The dysplastic nevus: from historical perspective to management in the modern era: part I. Historical, histologic, and clinical aspects

Nanoparticle-Based Combination Therapy for Melanoma

Melanoma is a cutaneous carcinoma, and its incidence is rapidly increasing with every year. The treatment options for melanoma have been comprehensively studied. Conventional treatment methods (e.g., radiotherapy, chemotherapy and photodynamic therapy) with surgical removal inevitably cause serious complications; moreover, resistance is common. Nanoparticles (NPs) combined with conventional methods are new and promising options to treat melanoma, and many combinations have been achieving good success. Due to their physical and biological features, NPs can help target intended melanoma cells more efficiently with less damage. This creates new hope for a better treatment strategy for melanoma with minimum damage and maximum efficacy.

Novel Non-Invasive Quantification and Imaging of Eumelanin and DHICA Subunit in Skin Lesions by Raman Spectroscopy and MCR Algorithm: Improving Dysplastic Nevi Diagnosis

Malignant melanoma (MM) is the most aggressive form of skin cancer, and around 30% of them may develop from pre-existing dysplastic nevi (DN). Diagnosis of DN is a relevant clinical challenge, as these are intermediate lesions between benign and malignant tumors, and, up to date, few studies have focused on their diagnosis. In this study, the accuracy of Raman spectroscopy (RS) is assessed, together with multivariate analysis (MA), to classify 44 biopsies of MM, DN and compound nevus (CN) tumors. For this, we implement a novel methodology to non-invasively quantify and localize the eumelanin pigment, considered as a tumoral biomarker, by means of RS imaging coupled with the Multivariate Curve Resolution-Alternative Least Squares (MCR-ALS) algorithm. This represents a step forward with respect to the currently established technique for melanin analysis, High-Performance Liquid Chromatography (HPLC), which is invasive and cannot provide information about the spatial distribution of molecules. For the first time, we show that the 5, 6-dihydroxyindole (DHI) to 5,6-dihydroxyindole-2-carboxylic acid (DHICA) ratio is higher in DN than in MM and CN lesions. These differences in chemical composition are used by the Partial Least Squares-Discriminant Analysis (PLS-DA) algorithm to identify DN lesions in an efficient, non-invasive, fast, objective and cost-effective method, with sensitivity and specificity of 100% and 94.1%, respectively.

Predictive value of global dermoscopic pattern in patients diagnosed with cutaneous melanoma

Introduction

Dermoscopy is one of the most commonly used methods in early diagnosis of melanoma. It is conducted to differentiate between benign and malignant patterns in melanocytic lesions.

Aim

To determine if there is a predominance of one dermoscopic pattern in patients with melanoma and if there is a significant difference in dominant global dermoscopic pattern in patients with cutaneous melanomas correlated with patients’ sex and the location of the primary tumor.

Material and methods

The study included 162 patients with prior diagnosis of cutaneous melanoma. Dermoscopic and videodermoscopic pictures and patient data were analyzed with regard to the pattern: reticular, globular, homogeneous and mixed pattern (two-component pattern; reticular-globular pattern) with central or peripheral globules and multicomponent (mixed – at least 3 types of structures in one nevus).

Results

The reticular pattern was significantly more prevalent in male patients (38.57%, 27 patients) in comparison to female patients (18.45%, 17 patients). We also found a statistically significant lower prevalence of reticular pattern in patients diagnosed with melanomas located on upper limbs. The homogeneous pattern was statistically significantly more prevalent in patients in whom primary tumors were located on the head and upper limbs.

Conclusions

Our study suggests that predominant complex patterns are more commonly observed in patients diagnosed with cutaneous melanoma, although there is a significant number of patients with predominant reticular and homogeneous patterns, which are not often associated with an increased risk of development of melanoma.

Clinical, dermoscopic and histological assessment of melanocytic lesions: a comparative study of the accuracy of the diagnostic methods

BACKGROUND

  Worldwide, the incidence of melanoma is increasing, while late diagnosis is related to poor prognosis. A significant risk marker for melanoma is the presence of atypical nevi; therefore, it is of outstanding importance to make accurate clinical classification of common benign nevi, atypical nevi, and melanomas. The non-invasive method of dermoscopy allowed for the visualization of structures invisible to the naked eye and undoubtedly advanced the assessment of melanocytic lesions to a new dimension. This study aimed to evaluate the sensitivity and specificity of naked-eye examination and dermoscopy in diagnosing melanocytic lesions compared to the histopathological results, constituting the gold standard of diagnosis.

MATERIAL AND METHODS

One hundred eighteen melanocytic lesions were clinically evaluated via the naked eye and dermoscopic examination, using Pattern Analysis Methodology, and afterward, they were excised. The histopathological results were correlated with the findings.

RESULTS

According to the final histopathological analysis, 63 common benign nevi, 41 dysplastic nevi, and 14 cutaneous melanomas were excised in total. Clinical examination via the naked eye showed 78.2 % sensitivity and 71.4 % specificity in identifying the clinical atypia, while dermoscopy demonstrated 89.1 % sensitivity and 93.7 % specificity.

CONCLUSIONS

The results of the present study indicate a higher sensitivity and specificity of dermoscopy in evaluating and diagnosing melanocytic lesions compared to the naked-eye examination. HIPPOKRATIA 2021, 25 (4):156-161.

Melanoma risk stratification of individuals with a high-risk naevus phenotype - A pilot study

BACKGROUND/OBJECTIVES

High a naevus counts and atypical naevi are risk factors for cutaneous melanoma. However, many individuals with a high-risk naevus phenotype do not develop melanoma. In this study, we describe the clinical and dermoscopic attributes of naevi associated with melanoma in a high-risk naevus phenotype population.

METHODS

This single-centre, hospital-based case-control study included 54 prospectively enrolled adult patients ≥18 years old with a high-risk naevus phenotype (18 cases with a history of melanoma and 36 age- and gender-matched controls without a history of melanoma). We analysed clinical and dermoscopic images of the 20 largest naevi for each participant.

RESULTS

Cases had a higher mean age than controls (48.2 vs. 39.1 years, P = 0.007) but there was no difference in the male-to-female ratio between groups. Nearly, all participants (97%) were Fitzpatrick skin type II or III. Naevi in cases were more likely to be truncal, (72.6% vs. 53.6%, P = 0.01), particularly anterior truncal, (29.2% vs. 14.4%, P < 0.001) and larger than 8 mm (17.4% vs. 7.8%%, P = 0.01) compared to controls. CASH score of naevi did not differ between groups. Naevi in cases were more likely to have a multicomponent dermoscopic pattern than in controls (18.4% vs. 12.6%, P = 0.02).

CONCLUSION

Larger naevi, truncal naevi, and naevi, with a multicomponent dermoscopic pattern may be risk factors for melanoma among individuals with a high-risk naevus phenotype. Further studies are needed to validate these findings.

Targeting the ERK Signaling Pathway in Melanoma

The discovery of the role of the RAS/RAF/MEK/ERK pathway in melanomagenesis and its progression have opened a new era in the treatment of this tumor. Vemurafenib was the first specific kinase inhibitor approved for therapy of advanced melanomas harboring BRAF-activating mutations, followed by dabrafenib and encorafenib. However, despite the excellent results of first-generation kinase inhibitors in terms of response rate, the average duration of the response was short, due to the onset of genetic and epigenetic resistance mechanisms. The combination therapy with MEK inhibitors is an excellent strategy to circumvent drug resistance, with the additional advantage of reducing side effects due to the paradoxical reactivation of the MAPK pathway. The recent development of RAS and extracellular signal-related kinases (ERK) inhibitors promises to add new players for the ultimate suppression of this signaling pathway and the control of pathway-related drug resistance. In this review, we analyze the pharmacological, preclinical, and clinical trial data of the various MAPK pathway inhibitors, with a keen interest for their clinical applicability in the management of advanced melanoma.

MelaNostrum: a consensus questionnaire of standardized epidemiologic and clinical variables for melanoma risk assessment by the melanostrum consortium

BACKGROUND

Many melanoma observational studies have been carried out across different countries and geographic areas using heterogeneous assessments of epidemiologic risk factors and clinical variables.

AIM

To develop a consensus questionnaire to standardize epidemiologic and clinical data collection for melanoma risk assessment.

METHODS

We used a stepwise strategy that included: compilation of variables from case-control datasets collected at various centres of the MelaNostrum Consortium; integration of variables from published case-control studies; consensus discussion of the collected items by MelaNostrum members; revision by independent experts; addition of online tools and image-based charts; questionnaire testing across centres and generation of a final draft.

RESULTS

We developed a core consensus questionnaire (MelanoQ) that includes four separate sections: A. general and demographic data; B. phenotypic and ultraviolet radiation exposure risk factors and lifestyle habits; C. clinical examination, medical and family history; and D. diagnostic data on melanoma (cases only). Accompanying online tools, informative tables, and image-based charts aid standardization. Different subsections of the questionnaire are designed for self-administration, patient interviews performed by a physician or study nurse, and data collection from medical records.

CONCLUSIONS

The MelanoQ questionnaire is a useful tool for the collection and standardization of epidemiologic and clinical data across different studies, centres, cultures and languages. This will expedite ongoing efforts to compile high-quality data for pooled analyses or meta-analyses and offer a solid base for the design of clinical, epidemiologic and translational studies on melanoma.

Nuclear and cytoplasmic features in the diagnosis of Clark's nevi

BACKGROUND

Interpretation of Clark's nevi has generated debate over the years; although criteria have been proposed for grading morphological features of melanocytes, there is still confusion and variability in the assessment of these lesions.

METHODS

This is a retrospective observational study conducted on 100 Clark's nevi and 84 melanomas. A single expert dermatopathologist evaluated all blinded and randomized photomicrographs of both the Clark's nevi and melanomas for the presence of 14 cytologic features. Subsequently, a multivariate model was used to obtain sensitivity and specificity.

RESULTS

Clark's nevi showed a significantly higher frequency of absent-or-inconspicuous nucleoli over melanoma, whereas mitotic figures, pleomorphism, notching, multiple nucleoli, peppered moth nuclear pattern, flattened adjacent nuclei, prominent nucleoli and vesicular nucleus with rounded nucleoli were found significantly higher in frequency in melanomas.

CONCLUSION

Our data suggest that nuclear alterations are of value in the differentiation of atypical nevi from melanoma.

Melanocytic nevi and melanoma: unraveling a complex relationship

Approximately 33% of melanomas are derived directly from benign, melanocytic nevi. Despite this, the vast majority of melanocytic nevi, which typically form as a result of BRAF^V600E-activating mutations, will never progress to melanoma. Herein, we synthesize basic scientific insights and data from mouse models with common observations from clinical practice to comprehensively review melanocytic nevus biology. In particular, we focus on the mechanisms by which growth arrest is established after BRAF^V600E mutation. Means by which growth arrest can be overcome and how melanocytic nevi relate to melanoma are also considered. Finally, we present a new conceptual paradigm for understanding the growth arrest of melanocytic nevi in vivo termed stable clonal expansion. This review builds upon the canonical hypothesis of oncogene-induced senescence in growth arrest and tumor suppression in melanocytic nevi and melanoma.

Colorectal Cancer with Residual Polyp of Origin: A Model of Malignant Transformation

The majority of colorectal cancers (CRCs) arise from adenomatous polyps. In this study, we sought to present the underrecognized CRC with the residual polyp of origin (CRC RPO +) as an entity to be utilized as a model to study colorectal carcinogenesis. We identified all subjects with biopsy-proven CRC RPO + that were evaluated over 10 years at Mayo Clinic, Rochester, MN, and compared their clinical and pathologic characteristics to CRC without remnant polyps (CRC RPO −). Overall survival and disease-free survival overlap with an equivalent hazard ratio between CRC RPO + and RPO − cases when age, stage, and grade are adjusted. The somatic genomic profile obtained by whole genome sequencing and the gene expression profiles by RNA-seq for CRC RPO + tumors were compared with that of age -and gender-matched CRC RPO − evaluated by The Cancer Genome Atlas. CRC RPO + cases were more commonly found with lower-grade, earlier-stage disease than CRC RPO −. However, within the same disease stage and grade, their clinical course is very similar to that of CRC RPO −. The mutation frequencies of commonly mutated genes in CRC are similar between CRC RPO + and RPO − cases. Likewise, gene expression patterns are indistinguishable between the RPO + and RPO − cases. We have confirmed that CRC RPO + is clinically and biologically similar to CRC RPO − and may be utilized as a model of the adenoma to carcinoma transition.

From melanocytes to melanomas

Melanomas on sun-exposed skin are heterogeneous tumours, which can be subtyped on the basis of their cumulative levels of exposure to ultraviolet (UV) radiation. A melanocytic neoplasm can also be staged by how far it has progressed, ranging from a benign neoplasm, such as a naevus, to a malignant neoplasm, such as a metastatic melanoma. Each subtype of melanoma can evolve through distinct evolutionary trajectories, passing through (or sometimes skipping over) various stages of transformation. This Review delineates several of the more common progression trajectories that occur in the patient setting and proposes models for tumour evolution that integrate genetic, histopathological, clinical and biological insights from the melanoma literature.

Expression of Bcl-2, Melan A and HMB-45 in Dysplastic Nevi

BACKGROUND

From the first recognition of dysplastic nevi as a pathology per se, many debates have been raised and many histological and immunohistological studies have been conducted in order to establish the true significance of these lesions. Therefore, the aim of this study was to establish if there is a correlation between HMB-45, Melan A and Bcl-2 expression and the grade of dysplasia, as well as between the marker's staining patterns.

MATERIAL AND METHODS

Ten dysplastic nevi from six female patients were selected and their histological features (size, dysplasia), as well as the immunohistological staining patterns, were studied (HMB-45, Melan A, Bcl-2). The Pearson correlation coefficient and regression was calculated with Windows Excel Data Analysis.

RESULTS

We demonstrated that there was a notable correlation between the dysplasia and the size of the lesions (r(8)= 0.62 with p-value= 0.052), and also between Melan A and Bcl-2 (a r(6)= 0.73, p<0.05), but we did not obtain a statistically significant correlation between other features (p>0.05).

CONCLUSIONS

We can affirm, at least in our cases, there is a correlation between the grade of dysplasia and the size of the lesion, and also, that there is a correlation between Melan A and Bcl-2 staining, explained by MITF gene. These results were only partial concordant with those in other studies, therefore a larger number of cases is recommended to be further analyzed in order to clearly draw a conclusion.

In vivo assessment of optical properties of melanocytic skin lesions and differentiation of melanoma from non-malignant lesions by high-definition optical coherence tomography

One of the most challenging problems in clinical dermatology is the early detection of melanoma. Reflectance confocal microscopy (RCM) is an added tool to dermoscopy improving considerably diagnostic accuracy. However, diagnosis strongly depends on the experience of physicians. High-definition optical coherence tomography (HD-OCT) appears to offer additional structural and cellular information on melanocytic lesions complementary to that of RCM. However, the diagnostic potential of HD-OCT seems to be not high enough for ruling out the diagnosis of melanoma if based on morphology analysis. The aim of this paper is first to quantify in vivo optical properties such as light attenuation in melanocytic lesions by HD-OCT. The second objective is to determine the best critical value of these optical properties for melanoma diagnosis. The technique of semi-log plot whereby an exponential function becomes a straight line has been implemented on HD-OCT signals coming from four successive skin layers (epidermis, upper papillary dermis, deeper papillary dermis and superficial reticular dermis). This permitted the HD-OCT in vivo measurement of skin entrance signal (SES), relative attenuation factor normalized for the skin entrance signal (µ_raf1) and half value layer (z_1/2). The diagnostic accuracy of HD-OCT for melanoma detection based on the optical properties, µ_raf1, SES and z_1/2 was high (95.6, 82.2 and 88.9 %, respectively). High negative predictive values could be found for these optical properties (96.7, 89.3 and 96.3 %, respectively) compared to morphologic assessment alone (89.9 %), reducing the risk of mistreating a malignant lesion to a more acceptable level (3.3 % instead of 11.1 %). HD-OCT seems to enable the combination of in vivo morphological analysis of cellular and 3-D micro-architectural structures with in vivo analysis of optical properties of tissue scatterers in melanocytic lesions. In vivo HD-OCT analysis of optical properties permits melanoma diagnosis with higher accuracy than in vivo HD-OCT analysis of morphology alone.

The Genetic Evolution of Melanoma from Precursor Lesions

BACKGROUND

The pathogenic mutations in melanoma have been largely catalogued; however, the order of their occurrence is not known.

METHODS

We sequenced 293 cancer-relevant genes in 150 areas of 37 primary melanomas and their adjacent precursor lesions. The histopathological spectrum of these areas included unequivocally benign lesions, intermediate lesions, and intraepidermal or invasive melanomas.

RESULTS

Precursor lesions were initiated by mutations of genes that are known to activate the mitogen-activated protein kinase pathway. Unequivocally benign lesions harbored BRAF V600E mutations exclusively, whereas those categorized as intermediate were enriched for NRAS mutations and additional driver mutations. A total of 77% of areas of intermediate lesions and melanomas in situ harbored TERT promoter mutations, a finding that indicates that these mutations are selected at an unexpectedly early stage of the neoplastic progression. Biallelic inactivation of CDKN2A emerged exclusively in invasive melanomas. PTEN and TP53 mutations were found only in advanced primary melanomas. The point-mutation burden increased from benign through intermediate lesions to melanoma, with a strong signature of the effects of ultraviolet radiation detectable at all evolutionary stages. Copy-number alterations became prevalent only in invasive melanomas. Tumor heterogeneity became apparent in the form of genetically distinct subpopulations as melanomas progressed.

CONCLUSIONS

Our study defined the succession of genetic alterations during melanoma progression, showing distinct evolutionary trajectories for different melanoma subtypes. It identified an intermediate category of melanocytic neoplasia, characterized by the presence of more than one pathogenic genetic alteration and distinctive histopathological features. Finally, our study implicated ultraviolet radiation as a major factor in both the initiation and progression of melanoma. (Funded by the National Institutes of Health and others.).

[Dysplastic melanocytic nevus]

Dysplastic nevus is still a controversial entity both clinically and histologically. The occurrence of dysplastic nevus especially in the context of dysplastic nevus cell syndrome is associated with an increased risk for melanoma. The following minimal histological criteria should be fulfilled: nests of melanocytes varying in size and shape, bridging and confluent, proliferation of single melanocytes basal and suprabasal, cytoplasmic and nuclear atypia of melanocytes and subepidermal fibroplasia. The biological behavior (common nevus variant or precursor of melanoma?) is difficult to evaluate by presently available methods. The further development of new molecular biology techniques may allow a better prognosis of dysplastic nevi in an objective and reproducible manner. Against this background complete excision followed by clinical surveillance has to be recommended for the routine practice.

Selective use of sequential digital dermoscopy imaging allows a cost reduction in the melanoma detection process: a belgian study of patients with a single or a small number of atypical nevi

Background

Dermoscopy is a technique which improves melanoma detection. Optical dermoscopy uses a handheld optical device to observe the skin lesions without recording the images. Sequential digital dermoscopy imaging (SDDI) allows storage of the pictures and their comparison over time. Few studies have compared optical dermoscopy and SDDI from an economic perspective.

Objective

The present observational study focused on patients with one-to-three atypical melanocytic lesions, i.e. lesions considered as suspicious by optical dermoscopy. It aimed to calculate the “extra-costs” related to the process of melanoma detection. These extra-costs were defined as the costs of excision and pathology of benign lesions and/or the costs of follow-up by SDDI. The objective was to compare these extra-costs when using optical dermoscopy exclusively versus optical dermoscopy with selective use of SDDI.

Methods

In a first group of patients, dermatologists were adequately trained in optical dermoscopy but worked without access to SDDI. They excised all suspicious lesions to rule out melanoma. In a second group, the dermatologists were trained in optical and digital dermoscopy. They had the opportunity of choosing between immediate excision or follow-up by SDDI (with delayed excision if significant change was observed). The comparison of extra-costs in both groups was made possible by a decision tree model and by the division of the extra-costs by the number of melanomas diagnosed in each group. Belgian official tariffs and charges were used.

Results

The extra-costs in the first and in the second group were respectively €1,613 and €1,052 per melanoma excised. The difference was statistically significant.

Conclusions

Using the Belgian official tariffs and charges, we demonstrated that the selective use of SDDI for patients with one-to-three atypical melanocytic lesions resulted in a significant cost reduction.

A combination of p300 and Braf expression in the diagnosis and prognosis of melanoma

Background

To date only a handful of drugs are available for the treatment of melanoma. Among them vemurafenib, a Braf^V600E specific inhibitor, showed promising results in terms of response rate and increase in median survival time. However, its effectiveness is limited by development of resistance and the search for additional drugs for melanoma treatment is ongoing. The present study was performed to analyze the correlation between Braf expression and the expression of p300, a known down stream target of the mitogen activated protein kinase (MAPK) pathway, which was recently shown by us to be a prognostic marker for melanoma progression and patient survival.

Methods

The expression of Braf and p300 expression were correlated and analyzed by Chi-square test. A total of 327 melanoma patient cases (193 primary melanoma and 134 metastatic melanoma) were used for the study. Classification & regression tree (CRT), Kaplan-Meier, and multivariate Cox regression analysis were used to elucidate the significance of the combination of Braf and p300 expression in the diagnosis and prognosis of melanoma.

Results

Our results demonstrate that Braf expression is inversely correlated with nuclear p300 and positively correlated with cytoplasmic p300 expression. Braf and cytoplasmic p300 were found to be associated with melanoma progression, tumor size and ulceration status. CRT analysis revealed that a combination of Braf and p300 expression (nuclear and cytoplasmic), could be used to distinguish between nevi and melanoma, and primary from metastatic melanoma lesions. The combination of Braf and nuclear p300 was significantly associated with patient survival and nuclear p300 was found to be an independent predictor of patient survival.

Conclusion

Our results indicate a cross-talk between Braf and p300 in melanoma and demonstrate the importance Braf and p300 expression in the diagnosis and prognosis of melanoma.

Correlation between High Endothelial Vessels and Histopathological Features of Different Pigmented Lesions

PURPOSE

Tumor infiltrating lymphocytes are playing an important role in cutaneous melanoma being a strong prognostic parameter. Our goal was to study the presence of high endothelial vessels in correlation with the histopathological features in different pigmented skin lesions.

MATERIAL AND METHODS

our study group included 60 patients (20 cases with dysplastic nevi, 20 thin melanoma and 20 thick melanoma). For each patient we noted epidemiological and clinico-pathological characteristics including: age, gender, anatomic sites, regression, Breslow thickness, mitoses, Clark level and lymphocytic infiltration. Using immunohistochemistry staining we identified the presence of high endothelial vessels in our groups.

RESULTS

the most common localization of primary melanoma was trunk 57,5%, followed by extremities 35% and head 7,5%. We found positive MECA-79 vessels in 67% of primary melanoma samples and in 30% of dysplastic nevi. Lymphocytic infiltration was present in 80% samples of dysplastic nevi and 75% of primary melanomas. Using Kruskal Wallis non-parametric test we found a positive association between MECA-79+ vessels and different anatomic sites (p<0,01). We have also found a significant correlation between MECA-79+ vessels and the presence of regression in melanoma samples. In conclusion a better understanding of tumor microenvironment and mechanisms involved in anti-tumor response might play an important role in development of future melanoma therapeutic strategies.

Correlation between High Endothelial Vessels and Histopathological Features of Different Pigmented Lesions

Objectives: The main objective of this study was to observe the behavior of the fetal head position during labor, when starting from occiput anterior or posterior position and also to determine their importance in labor management (if the starting fetal head position can be a strong argument in favour of vaginal or cesarean delivery). Methods:187 patients in labor were included in this study, with gestational age over 37 weeks and estimated fetal weight over 2500 g, singleton pregnancy, cephalic presentation, empty urinary bladder. For these patients the ultrasound assessed parameters were: fetal head position at the beginning of labour and fetal head rotation during labour. Results: 89,18 percent of the patients starting from OTP (occiput transverse or posterior position) had a vaginal birth after an anterior rotation of the fetal head, and only 10,82 % presented persitent occiput posterior requiring cesarean section for delivery. Furthermore, considering only initial occiput posterior position, we observed an increased rate for cesarean section delivery (22,72%) by persistence of this position during labour. None of the patients starting with an anterior fetal head position rotated posteriorly. Conclusions: vaginal delivery in occiput anterior position was the most common result in both OTP and OP fetal head initial position. The main reason for cesarean delivery was persistent OP position. Patients with occiput posterior position were subsequent only to an initial posterior/transverse position.

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.

High-definition optical coherence tomography imaging of melanocytic lesions: a pilot study

High-definition optical coherence tomography (HD-OCT) is a non-invasive in vivo imaging technique with cellular resolution based on the principle of conventional optical coherence tomography. The objective of this study was to evaluate HD-OCT for its ability to identify architectural patterns and cytologic features of melanocytic lesions. All lesions were examined by one observer clinically and using dermoscopy. Cross-sectional HD-OCT images were compared with histopathology. En face HD-OCT images were compared with reflectance confocal microscopy (RCM). Twenty-six melanocytic lesions of 26 patients were imaged. Identification of architectural patterns in cross-sectional mode and cytologic features of pigmented cells in the epidermis, dermo-epidermal junction, papillary dermis, and superficial reticular dermis in the en face mode was possible by HD-OCT. HD-OCT provides morphological imaging with sufficient resolution and penetration depth to discriminate architectural patterns and cytologic features of pigmented cells in epidermis and dermis. The method appears to offer the possibility of additional three-dimensional structural information complementary to that of RCM, albeit at a slightly lower lateral resolution. The diagnostic potential of HD-OCT regarding malignant melanoma is not high enough for ruling out a diagnosis of malignant melanoma.

Dysplastic nevi and melanoma

Dysplastic nevi are described as being on a continuum between common acquired nevi and melanoma because they are morphologically and biologically intermediate between these 2 entities. Since initially being reported as histologic lesions observed in melanoma-prone families, there has been considerable debate about the definition of dysplastic nevi, the histologic and clinical criteria used to define them, and their biologic importance. Their role as precursor lesions for melanoma is not their primary role in their relationship to melanoma because of the rarity of transformation of any individual nevus to a melanoma. Although there is still no single, universally agreed upon histologic or clinical definition or even name for these nevi, dysplastic nevi should be considered important because of their association with an increased risk for melanoma.