Natural History of Atypical and Equivocal Melanocytic Lesions in Children: An Observational Study of 19 Cases

Digital dermoscopy follow‐up helps to identify patterns of change typical of common atypical nevi and early melanoma and improves the follow‐up of patients with atypical nevi. We report the morphologic changes observed over time in 19 atypical or equivocal acquired melanocytic nevi that underwent dermoscopic follow‐up. Two observers retrospectively examined digitalized dermoscopic images of 19 atypical melanocytic nevi from 15 children and young adults (median age 12 years, range 3–26 years). The images were assessed for global dermoscopic patterns at baseline and after a median 25‐month (range 6–138 mos) follow‐up. Ten (52.6%) nevi changed and nine (47.4%) retained a stable dermoscopic pattern. Of the 10 changing lesions, 2 of 4 homogeneous nevi evolved into a reticular pattern and 2 into a mixed pattern; 1 of 2 nevi with a mixed pattern evolved into a homogeneous nevus and 1 into a regressing nevus; 1 of 2 nevi with “other” patterns, such as negative pigment network and peppering throughout the lesion, evolved into a mixed nevus and 1 into a regressing nevus; 1 globular nevus evolved into a mixed pattern; and 1 starburst nevus evolved into a homogeneous nevus. The most striking results of our study were that atypical nevi can evolve into common nevi or they can regress, as documented by long‐term dermoscopic follow‐up. In children and young adults, dermoscopic follow‐up of atypical nevi might be a valid alternative to surgical excision and enables us to achieve new insights into the natural history of these nevi.     

Dermoscopic Evolution of Pediatric Nevi

BackgroundThe incidence of pediatric melanoma is very rare. Dermoscopic features help to distinguish pediatric melanoma and common nevi.ObjectiveTo study the evolution of dermoscopic findings in benign nevi in childhood through serial observation and photography.MethodsWe examined 504 melanocytic lesions in 100 patients. From each participant, dermoscopic images of the nevi from 4-year dermoscopic follow-up were obtained, including randomly selected nevi.ResultsThe most common dermoscopic patterns were homogeneous (193 nevi; 38.3%), globular (92 nevi; 18.3%), and reticular (86 nevi; 17.1%). Dermoscopic pattern changes were detected in 27% of patients aged 2~10 years and in 20% of patients aged 11~16 years. The main pattern changes consisted of the transition from homogeneous to globular-homogeneous (16%), from homogeneous to reticular-homogeneous (12%) and from globular to globular-homogeneous (10%). Although 257 of the 504 nevi (51.0%) have stable duration without size changes, 169 of the 504 nevi (33.5%) were enlarged, and 78 of the 504 nevi (15.5%) had become smaller.ConclusionThese results contrast with the prevailing view that dermoscopic patterns in pediatric nevi are usually characterized by globular patterns and that melanocytic nevi generally undergo a characteristic transition from a globular pattern to a reticular pattern. Fifty one percent of patients did not exhibit a size change. While 33% of patients had symmetrical enlargement, 15% of patients had involution. Therefore, enlargement is a common dermoscopic change in pediatric nevi, and is not a specific sign of pediatric melanoma.     

Clinical and dermoscopic features of small Reed nevus (<6 mm)

Background The differential diagnosis between Reed nevi and melanoma becomes more difficult if the lesion to analyse presents a small size, with a diameter of 6 mm or smaller. Many studies have reported various dermoscopic features of Reed nevi during their growth phases. In early stages of evolution, the lesions generally show a characteristic globular appearance typically found in childhood, followed by the so‐called starburst pattern. Objective The aim of the study was to identify the main dermoscopic features in small Reed nevi (<6 mm in size). Methods Using a computerized skin‐imaging database for melanoma prevention surgery at the Department of Dermatology of the University of Florence, 15 Reed nevi were selected among 103 small (<6 mm) melanocytic lesions consecutively excised. Images of small Reed nevi, independently blinded to histopathological diagnosis, were administered to a dermatologist expert in dermoscopy, who separately examined the clinical and the dermatoscopic images of small Reed nevi and evaluated their clinical and dermoscopic parameters. Results Analysis of the main dermoscopic patterns showed that 40% had a reticular pattern, 20% had a starburst pattern, 6.5% had a globular pattern, 6.5% had a homogeneous pattern and 27% had an atypical pattern. Conclusion We propose that small, early‐stage Reed nevus are not characterized by an evolution of growth patterns to a phenotype typical of larger lesions. We assume that the patterns are distributed in a linear manner between age groups, may all be present at the outset and thus are independent from the various stages of nevus development.     

Spitz Nevi and Other Spitzoid Neoplasms in Children: Overview of Incidence Data and Diagnostic Criteria

Spitz nevi are benign melanocytic neoplasms characterized by epithelioid or spindle melanocytes or both. In some rare cases their presentation overlaps with the clinical and histopathologic features of malignant melanoma, so a differential diagnosis can be difficult to make. Intermediate forms between Spitz nevi and malignant melanoma, with unpredictable behavior, have been called atypical Spitz tumors. A literature search was performed to review the clinical, dermoscopic, genetic, and histopathologic aspects of spitzoid tumors. Spitz nevi mainly occur in children, with no predilection for sex, and in young women. Common sites are the head and lower arms, where Spitz nevi present as pink nodules or hyperpigmented plaques. Spitzoid lesions may have diverse dermoscopic patterns: vascular, starburst, globular, atypical, reticular, negative homogeneous, or targetoid. The management of spitzoid lesions can be invasive or conservative; surgical excision is usually reserved for those with doubtful features, whereas clinical and dermoscopic follow‐up is preferred for typical pediatric Spitz nevi. The role of sentinel lymph node biopsy in atypical Spitz tumors is debated. Immunohistochemistry and new molecular techniques such as comparative genomic hybridization, polymerase chain reaction, and fluorescence in situ hybridization offer new diagnostic perspectives, investigating genetic alterations that are specific for malignant melanoma or for Spitz nevi.     

Digital dermatoscopic follow‐up of 1027 melanocytic lesions in 121 patients at risk of malignant melanoma

Objective  The aim of the presented prospective study was to use a digital dermatoscopic system to follow‐up patients with multiple melanocytic naevi, and to evaluate the frequency and character of dermatoscopic changes. Methods  We monitored selected melanocytic lesions with the use of a 6‐month follow‐up interval between check‐ups. We searched for changes in size, shape, symmetry, structure and colour. We defined the criteria for surgical excision and histopathological examination of changing lesions. We created a small group of excised unchanged atypical melanocytic naevi. Results  We completed dermatoscopic monitoring of 1027 melanocytic lesions in 121 patients at risk of developing malignant melanoma. The average total follow‐up interval was 21.0 months. We noticed a substantial enlargement of monitored lesions in 4.5% of cases, and there was a change of shape in 1.3% and change of asymmetry in 2.0%. The appearance of new structures, frequently being associated with malignant melanoma, was observed in 10 lesions, and it was predictive for the histopathological confirmation of this diagnosis in all cases. About 80% of monitored lesions remained unchanged. We excised 38 monitored lesions (seven melanomas in situ, four thin invasive melanomas and 27 melanocytic naevi). There was no melanoma excised in the group of unchanged atypical melanocytic lesions. Conclusion  Digital dermatoscopic follow‐up facilitates the recognition of thin malignant melanomas and helps to reduce the number of unnecessary excisions.     

Is rituximab therapy a risk factor for development of melanoma?

In the literature, there are reports about dermoscopic and size changes of nevi in patients undergoing biologic therapy and chemotherapeutics. There has not been any established data for melanoma and Rituximab therapy. Sixteen patients, with 94 nevi were included in this study. Dermoscopic images of follow‐up visits, which were performed at baseline, 3, 6, and 12 months after treatment, were evaluated. Suspicious lesions were excised. There was no increase in total nevus count. Although 61.7% of the 94 nevi have shown a stable duration without size changes, 26.5% had enlarged, and 11.7% had become smaller during our 1‐year experience of dermoscopic monitoring. There was not any pattern transformation. Atypical dots and clods appeared in 17% of nevi. All of the excised nevi were comparable with Clark nevi, there was no clue for melanoma development. According to our results, we found that Rituximab therapy influences nevus morphology, but there is no evidence that this was linked to melanoma development.     

The dermoscopic classification of atypical melanocytic naevi (Clark naevi) is useful to discriminate benign from malignant melanocytic lesions

BACKGROUND: The dermoscopic classification is a useful tool for handling patients with atypical naevi (Clark naevi). OBJECTIVES: To investigate if the dermoscopic classification of atypical naevi is of any value to discriminate benign from malignant melanocytic lesions. METHODS: Consecutive patients (n = 205) were included with 254 suspicious melanocytic lesions, confirmed by histopathology at the Pigmented Lesions Clinic of the Department of Dermatology, University Medical Center, University of Tuebingen, Germany. In this retrospective study, dermoscopic images of benign and malignant melanocytic lesions were classified according to the dermoscopic classification of atypical naevi (reticular, globular, homogeneous or combinations of two of these) and pigmentation (uniform, central hyper- or hypopigmentation, eccentric peripheral hyper- or hypopigmentation, or multifocal hyper- or hypopigmentation). The three-structure type (reticular, globular and homogeneous) was additionally defined. RESULTS: Reticular, homogeneous and reticular-homogeneous types were significantly more frequent in naevi than in melanomas, whereas the three-structure type was significantly more frequent in melanomas (P < 0.001). A sensitivity of 86.7%, specificity of 87.7% and diagnostic accuracy of 87.4% was obtained. Uniformly pigmented and centrally hyperpigmented types were significantly more frequent in naevi than in melanomas, whereas eccentric peripheral hyperpigmented and multifocal hyper- or hypopigmented types were significantly more frequent in melanomas (P < 0.001). CONCLUSIONS: The dermoscopic classification of atypical naevi (Clark naevi) is useful to discriminate benign from malignant melanocytic lesions. The three-structure type and eccentric peripheral hyperpigmentation were significantly more frequently found in malignant than in benign melanocytic lesions. The knowledge of these two dermoscopic types should be helpful for the management of patients presenting with multiple melanocytic lesions.     

Dermoscopy for the Pediatric Dermatologist Part III: Dermoscopy of Melanocytic Lesions

Melanocytic nevi encompass a variety of lesions, including blue, Spitz, congenital, and acquired nevi. These nevi can occasionally manifest clinical morphologies resembling melanoma, and the presence of such nevi in children can elicit anxiety in patients, parents, and clinicians. Dermoscopy has been shown to increase the diagnostic accuracy for melanoma and to help differentiate melanoma from nevi, ultimately aiding in the decision‐making process as to whether to perform a biopsy. Dermoscopy is the perfect instrument to use during the evaluation of pigmented skin lesions in children because it is painless and provides important information for the clinician that can assist in formulating appropriate management decisions. This review highlights the most common benign dermoscopic patterns encountered in nevi and discuss the 10 most common dermoscopic structures seen in melanomas. Lesions manifesting a benign dermoscopic pattern and lacking any melanoma‐specific structures do not need to be excised and can safely be monitored. In contrast, melanomas will invariably deviate from the benign nevus patterns and will usually manifest at least 1 of the 10 melanoma‐specific structures: atypical network, negative network, streaks, crystalline structures, atypical dots and globules, irregular blotch, blue‐white veil, regression structures, peripheral brown structureless areas, and atypical vessels. It is important to be cognizant of the fact that melanomas in childhood usually do not manifest the clinical ABCD features. Instead, they are often symmetric, amelanotic, nodular lesions. Although the clinical appearance may not be alarming, with dermoscopy they will invariably manifest at least one melanoma‐specific structure, the most common being atypical vascular structures and crystalline structures.     

Klinische Wertigkeit einer dermatoskopischen Klassifikation von Clark‐Nävi

Background and objectives: The aim of this study was to evaluate the practical value of the dermatoscopic classification of Clark nevi Patients and methods: Dermatoscopic images of 268 lesions clinically and dermatoscopically diagnosed as Clark nevi were presented to 2 dermatologists without knowledge of the histological diagnosis. The dermatologists evaluated the lesions according to a simplified version of the classification scheme for Clark nevi proposed by Hofmann‐Wellenhof and differentiated between 12 different types of Clark nevi. Results: The most common type of Clark nevus was the reticular‐homogenous type (n = 64, 23,9 %), followed by the globular‐homogeneous type (n = 32, 12 %) and by the homogenous type (n = 30, 11,2 %). The overall inter‐rater agreement between the examiners was moderate to good (kappa = 0,58). The highest level of agreement was found for the peripheral hyperpigmented type (kappa = 0,83). Histologically, 17 lesions (6,3 %) were diagnosed as melanomas. The frequency of melanoma was highest among the peripheral‐hyperpigmented type for one observer and among the homogenous type for the other observer. No melanoma was found among the globular, reticular‐globular, and the central‐hyperpigmented types. Conclusions: A dermatoscopic classification of Clark nevi is practically feasible and allows – to some extent – a risk stratification of Clark nevi, which could be useful for clinical management.     

Slow‐growing melanoma: a dermoscopy follow‐up study

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 < 2 mm size increase, with asymmetrical structural change, and without development of new melanoma‐specific criteria. Major changes were visible only after a mean follow‐up of 33 months. Conclusions This study provides evidence for the existence of a subgroup of slow‐growing melanomas, which may explain the increase in the incidence of thin melanoma, despite stable rates of thick melanoma and melanoma‐associated mortality.     

Dermoscopy of cutaneous melanoma metastases: A color‐based pattern classification

Dermoscopic studies about cutaneous metastases of malignant melanoma (CMMM) are few. Our objective was to analyze the dermoscopic features of CMMM and propose a new dermoscopic pattern classification based on color pigmentation and some specific dermoscopic features. A retrospective evaluation of 150 dermoscopic images of CMMM taken from 40 patients was performed. One hundred CMMM images were individually evaluated by six dermatologists in order to classify them according to four dermoscopic patterns: (i) blue pattern; (ii) pink pattern; (iii) brown pattern; and (iv) mixed pattern. One hundred and fifty dermoscopic images including 50 CMMM and 100 benign lesions were evaluated by five dermatologists to calculate the accuracy of these patterns in the recognition of CMMM. An intra‐ and interobserver reproducibility agreement study between all different dermoscopic pattern classifications was performed. Seventy‐five percent of our cases of CMMM showed a monochromatic pattern. Light brown pigmented halo, peripheral gray spots and polymorphic atypical vessels were the most significant focal dermoscopic structures. The reproducibility of the color‐based dermoscopic pattern classification was superior to previous dermoscopic pattern classification. In summary, a dermoscopic pattern classification based on color pigmentation and some specific dermoscopic features may be useful in recognizing early cutaneous melanoma metastasis. Multicentric studies are recommended in order to lower the impact of interobserver variability.     

178例掌跖部位黑素细胞性皮损的皮肤镜特点

目的 探讨掌跖部位黑素细胞性皮损的皮肤镜特点。方法 回顾性分析2009年9月至2011年10月在北京大学第一医院皮肤科行皮肤镜检查的掌跖部位黑素细胞性皮损的皮肤镜图像。结果 共分析了121例患者的155个良性黑素细胞性损害,22例患者的23个黑素瘤皮损。掌跖部位良性黑素细胞性皮损中最多见的皮肤镜模式为平行沟模式（占34.2%）,其次为纤维样模式（占22.6%）,有2个（1.3%）良性皮损表现为平行脊结构。23个黑素瘤皮损中12个（52.2%）出现平行脊结构,14个（60.9%）出现弥漫不规则的色素,且后者见于所有侵袭性黑素瘤中。纤维样结构作为肢端色素痣常见的一种良性皮肤镜模式,亦见于39.1%的黑素瘤中。结论 皮肤镜在区分掌跖部位良性黑素细胞痣和黑素瘤方面有一定价值     

Increased Melanocytic Nevi in Patients with Inherited Ichthyoses: Report of a Previously Undescribed Association

Abstract: Ichthyosis is a heterogeneous cornification disorder. Melanocytic lesions have not been previously described in association with ichthyosis. Their clinical importance lies in the fact that they may simulate melanoma clinically and dermoscopically, as seen in epidermolysis bullosa. The objective of this study was to evaluate the clinical, dermoscopic, and histopathologic features of nevi and lentigines in 16 patients with autosomal recessive congenital ichthyosis—lamellar ichthyosis and nonbullous ichthyosiform congenital erythroderma. Patients underwent general clinical examination dermoscopy. The more suspicious lesions were excised and to histopathologic examination. Most patients (n = 13) reported no personal or familial history of melanoma or atypical nevi. All of the patients had at least five atypical melanocytic lesions. Ten of the 16 patients had at least one atypical nevus or lentigo. This study suggests that increased atypical melanocytic nevi may be a feature of long‐standing congenital ichthyoses. Whether this finding is disease‐related or a coincidental observation is difficult to ascertain. As an unequivocal discrimination from malignant melanoma in vivo is not always possible, regular clinical follow‐up of patients with ichthyosis and increased or unusual nevi is recommended.     

Predominant dermoscopic patterns observed among nevi

BACKGROUND: It has been clinically observed that patients' "normal" moles resemble each other. Whether this concept is applicable to dermoscopic practice has not been sufficiently studied. OBJECTIVE: To investigate whether physicians evaluating dermoscopic images would identify common dermoscopic profiles of nevi within individual patients. METHODS: Images of 205 nevi belonging to 18 patients were evaluated by 2 dermatologists for dermoscopic global pattern, color, and specific structures. We defined dermoscopic patterns as dominant if seen in >or= 40% of the patient's nevi; a minor pattern was defined as 20 to 39%. RESULTS: A dominant pattern was seen in 15 patients (83%). In 13 (72%) of the patients, >or= 80% of the nevi were classified into one, two, or three global patterns. The reticular global pattern was the most prevalent dominant pattern, seen in 9 patients (50%); the homogeneous pattern was the most prevalent minor pattern, seen in 16 patients (89%). CONCLUSION: Individuals tend to have one to three predominant dermoscopic nevus global patterns.     

Epidermolysis bullosa nevus: an exception to the clinical and dermoscopic criteria for melanoma

BACKGROUND: Large acquired melanocytic nevi that occur in patients with epidermolysis bullosa (EB), referred to as EB nevi, may pose a diagnostic challenge because of their clinical and dermoscopic resemblance to melanoma. These unconventional melanocytic nevi have been encountered in all categories of hereditary EB, most of them in childhood. Although some of the reported cases have an alarming clinical appearance that is indistinguishable from melanoma, long-term follow-up has confirmed the benign nature of these rarely encountered melanocytic lesions. The histopathologic patterns of these nevi range from a banal congenital pattern to the problematic persistent pseudomelanoma pattern. OBSERVATION: We describe the clinical, dermoscopic, and histopathologic features of a large EB nevus in a toddler. Clinically, the lesion was markedly asymmetrical and irregularly pigmented with foci of stippled pigmentation and scarring, which easily fulfilled the ABCD criteria for melanoma. Accordingly, a false-positive score resulted when dermoscopy was performed. Histopathologically, a pattern of persistent melanocytic neoplasm was observed. In the following 18 months, dynamic changes of the lesion included near-complete disappearance of the pigment, which was replaced by scar, milia, and areas of healing ulcers. CONCLUSION: Epidermolysis bullosa nevi are dynamic melanocytic lesions that may simulate melanoma.     

Changes observed in slow-growing melanomas during long-term dermoscopic monitoring

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 (χ² = 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.     

Dermoscopic classification of atypical melanocytic nevi (Clark nevi).

OBJECTIVES: To create a dermoscopic classification of atypical melanocytic nevi (Clark nevi) and to investigate whether individuals bear a predominant type. DESIGN: Digital dermoscopic images of Clark nevi were classified according to structural features, ie, reticular, globular, or homogeneous patterns or combinations of these types. The nevi were also characterized as central hypopigmented or hyperpigmented, eccentric peripheral hypopigmented or hyperpigmented, or multifocal hypopigmented or hyperpigmented. SETTING: Two pigmented skin lesion clinics. PATIENTS: We examined 829 Clark nevi on 23 individuals. MAIN OUTCOME MEASURE: A reliable dermoscopic classification of Clark nevi and frequency of different dermoscopic types. RESULTS: Using the dermoscopic classification, the 829 Clark nevi were classified as follows: 221 (26.7%) as reticular, 167 (20.1%) as reticular-homogeneous, 148 (17.9%) as globular-homogeneous, 112 (13.5%) as reticular-globular, 89 (10.7%) as homogeneous, 84 (10.1%) as globular, and 8 (1.0%) as unclassified. Most individuals were prone to a predominant type of Clark nevus. Seven individuals (30%) showed a single type of Clark nevus in more than 50% of their nevi and 5 (22%) in more than 40% of their nevi. CONCLUSIONS: The proposed dermoscopic classification of Clark nevi is easily applicable and allows a detailed characterization of the different dermoscopic types of Clark nevi. Knowledge of these dermoscopic types should reduce unnecessary surgery for benign melanocytic lesions. Exact classification of the different types of Clark nevi is a necessary prerequisite for further clinical, dermoscopic, and histopathologic studies, which will give new insights in the biology of acquired melanocytic nevi.