereas in certain benign subgroups of nevi such as Spitz nevi and atypical genital special site nevi, SWSs were not uncommon. Diffuse SWSs correlated with greater breadth of deep fibroplasia than focal SWSs (P = .009), and SWSs correlated with greater Breslow depth among melanomas (P = .007). LIMITATIONS: This study was retrospective. CONCLUSION: Polarized dermoscopy is a valuable diagnostic tool in the identification of SWSs, a feature that is highly specific for melanoma.

microRNA in situ hybridization for miR-211 detection as an ancillary test in melanoma diagnosis.

Some melanocytic tumors can be histologically ambiguous causing diagnostic difficulty, which could lead to overtreatment of benign lesions with an unwarranted psychological distress or undertreatment of malignant cancers. Previously, we demonstrated that significantly decreased miR-211 expression in melanomas compared with melanocytic nevi could accurately discriminate malignant from benign tumors. Herein we show microRNA in situ hybridization for fluorescent detection of miR-211, suitable for paraffin-embedded tissues in 109 primary melanocytic tumors. miR-211 expression was significantly lower in melanomas vs nevi (P<0.0001), and receiver operating characteristic curve (area under the curve=0.862) accurately discriminated melanomas from nevi with 90% sensitivity and 86.2% specificity. Qualitatively, all dysplastic nevi expressed miR-211 at high (86%) and low (14%) levels, independent of the degree of nuclear atypia. All 35 melanocytic tumors with Spitz morphology expressed miR-211 independent of morphological classification, where clinical follow-up of these patients showed no recurrence at the site or metastasis in mean and median of 3 (ranging 2-5) years. Moreover, a decision tree learning analysis selected age and miR-211 miRNA in situ hybridization as the predictive variables for benign or malignant outcome in 88 patients correctly classified 92% (81 out of 88) of cases as proven by receiver operating characteristic curve (area under the curve=0.9029). These results support miR-211 as a leading miRNA candidate for melanoma diagnosis and miRNA in situ hybridization as a uniquely uncomplicated ancillary test.

The utility of dermoscopy-guided histologic sectioning for the diagnosis of melanocytic lesions: A case-control study.

BACKGROUND: Dermoscopy allows for visualization of morphologic structures beyond the epidermis, including features that may indicate early malignant transformation. However, dermoscopic features are rarely considered during routine histologic sectioning, and areas of clinical concern may be missed during microscopic evaluation. OBJECTIVE: We assessed the diagnostic impact of a dermoscopy-guided micropunch score for the evaluation of melanocytic lesions. METHODS: In this case-control study, we evaluated 150 scored melanocytic lesions. Original tissue specimens were reprocessed to create a control group, in which a new score was introduced elsewhere in the lesion to guide an alternative plane of section. Slides were reviewed in a randomized, double-blinded manner to assess histologic features and render a diagnosis. Dermoscopy was also reviewed. RESULTS: The proportion of cases with a higher grade in the original, dermoscopy-guided section was statistically significant. Four invasive melanomas were exclusively identified using the scoring protocol. The presence of regression structures, negative pigment network, radial streaming or pseudopods, and irregular blotches were highly specific for a higher diagnostic grade. LIMITATIONS: This study is retrospective and reprocessing tissue does not perfectly mimic routine sectioning. CONCLUSION: Dermoscopy can identify important, histologically high-grade areas, and this information can be used to optimize the sectioning of melanocytic neoplasms.

A nongrading histologic approach to Clark (dysplastic) nevi: A potential to decrease the excision rate.

BACKGROUND: Despite a lack of evidence that dysplastic nevi are precursors to melanoma, a large proportion of dermatologists continue to treat them as such. Emerging data suggest that histologic grading approach may result in many unnecessary excisions. OBJECTIVE: Using a nongrading approach to diagnosis of Clark/dysplastic nevi, the current study sought to define and determine the diagnostic uncertainty rate, and to report on the results of re-excisions of such lesions. METHODS: All melanocytic nevi submitted to an academic dermatopathology laboratory between January 1, 2007, and December 31, 2013, were categorized. The number of Clark nevi recommended for re-excision divided by the total number of Clark nevi was taken to be the diagnostic uncertainty rate. RESULTS: This nongrading approach resulted in an excision recommendation/diagnostic uncertainty rate of 11.1%. In 2% of the excised specimens, the diagnosis was changed to melanoma. LIMITATIONS: The study was performed at a single institution, and assigned diagnoses could not be verified other than by the diagnosing dermatopathologists. Lesions that were not submitted as re-excision specimens could have altered the results had they been available for evaluation. CONCLUSION: Compared with previously reported excision rates, the current study shows that the nongrading approach to Clark nevi results in a lower excision rate while still maintaining a low rate of change in diagnosis similar to the grading approach.

Practical application of new technologies for melanoma diagnosis: Part II. Molecular approaches.

The criterion standard for diagnosing cutaneous melanoma continues to be histologic examination. However, classifying some melanocytic lesions by conventional microscopy can be problematic if they exhibit some architectural or morphologic characteristics of both nevus and melanoma. Moreover, histologic appearance does not always predict biologic behavior. There is therefore a need and opportunity to develop new technologies that can facilitate the histologic diagnosis of melanoma and potentially help distinguish lesions with a lesser or greater risk of metastasis. In part II of this 2-part continuing medical education article, we will review the molecular technologies currently available for facilitating melanoma diagnosis, including comparative genomic hybridization, fluorescence in situ hybridization, and epidermal genetic retrieval. Our goal is to provide the clinician with an up to date understanding of these molecular approaches so that they can be applied to their management of challenging melanocytic lesions.

Dysplastic nevus: Fact and fiction.

The term "dysplastic nevus" (DN) implies that this nevus exists as a distinct and defined entity of potential detriment to its host. We examine the current data, which suggest that this entity exists as histologically and possibly genetically different from common nevus, with some overlapping features. Studies show that a melanoma associated with a nevus is just as likely to arise in a common nevus as in DN. Furthermore, there is no evidence that a histologically defined DN evolves into a melanoma or that the presence of 1 or more DN on an individual patient confers any increased melanoma risk. We suggest that the term "dysplastic nevus" be abandoned so that the focus can shift to confirmed and relevant indicators of melanoma risk, including high nevus counts and large nevus size.

IMP-3 EXPRESSION IN BENIGN MELANOCYTIC NEVI, DYSPLASTIC NEVI AND MALIGNANT MELANOMA: PRELIMINARY FINDINGS IN BULGARIAN PATIENTS.

IMP-3 is generally considered as an oncofetal protein, which plays a critical role in regulation of cell proliferation via an IGF-II-dependent pathway in K562 leukemia cells. IMP-3 expression has been detected in malignancies with various origins, while its appearance in adult tissue is generally considered abnormal, with some exceptions. IMP3 is also considered a prognostic biomarker in patients with renal cell carcinoma and clear-cell type ovarian carcinoma, hepatocellular carcinoma, pancreatic ductal adenocarcinoma and in patients with poorly differentiated thyroid carcinoma and uterine cervical carcinomas, testicular cancer and malignant melanoma. To our knowledge, no more than 4 PubMed-indexed studies have investigated the expression of IMP-3 in melanocytic lesions, namely its role in the differentiation between benign and malignant neoplasms. We investigated the expression of IMP-3 in a small series of benign melanocytic lesions, dysplastic nevi and melanomas, aiming to establish its significance as a marker for their distinction, comparing the results with those from the literature. IMP- 3 immunostaining was performed in 30 melanocytic lesions: 10 malignant melanomas, 10 dysplastic nevi and 10 benign melanocytic nevi. Our results revealed expression in 20% of dysplastic lesions and 40% of melanoma cases, while none of the benign nevi showed positive expression. These data contradict some of the results from other studies and raise some questions regarding the correlation between IMP- 3 and the degree of dysplasia of melanocytic nevi, as well as its potential relationship with prognostic parameters in melanoma, including tumor thickness and mitotic rate. Our results suggest that IMP-3 expression could be only an auxiliary marker for differentiation between dysplastic nevi and benign nevi, since although it is not expressed in all dysplastic lesions, staining correlates with the degree of dysplasia/atypia. It seems that IMP-3 expression is not a useful discriminator between dysplastic nevi and melanoma nor a good prognostic marker in melanoma.