Search

Due to the potentially lethal nature of melanoma, prompt diagnosis and timely excision are of paramount importance. The clinical ABCD mnemonic (asymmetry, boarder irregularity, color variegation and diameter greater than 6mm) is one of the first and most widely used methods introduced to teach early melanoma recognition. Unfortunately, some melanomas can evade the clinical ABCD rule and mimic benign melanocytic nevi or mimic benign and/or malignant variants of non-melanocytic lesions. Over the last two decades, knowledge and insight have been gained into the dermoscopic primary morphology of melanocytic and non-melanocytic lesions. This has allowed for the use of dermoscopy to substantially increase the diagnostic accuracy for melanoma over clinical naked-eye examination alone. Unfortunately, even with dermoscopy, some melanomas remain difficult to diagnose. However, these difficult to diagnose melanomas often reveal subtle dermoscopic clues that allow for their correct identification. In this review, we focus on five variants of melanoma that are challenging to identify and discuss the dermoscopic features that can assist in their diagnosis.

Background Recent evidence suggests that melanoma is a family of different tumours with varying abilities to grow and metastasize. Trends in melanoma epidemiology show a strong increase in the incidence of thin melanoma, with no corresponding increase in mortality or incidence of thick melanoma. We initially evaluated five cases and found that none had baseline features suggestive of melanoma; excision was performed based on slight changes visible only in side-by-side comparisons of dermoscopic images. Objectives To assess the clinico-dermoscopic features and the growth patterns of melanomas that were excised after a follow-up of 1 year or more due to their inconspicuous features at the baseline consultation. Methods In a multicentre, retrospective study of histopathologically confirmed melanomas excised after follow-up, we analysed dermoscopic images obtained at the initial consultation and compared them with images obtained at the last follow-up consultation. Images were analysed and graded using standard algorithms and scored for changes in size, symmetrical or asymmetrical structural change, and development of new melanoma-specific criteria. An overall score reflecting the amount of change was calculated for each lesion. Results Our series consisted of 103 melanomas. After a median follow-up of 20 months, most lesions were still in situ or early invasive (median Breslow thickness of 0 48 mm), with only three lesions showing tumour thickness of 1 mm or more. The most frequent baseline characteristics were asymmetrical pigmentation (78.6% of lesions), reticular overall pattern (62.1%), and regression features (35.9%). Most melanomas (58.3%) showed minor to moderate changes over time, with

Objective: To determine the time required to perform a complete skin examination (CSE) as a means of opportunistic screening for skin cancer both without and with dermoscopy. Design: Randomized, prospective multicenter study. Setting: Eight referral pigmented lesion clinics. Patients: From June 2006 to January 2007, 1359 patients with at least 1 melanocytic or nonmelanocytic skin lesion were randomly selected to receive a CSE without dermoscopy or CSE with dermoscopy. For each patient, the total number of lesions and the duration of the CSE were recorded. A total of 1328 patients were eligible for analysis (31 were excluded because of missing data). Main Outcome Measures: The median time (measured in seconds) needed for CSE with and withoutdermoscopy and according to total cutaneous lesion count. Results: The median time needed for CSE without dermoscopy was 70 seconds and with dermoscopy was 142 seconds, a significant difference of 72 seconds (P

Objectives: To assess whether multiple observers can identify the same pigmented lesion(s) as being different from a patient's other moles ("ugly duckling" [UD] sign) and to explore whether the UD sign is sensitive for melanoma detection. Design: Baseline back images of 12 patients were obtained from a database of standardized patient images. All patients had at least 8 atypical moles on the back, and in 5 patients, one of the lesions was a histologically confirmed melanoma. The overview back images were supplemented with close-up clinical images of lesions. Participants were asked to evaluate whether the images showed any lesions on the back that differed from other nevi. Setting: Dermatology clinic specializing in pigmented lesions. Participants: Images were evaluated by 34 participants, including 8 pigmented lesion experts, 13 general dermatologists, 5 dermatology nurses, and 8 nonclinical medical staff. Main Outcome Measures: A lesion was considered a generally apparent UD if it was perceived as different by at least two-thirds of the participants. Sensitivity was defined as the fraction of melanomas identified as different. Results: All 5 melanomas (100%) and only 3 of 140 benign lesions (2.1%) were generally apparent as different. The sensitivity of the UD sign for melanoma detection was 0.9 for the whole group, 1.0 for experts, 0.89 for general dermatologists, 0.88 for nurses, and 0.85 for nonclinicians. A limitation of the study is that assessment was done in virtual settings. Conclusions: In the present study, melanomas were generally apparent as UDs. The potential of the UD sign for melanoma screening should be further assessed.

Background: Dermoscopy can assist clinicians in the evaluation and diagnosis of skin tumors. Since dermoscopy is becoming widely accepted and used in the medical community, there is now the need for a standardized method for documenting dermoscopic findings so as to be able to effectively communicate such information among colleagues. Objectives: Toward this end, the international Dermoscopy Society embarked on creating a consensus document for the standardization and recommended criteria necessary to be able to effectively convey dermoscopic findings to consulting physicians and colleagues. Methods: The Dermoscopy Report Steering Committee created an extensive list of dermoscopic criteria obtained from an exhaustive search of the literature. A preliminary document listing all the dermoscopic criteria that could potentially be included in a standardized dermoscopy report was elaborated and presented to the members of the International Dermoscopy Society Board in two meetings of the Society and subsequently discussed via Internet communications between members and the Steering Committee. Results: A consensus document including 10 points categorized as either recommended or optional and a template of the dermoscopy report were obtained. The final items included in the document are as follows: (1) patient's age, relevant history pertaining to the lesion, pertinent personal and family history (recommended); (2) clinical description of the lesion (recommended); (3) the two-step method of dermoscopy differentiating melanocytic from nonmelanocytic tumors (recommended); (4) the use of standardized terms to describe structures as defined by the Dermoscopy Consensus Report published in 2003. For new terms it would be helpful to provide a working definition (recommended); (5) the dermoscopic algorithm used should be mentioned (optional); (6) information on the imaging equipment and magnification (recommended); (7) clinical and dermoscopic images of the turner (recommended); (8) a diagnosis or differential diagnosis (recommended); (9) decision concerning the management (recommended); (10) specific comments for the pathologist when excision and histopathologic examination are recommended (optional). Limitations: The limitations of this study are those that are intrinsic of a consensus document obtained from critical review of the literature and discussion by opinion leaders in the field. Conclusions: Although it may be acceptable for a consulting physician to only state the dermoscopic diagnosis, the proposed standardized reporting system, if accepted and utilized, will make it easier for consultants to communicate with each other more effectively.

Background Based on the dermoscopic classification of acquired melanocytic naevi, six different dermoscopic types can be distinguished by morphology (globular, globular-reticular, globular-homogeneous, reticular, reticular-homogeneous, homogeneous) and by pigment distribution (uniform, central hyperpigmentation, central hypopigmentation, peripheral hyperpigmentation, peripheral hypopigmentation, multifocal hyper/hypopigmentation). It has been suggested that most individuals harbour one predominant dermoscopic type among their naevi. Objectives To evaluate whether the age of the patient influences the predominant naevus pattern observed in individuals with multiple acquired melanocytic naevi. Methods Individuals were recruited from the pigmented skin lesion clinic in Graz between July 2000 and February 2001. Individuals with at least 10 melanocytic naevi were selected consecutively until a total of 10 individuals in each of five age groups was obtained. Age groups were: 0-15 years, 16-30 years, 31-45 years, 46-60 years and > 60 years. Digitized images of acquired melanocytic naevi, defined as benign melanocytic proliferations having a diameter of at least 5 mm with a macular component and which were not apparent within the first year of life, were evaluated by dermoscopic criteria. The associations of dermoscopic features as a function of patient age were analysed. We calculated absolute numbers and frequencies, given as percentages, as well as predominance of the dermoscopic types of naevi in the different age groups. Results Analysis of 1268 naevi revealed that the globular pattern predominated in the youngest age group. By contrast, the reticular and/or homogeneous patterns were increasingly exhibited in naevi from older individuals (older than 15 years). Uniform pigmentation was most common in melanocytic naevi in the youngest age group, while central hyperpigmentation was predominantly seen in the group of individuals aged 16-30 years. Conclusions The predominance of dermoscopic types of melanocytic naevi varies according to the individual's age. Awareness of the age-related dermoscopic predominance of melanocytic naevi might allow more accurate recognition of dermoscopic patterns of melanocytic skin lesions that are unusual with respect to the individual's age. This observation may help in the early recognition of some 'banal'-appearing melanomas. Furthermore, the observations made in this study raise interesting questions regarding naevus evolution.

Background: Dermoscopy can assist clinicians in the evaluation and diagnosis of skin tumors. Since dermoscopy is becoming widely accepted and used in the medical community, there is now the need for a standardized method for documenting dermoscopic findings so as to be able to effectively communicate such information among colleagues. Objectives: Toward this end, the International Dermoscopy Society embarked on creating a consensus document for the standardization and recommended criteria necessary to be able to effectively convey dermoscopic findings to consulting physicians and colleagues. Methods: The Dermoscopy Report Steering Committee created an extensive list of dermoscopic criteria obtained from an exhaustive search of the literature. A preliminary document listing all the dermoscopic criteria that could potentially be included in a standardized dermoscopy report was elaborated and presented to the members of the International Dermoscopy Society Board in two meetings of the Society and subsequently discussed via Internet communications between members and the Steering Committee. Results: A consensus document including 10 points categorized as either recommended or optional and a template of the dermoscopy report were obtained. The final items included in the document are as follows: (1) patient's age, relevant history pertaining to the lesion, pertinent personal and family history (recommended); (2) clinical description of the lesion (recommended); (3) the two-step method of dermoscopy differentiating melanocytic from nonmelanocytic tumors (recommended); (4) the use of standardized terms to describe structures as defined by the Dermoscopy Consensus Report published in 2003. For new terms it would be helpful to provide a working definition (recommended); (5) the dermoscopic algorithm used should be mentioned (optional); (6) information on the imaging equipment and magnification (recommended); (7) clinical and dermoscopic images of the tumor (recommended); (8) a diagnosis or differential diagnosis (recommended); (9) decision concerning the management (recommended); (10) specific comments for the pathologist when excision and histopathologic examination are recommended (optional). Limitations: The limitations of this study are those that are intrinsic of a consensus document obtained from critical review of the literature and discussion by opinion leaders in the field. Conclusions: Although it may be acceptable for a consulting physician to only state the dermoscopic diagnosis, the proposed standardized reporting system, if accepted and utilized, will make it easier for consultants to communicate with each other more effectively.

WOS: 000320857700008, PubMed ID: 23553375, Importance: Nodular melanoma (NM) is a rapidly progressing potentially lethal skin tumor for which early diagnosis is critical. Objective: To determine the dermoscopy features of NM. Design: Eighty-three cases of NM, 134 of invasive non-NM, 115 of nodular benign melanocytic tumors, and 135 of nodular nonmelanocytic tumors were scored for dermoscopy features using modified and previously described methods. Lesions were separated into amelanotic/hypomelanotic or pigmented to assess outcomes. Setting: Predominantly hospital-based clinics from 5 continents. Main Outcome Measures: Sensitivity, specificity, and odds ratios for features/models for the diagnosis of melanoma. Results: Nodular melanoma occurred more frequently as amelanotic/hypomelanotic (37.3%) than did invasive non-NM (7.5%). Pigmented NM had a more frequent (compared with invasive non-NM; in descending order of odds ratio) symmetrical pigmentation pattern (5.8% vs 0.8%), large-diameter vessels, areas of homogeneous blue pigmentation, symmetrical shape, predominant peripheral vessels, blue-white veil, pink color, black color, and milky red/pink areas. Pigmented NM less frequently displayed an atypical broadened network, pigment network or pseudonetwork, multiple blue-gray dots, scarlike depigmentation, irregularly distributed and sized brown dots and globules, tan color, irregularly shaped depigmentation, and irregularly distributed and sized dots and globules of any color. The most important positive correlating features of pigmented NM vs nodular non-melanoma were peripheral black dots/globules, multiple brown dots, irregular black dots/globules, blue-white veil, homogeneous blue pigmentation, 5 to 6 colors, and black color. A model to classify a lesion as melanocytic gave a high sensitivity (>98.0%) for both nodular pigmented and nonnodular pigmented melanoma but a lower sensitivity for amelanotic/hypomelanotic NM (84%). A method for diagnosing amelanotic/ hypomelanotic malignant lesions (including basal cell carcinoma) gave a 93% sensitivity and 70% specificity for NM. Conclusions and Relevance: When a progressively growing, symmetrically patterned melanocytic nodule is identified, NM needs to be excluded.

Background: Most studies on dermoscopy of acral lesions were conducted in Asian populations. In this study, we analyzed these features in a predominantly Caucasian population. Objective: Estimate the prevalence of dermoscopic features in acral lesions, and assess their level of agreement between observers. Methods: In this retrospective multicenter study, 167 acral lesions (66 melanomas) were evaluated for 13 dermoscopic patterns by 26 physicians, via a secured Internet platform. Results: Parallel furrow pattern, bizarre pattern, and diffuse pigmentation with variable shades of brown had the highest prevalence. The agreement for lesion patterns between physicians was variable. Agreement was dependent on the level of diagnostic difficulty. Conclusion: Lesions with a diameter >1 cm were more likely to be melanoma. We found as well that a benign pattern can be seen in parts of melanomas. For this reason one should evaluate an acral lesion for the presence of malignant patterns first.

Background: The negative pigment network (NPN) is seen as a negative of the pigmented network and it is purported to be a melanoma-specific structure. Objectives: We sought to assess the frequency, sensitivity, specificity, and odds ratios (ORs) of NPN between melanoma cases and a group of control lesions. Methods: Digitalized images of skin lesions from 679 patients with histopathological diagnosis of dermatofibroma (115), melanocytic nevus (220), Spitz nevus (139), and melanoma (205) were retrospectively collected and blindly evaluated to assess the presence/absence of NPN. Results: The frequency of occurrence of NPN was higher in the melanoma group (34.6%) than in Spitz nevus (28.8%), melanocytic nevus (18.2%), and dermatofibroma (11.3%) groups. An OR of 1.8 emerged for the diagnosis of melanoma in the presence of NPN as compared with nonmelanoma diagnosis. Conversely, for melanocytic nevi and dermatofibromas the OR was very low (0.5 and 0.3, respectively). For Spitz nevi the OR of 1.1 was not statistically significant. When comparing melanoma with dermatofibroma, melanocytic nevus, and Spitz nevus, we observed a significantly higher frequency of multicomponent pattern (68.1%), asymmetric pigmentation (92.9%), irregularly distributed NPN (87.3%), and peripheral location of NPN (66.2%) in melanomas. Limitations: Further studies can provide the precise dermoscopic-histopathologic correlation of NPN in melanoma and other lesions. Conclusions: The overall morphologic pattern of NPN, such as the irregular distribution and the peripheral location of NPN, along with the multicomponent pattern and the asymmetric pigmentation could be used as additional features in distinguishing melanoma from Spitz nevus and other benign lesions. © 2012 by the American Academy of Dermatology, Inc.

Dermoscopy is useful for skin cancer screening, but a detailed approach is required that integrates this tool into a rational clinical work flow. To investigate clinician perceptions and behavior in approaching patients with skin tumors, a survey was launched by electronic mail through the International Dermoscopy Society. After 4 months, the responses were analyzed and significant findings calculated. Considering the current approach of study participants in examining patients for skin cancer, an up-to-date system of triage is presented in this review, which aims to promote an improved diagnostic accuracy and more timely management of skin malignancy.

Background: Early excision is the only strategy to reduce melanoma mortality, but unnecessary excision of benign lesions increases morbidity and healthcare costs. Objective: To assess accuracy in melanoma detection based on number-needed-to-excise (NNE) values over a 10-year period. Methods: Information was retrieved on all histopathologically confirmed cutaneous melanomas or melanocytic nevi that were excised between 1998 and 2007 at participating clinics. NNE values were calculated by dividing the total number of excised lesions by the number of melanomas. Analyses included changes in NNE over time, differences in NNE between specialized clinical settings (SCS) versus non-specialized clinical settings (NSCS), and patient factors influencing NNE. Results: The participating clinics contributed a total of 300,215 cases, including 17,172 melanomas and 283,043 melanocytic nevi. The overall NNE values achieved in SCS and NSCS in the 10-year period were 8.7 and 29.4, respectively. The NNE improved over time in SCS (from 12.8 to 6.8), but appeared unchanged in NSCS. Most of the effect on NNE in SCS was due to a greater number of excised melanomas. Higher NNE values were observed in patients younger than 40 years and for lesions located on the trunk. Limitations: No data concerning the use of dermatoscopy and digital monitoring procedures were collected from the participating centers. Conclusion: Over the 10-year study period, accuracy in melanoma detection improved only in specialized clinics maybe because of a larger use of new diagnostic techniques such as dermatoscopy. (J Am Acad Dermatol 2012;67:54-9.)

Background Melanomas vary in growth rate from rapidly developing nodular melanomas to slow-growing melanomas (SGM) that hardly change over years. Objectives To evaluate longitudinal changes in dermoscopic findings of SGM. Methods We retrospectively analysed a dermoscopic image dataset from 15 pigmented lesion clinics, of SGM that were followed sequentially by digital dermoscopy for at least 1 year. We evaluated baseline and follow-up images for changes in global pattern, organization, colours, structure and size. Results Our series consisted of 92 SGM. On follow-up, these melanomas developed the following dermoscopic findings: more homogeneous and less reticular global dermoscopic pattern; more frequent disorganization of pattern (baseline, 67% vs. follow-up, 79%); decreased prominence of light brown colour, increased prominence of dark brown colour, and increased frequency of the colours red, white, grey, blue and black (baseline: 29%, 3%, 18%, 6% and 33% vs. follow-up: 41%, 10%, 31%, 13% and 45%, respectively); decrease in prominence of dermoscopic structure of pigmented network, with a concomitant increase in prominence of structureless areas; and increased prominence or new appearance of melanoma-specific dermoscopic structures, including negative network, blue-white structures and blotches. The majority of lesions (75%) remained the same size or grew by < 2 mm in diameter. An increase in lesion size was associated with change in the total number of colours and structures (chi(2) = 14 3, P = 0.027) at follow-up. Conclusions While their diameter changed minimally over time, most SGM became more disorganized, revealed loss of network in favour of structureless areas, and developed new colours.

Objective: To compare melanoma characteristics and detection patterns in new vs established patients in a pigmented lesion clinic at Memorial Sloan-Kettering Cancer Center (MSKCC) during a 10-year period. Design: Single-center historical cohort study. Setting: Academic practice of 2 dermatologists with expertise in the management of pigmented skin lesions. Patients: The study included 394 patients diagnosed with cutaneous melanoma at MSKCC between 1998 and 2008. For the purposes of this study, we separated patients into 2 groups: established patients, defined as patients who have received professional services in a pigmented lesion clinic at MSKCC for at least 3 months, vs new patients, defined as patients new to our practice. Main Outcome Measures: Melanoma histologic characteristics and patterns of melanoma detection in established vs new patients. Results: Established patients had more in situ disease (70% vs 57%; P < .001) and thinner invasive melanomas (0.45 mm vs 0.82 mm; P = .002) and were less likely to present with negative prognostic attributes such as ulceration and dermal mitoses compared with new patients. In new patients, 63% of melanomas were physician detected vs 82% in established patients; 18% of all melanomas were patient detected. Dermatologist-detected melanomas were thinner compared with self-detected melanomas. The majority of self-detected melanomas were noted by patients because of change (64%). The overall benign to malignant biopsy ratio over the 10-year period was 5.4:1. Conclusion: Physician-based screening leads to higher rates of physician-detected melanoma and detection of thinner melanoma.

Objective To subclassify acquired nevi by dermoscopic pattern. Design Cross-sectional study with consecutive enrollment. Setting Pigmented lesion clinics in referral academic medical centers. Participants Individuals older than 2 years undergoing total skin examination were consecutively recruited between October 1, 2008, and May 31, 2009, and, based on their age, assigned to 1 of 8 groups. For each patient, the location and dermoscopic pattern of all nevi on the torso were recorded. Nevi were dermoscopically subclassified as globular, reticular, mixed (reticular-globular) pattern with peripheral or central globules, or unspecified pattern. Main Outcome Measure Frequency of dermoscopic nevus subtypes stratified by patient age and location of the nevi. Results A total of 5481 nevi in 480 individuals were evaluated. The number of all nevus subgroups, except for unspecified pattern nevi, significantly increased before and decreased after the fourth decade of life. Globular nevi were most prevalent on the upper trunk in children and adolescents; the number decreased consistently after the second decade of life. The reticular pattern was the most common nevus pattern after the second decade of life and the most common nevus subgroup on the upper and middle back. Although uncommon, central globular nevi also showed an age-dependent trend, similar to that of reticular nevi. Nevi with the peripheral globular pattern declined rapidly after the third decade of life and were no longer observed after the sixth decade. The number of unspecified pattern nevi was stable across all age groups. Conclusion Age, dermoscopic pattern, and location of nevi should be jointly considered when evaluating melanocytic lesions.

When I started my residency training about 11 years ago, I was immediately fascinated by the new morphologic dimension of skin lesions that is offered by dermoscopy, and accordingly, I focused my research on dermoscopy. At that time and as a young researcher, a recurrent statement was that “dermoscopy is not for future research as everything has already been described.” Instead, looking back on the research activities in the field of dermoscopy during the last 10 years proves that I was living at the beginning of a new and evolving era of noninvasive, diagnostic imaging techniques. In fact, dermoscopy gained increasing interest over this past decade, which is also reflected by the increasing number of publications on dermoscopy per year. Using, for example, simply “dermoscopy” to search for publications in the ISI Web of Science reveals that the number of publications increased significantly from 17 publications in 2000 to 138 in 2010. As a result, dermoscopy can be considered today as an integrative part in the routine diagnosis and management of patients with skin lesions. The fact that even after 10 years of intense research we still discover new features that aid the diagnosis is well reflected by this special issue. In this issue, the dermoscopic features of pigmented intraepidermal carcinoma, CD8-positive solitary pagetoid reticulosis, black hairy tongue, cylindroma, eccrine porocarcinoma, and rippled sebaceoma are described. In addition, a study focusing on the influence of pregnancy on the recurrence of melanoma failed to show an increased risk for recurrence, while another study reports the data of a new transition metal complex for photosensitizing properties and dye-sensitized solar cell. To this end, I conclude that although dermoscopy in 2011 is no longer a new technique but has become a standard tool for the diagnosis and management of patients with pigmented and nonpigmented skin lesions, there is still need and place for further research in this field. Iris Zalaudek Giuseppe Argenziano Ashfaq A. Marghoob Giovanni Pellacani H. Peter Soyer

Background: The presence of an atypical (irregular) pigment network (APN) can indicate a diagnosis of melanoma. This study sought to analyze the APN with texture measures. Methods: For 106 dermoscopy images including 28 melanomas and 78 benign dysplastic nevi, the areas of APN were selected manually. Ten texture measures in the CVIPtools image analysis system were applied. Results: Of the 10 texture measures used, correlation average provided the highest discrimination accuracy, an average of 95.4%. Discrimination of melanomas was optimal at a pixel distance of 20 for the 768 × 512 images, consistent with a melanocytic lesion texel size estimate of 4–5 texels per mm. Conclusion: Texture analysis, in particular correlation average at an optimized pixel spacing, may afford automatic detection of an irregular pigment network in early malignant melanoma.

Background & Development of melanocytic nevi is a complex process. Objective. The aim of the study was to characterize the in vivo confocal microscopy patterns and histopathologic correlates of melanocytic nevi. In addition, for the first time, confocal follow-up of characteristic nevi was performed documenting histologic changes in nevi. Methods: For the correlation study, 33 melanocytic nevi showing characteristic dermatoscopic patterns were studied by confocal microscopy. For the follow-up study 20 nevi were monitored for 12 to 18 months. Results: Reticular nevi showed two different confocal patterns, ringed and meshwork, mostly corresponding to lentiginous and nested junctional patterns, respectively. Globular nevi presented large junctional clusters, whereas cobblestone nevi were constituted by dermal dense melanocytic clusters. Homogeneous nevi did not show distinctive confocal and histopathologic findings. Nevi with a rim of globules presented a meshwork pattern with junctional clusters at the periphery. At the confocal follow-up Study all lesions showed limited dynamic changes resulting in stable dermatoscopic and confocal patterns, but 3 globular nevi with junctional nests at baseline evolved into reticular-meshwork pattern nevi with peripheral rim of globules-junctional nests. Limitations. Longer confocal follow-up of more melanocytic nevi is required to confirm this theory and to validate our preliminary findings. Conclusions. A model explaining the nevus classification and patterns Of evolution of nevi observed in the study was proposed. (J Am Acad Dermatol 2009;61:1001-13.)

A better understanding of the origin and evolution of nevi may help elucidate the pathways involved in melanoma-genesis. Herein we will present our theory of 2 distinct pathways to nevogenesis. We postulate, based on clinical observations and research data, that junctional nevi and superficial spreading melanomas arise from epidermal melanocytes, whereas dermal nevi and nodular melanomas originate in the dermis.

Objectives: To describe the dermoscopic structures and patterns associated with solitary angiokeratomas and to determine the sensitivity, specificity, positive predictive value, negative predictive value, and reproducibility of these dermoscopic features. Design: Multicenter retrospective study. Setting: University hospitals in Spain, Italy, Argentina, New York City, and Austria. Patients: There were 256 patients total, and 32 specimens each of solitary angiokeratomas, melanocytic nevi, Spitz-Reed nevi, malignant melanomas, pigmented basal cell carcinomas, dermatofibromas, seborrheic keratoses, and other vascular lesions (19 angiomas, 7 pyogenic granulomas, 3 spider nevi, 2 lymphangiomas, and 1 venous lake) were consecutively collected from the laboratories of 8 hospitals. Diagnoses of all patients' lesions were confirmed histopathologically. Intervention: Dermoscopic examination. Main Outcome Measures: The frequency, sensitivity, specificity, positive predictive value, negative predictive value, intraobserver agreement, and interobserver agreement of the different dermoscopic features associated with solitary angiokeratomas were calculated, and the differences were evaluated using the chi(2) or Fisher exact test. Results: Six dermoscopic structures were evident in at least 50% of the solitary angiokeratomas: dark lacunae (94%), whitish veil (91%), erythema (69%), peripheral erythema (53%), red lacunae (53%), and hemorrhagic crusts (53%). Dark lacunae exhibited a sensitivity of 93.8% and a specificity of 99.1% (P

Dermoscopy improves the diagnostic accuracy in the clinical evaluation of pigmented skin lesions, but it is also useful for the assessment of vascular structures that are not visible to the naked eye. As a consequence, dermoscopy has been employed more and more for the differential diagnosis of nonpigmented skin disorders, including tumors but also inflammatory and infectious diseases. This article provides a review of the dermoscopic features seen in various nonpigmented tumoral and nontumoral skin lesions as well as the dermoscopic criteria used for monitoring skin reactions to various treatments. Copyright (c) 2006 S. Karger AG, Basel.

A LTHOUGH THE CLINICAL CHARACTERIStics of keratoacanthomas (KAs) are well known, there is limited information about their dermoscopic appearance and features. We evaluated 15 KAs and welldifferentiated squamous cell carcinomas (SCCs). Dermoscopic evaluation revealed that all lesions demonstrated a white to yellowish round structure surrounded by a white halo. Given the resemblance to a pearl, we named this structure a keratinizing pearl. The most likely histopathologic correlate of a keratinizing pearl seen under dermoscopy is a horn pearl within the epidermis. In fact, biopsy specimens were obtained from all lesions, and the findings of histopathologic analyses were consistent. Horn pearls have been described in the pathology literature as characteristic structures that are composed of concentric squamous cell layers with increasing keratinization toward the center. A dermoscopic image of a welldifferentiated SCC with keratinizing pearls is shown in Figure, A. Histopathologic analysis revealed keratinizing pearls within the epidermis (Figure, B). Dermoscopic images of a KA-type SCC with keratinizing pearls (Figure, C) and a KA (Figure, D) are also shown. In conclusion, “keratinizing pearls” seen on dermoscopy may be suggestive of a well-differentiated keratinizing tumor, such as a KA and/or a well-differentiated SCC.