Melanocytic nevi with special features: clinical‐dermoscopic and reflectance confocal microscopic‐findings

Histopathology is considered the ‘gold’ standard for the diagnosis and classification of melanocytic nevi, but the widespread use of in vivo diagnostic technologies such as dermoscopy and reflectance confocal microscopy (RCM), has enriched profoundly the knowledge regarding the morphological variability in nevi. This is because most morphological observations made via these in vivo tools are closely correlated with features seen in histopathology. Dermoscopy has allowed for a more detailed classification of nevi. As such, dermoscopy identifies four main morphologic groups (i.e. globular, reticular, starburst and structureless blue nevi), one group of nevi located at special body sites (i.e. face, acral, nail) and one group of nevi with special features. This latter category consists of nevi of the former categories, which are typified by peculiar clinical‐histopathological findings. They can be subdivided into ‘melanoma simulators’ including combined nevi, recurrent nevi and sclerosing nevus with pseudomelanomatous features, ‘targetoid’ nevi (i.e. halo, cockade, irritated targetoid haemosiderotic and eczematous nevus) and uncommon histopathological variants such as desmoplastic, white dysplastic or ballon cell nevus. While the dermoscopic and RCM patterns of the former categories have been studied in detail, little is currently known about the clinical morphology of the heterogeneous group of ‘special’ nevi. In this article, we describe the clinical, dermoscopic and RCM features of ‘special’ nevi and review the current literature on this group of melanocytic proliferations.     

The many faces of blue nevus: a clinicopathologic study

BACKGROUND: In recent years, several histopathologic variants of blue nevus have been identified, whose clinical and dermoscopic correlates need further clarification. METHODS: A comparative evaluation of histopathologic and dermoscopic features was carried out on 52 melanocytic proliferations belonging to the morphologic spectrum of blue nevus. RESULTS: On dermoscopy, all lesions showed a homogeneous, structureless pigment pattern, with a curious variety of colors (blue, white-blue, black, brown, and polychromatic). Histopathologically, the majority of blue lesions were common blue nevi (11/19); the majority of white-blue lesions were 'hypochromic' (sclerotic, hypomelanotic, and amelanotic) blue nevi (17/22); all the black lesions were 'compound' blue nevi (2/2); the majority of brown lesions were combined blue nevi (3/4); the unusual polychromatic dermoscopic appearance was often associated with a histopathologic diagnosis of deep penetrating nevus (2/5). CONCLUSION: A dermoscopic-pathologic approach now allows us to identify 'blue' (common) blue nevi, 'white' (hypochromic) blue nevi, 'black' (compound) blue nevi, 'brown' (combined) blue nevi, and 'polychromatic' (deep penetrating) blue nevi. A better recognition of the many dermoscopic faces of blue nevi is expected to give a morphologic guideline for the clinical management of these lesions.     

Dermoscopy patterns of halo nevi

BACKGROUND: Halo nevi (HN) are benign melanocytic nevi surrounded by a depigmented area (halo). This study aims to evaluate the dermoscopic features of HN and their changes during digital dermoscopic follow-up and to investigate the frequency of the halo phenomenon in a series of melanomas. OBSERVATIONS: In a retrospective study, digital dermoscopic images of HN from patients who attended the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, between October 1, 1997, and March 31, 2004, were reviewed and classified by dermoscopic morphologic criteria. For HN that were followed up with digital dermoscopy, the percentages of changes in the size of the nevus and halo components were calculated. In addition, digital dermoscopic images of histopathologically confirmed melanomas obtained from the same database were reviewed for the presence of an encircling halolike depigmentation. We classified 138 HN in 87 patients (mean age, 22.4 years). The most common dermoscopic structures were the globular and/or homogeneous patterns in more than 80% of HN. Follow-up of 33 HN revealed considerable size reduction of the nevus component, but this was not associated with significant structural changes. Of a total of 475 melanomas, only 2 revealed an encircling halo, but both displayed clear-cut melanoma-specific patterns according to dermoscopy. CONCLUSIONS: Halo nevi exhibit the characteristic dermoscopic features of benign melanocytic nevi, represented by globular and/or homogeneous patterns that are typically observed in children and young adults. Halo nevi reveal considerable changes of area over time during digital dermoscopic follow-up, albeit their structural patterns remain unchanged. For this reason and because melanoma with halolike depigmentation, despite being rare, additionally exhibits melanoma-specific dermoscopic criteria, the role of digital dermoscopic follow-up in the diagnosis of HN is insignificant.     

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.     

Use of Transparent Film Dressing for Dermoscopy of Mucosal Lesions

Genital and mucosal nevi are not uncommonly encountered in children. These type of nevi highlight challenges in performing a thorough dermoscopic examination. Contact dermoscopy can provide additional information about a nevus that non‐contact dermoscopy cannot. We propose applying a sterile transparent film dressing over the dermatoscope to act as a waterproof barrier that is also impermeable to bacteria and viruses. This provides a sanitary way to evaluate nevi in genital skin as well as on other mucosal surfaces.     

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.     

Morphologic changes of a pigmented Spitz nevus assessed by dermoscopy

Pigmented Spitz nevus may simulate cutaneous melanoma clinically and histopathologically. In an effort to characterize Spitz nevi using dermoscopy, we documented the dermoscopic features of a single pigmented Spitz nevus over a 6-month period. A 3-year-old boy had a brownish black papule, 3 mm in diameter, on the dorsum of the first finger of his left hand, clinically diagnosed as a Reed nevus. Two follow-up examinations were performed after 3 and 6 months, when the lesion finally was excised for histopathologic examination. Dermoscopically, a globular pattern was recognized during the initial examination, whereas a starburst pattern was identified 3 months later. After 6 months, a variation of the starburst pattern was still detectable. Based on our observation, the globular and the starburst patterns might be considered different morphologic expressions corresponding to the evolutionary phases of pigmented Spitz nevi.     

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.     

The Framingham school nevus study: a pilot study

OBJECTIVES: To (1). describe nevus patterns using digital photography and dermoscopy; (2). evaluate the relationship between host and environmental factors and prevalence of nevi in schoolchildren; and (3). demonstrate the feasibility of conducting a longitudinal study. DESIGN: Cross-sectional survey and 1-year prospective follow-up study. PARTICIPANTS: Students from 2 classrooms, grades 6 and 7, in the Framingham, Mass, school system (N = 52). MAIN OUTCOME MEASURES: A survey was completed by students and 1 of their parents that included questions on demographic and phenotypic characteristics, family history of skin cancer, and sun exposure and protection practices. An examination of nevi on the back was performed that included digital photography and digital dermoscopy. Follow-up child and parent surveys and examinations were conducted at 1-year follow-up. RESULTS: At baseline, the median number of back nevi was 15 (mean [SD], 21.9 [15.3]). Older age, male sex, fair skin, belief that a tan is healthier, tendency to burn, and sporadic use of sunscreen were positively associated with mole count, although age was the only statistically significant factor. Predominant dermoscopic patterns for the index nevus were as follows: 38% globular, 14% reticulated, 38% structureless, and 10% combinations of the above patterns with no predominant characteristic. The overall participation rate from baseline to follow-up was 81% (42/52) for the skin examination process. At the 1-year follow-up examination, new nevi were identified in 36% of students (n = 15), while 9.6% of baseline index nevi had changes in the dermoscopic pattern. Dominant dermoscopic pattern was related to nevus size: smaller nevi tended to be structureless, while larger nevi were of mixed pattern. CONCLUSION: This study supports the feasibility and utility of digital photography and dermoscopy for the longitudinal study of nevus evolution in early adolescence.     

Dysplastic changes in different types of melanocytic nevi. A unifying concept

We observed histopathologic changes previously described in dysplastic melanocytic nevi in association with a dermal component characteristic of other types of melanocytic nevi or overlapping with features of other varieties of nevi. In order to determine the frequency of these changes, we studied 2,164 cases of compound melanocytic nevi that fulfilled the histopathologic criteria for the diagnosis of compound dysplastic nevus, including architectural pattern, cytologic features, and mesenchymal changes. Of the 2,164 compound dysplastic melanocytic nevi, 1,895 (87.6%) had the histopathologic characteristics previously described for dysplastic nevus, 179 (8.3%) showed a dermal component with a congenital pattern, 67 (3.1%) demonstrated epidermal and dermal characteristics of Spitz's nevus, 8 (0.3%) had features of a combined blue nevus, 13 (0.6%) had a halo phenomenon and 2 (0.1%) showed dermal neuronevus. By considering these nevi as variants of dysplastic nevi, one may apply a unified conceptual basis for their nomenclature. In order to completely describe the appearance of the nevus, we named them by adding the term "dysplastic", to their main histopathologic subtype. Accordingly, six different varieties of dysplastic nevi were identified: 1) dysplastic nevus (original); 2) dysplastic nevus with a congenital pattern; 3) dysplastic Spitz's nevus; 4) dysplastic combined blue nevus; 5) dysplastic halo nevus; and 6) dysplastic neuronevus. In summary, we conclude that the histopathologic criteria previously reported for the diagnosis of dysplastic nevi may be found in association with a dermal component characteristic of other types of melanocytic nevi or may have overlapping features with other variants of nevi.     

Correlation of dermoscopic structures of melanocytic lesions to reflectance confocal microscopy

OBJECTIVE: To determine the utility of reflectance confocal microscopy (RCM) in the in vivo evaluation of dermoscopic structures of melanocytic lesions. DESIGN: For each described dermoscopic feature, we evaluated by RCM at least 2 melanocytic lesions. A digital camera connected to the confocal computer enabled direct analysis of the dermoscopic structures. To ascertain precision of correlation, the orientation of the dermoscopic and RCM images were compared using a superimposed grid. SETTING: Dermatology clinic specializing in pigmented lesions. Patients Eleven patients with melanocytic lesions, including 2 melanomas, 1 Spitz nevus, 7 dysplastic nevi, and 1 compound nevus. Main Outcome Measure Direct correlation of structures seen using dermoscopy with those seen using RCM. RESULTS: There was a good correlation between the global dermoscopic pattern and findings on the 4 x 4-mm mosaic of confocal images at the level of the dermoepidermal junction. The atypical network correlated with variability in the size and shape of dermal papillae. Globules corresponded with aggregates of bright cells, and darker shades of brown on dermoscopy appeared brighter on RCM. In peripheral streaks, RCM showed dense aggregates of pleomorphic cells of variable brightness and ill-defined cellular borders. These aggregates were continuous with the bright mesh that composed the central bulk of the lesion. A blue-white veil correlated with disruption of the rimmed papillae meshlike pattern and sometimes with the presence of bright cells corresponding to melanophages. CONCLUSION: Correlating dermoscopic structures to RCM features is possible and a necessary step toward understanding the potential benefits of RCM in the clinical setting.     

The spectrum of Spitz nevi: a clinicopathologic study of 83 cases

OBJECTIVE: To achieve a clinicopathologic classification of Spitz nevi by comparing their clinical, dermoscopic, and histopathologic features. DESIGN: Eighty-three cases were independently reviewed by 3 histopathologists and preliminarily classified into classic or desmoplastic Spitz nevus (CDSN, n = 11), pigmented Spitz nevus (PSN, n = 14), Reed nevus (RN, n = 16), or atypical Spitz nevus (ASN, n = 14); the remaining 28 cases were then placed into an intermediate category (pigmented Spitz-Reed nevus, PSRN) because a unanimous diagnosis of either PSN or RN was not reached. SETTING: University dermatology and pathology departments and general hospital pathology departments. PATIENTS: A sample of subjects with excised melanocytic lesions. MAIN OUTCOME MEASURE: Frequency of dermoscopic patterns within the different histopathologic subtypes of Spitz nevi. RESULTS: Overlapping clinical, dermoscopic, and histopathologic findings were observed among PSN, RN, and PSRN, thereby justifying their inclusion into the single PSRN diagnostic category. Asymmetry was the most frequent indicator of histopathologic ASN (79%; n = 11); in only 4 cases did dermoscopic asymmetry show no histopathologic counterpart, and in those cases the discrepancy was probably the result of an artifact of the gross sampling technique carried out with no attention to the dermoscopic features. CONCLUSIONS: Among Spitz nevi, histopathologic distinction between PSN and RN is difficult, not reproducible, and may be clinically useless. A simple clinicopathologic classification of these neoplasms might therefore be structured as CDSN, PSRN, and ASN. Asymmetry should be assessed using both dermoscopic and histopathologic analysis, and reliability in histopathologic diagnosis may be enhanced by the simultaneous evaluation of the corresponding dermoscopic images.     

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.     

Limitations of dermoscopy in the recognition of melanoma

OBJECTIVE: To compare dermoscopic features of melanocytic nevi with those of early melanomas that were not excised initially because of their uncharacteristic clinical and dermoscopic appearance. DESIGN: Retrospective study of the baseline images of 325 melanocytic skin lesions that were observed by digital dermoscopy and finally excised because of changes over time. SETTING: A dermatologic clinic and a dermatologic department at a university hospital. MAIN OUTCOME MEASURES: Comparison of baseline images of melanomas and melanocytic nevi by pattern analysis, the ABCD rule of dermoscopy, and the 7-point checklist. RESULTS: Baseline dermoscopic images of 262 melanocytic nevi and 63 melanomas from 315 patients were included in the analysis. The patterns of dermoscopic features observed in the baseline images of melanocytic lesions finally diagnosed as melanomas during follow-up did not differ substantially from the patterns observed in the baseline images of melanocytic nevi. Pattern analysis, the ABCD rule of dermoscopy, and the 7-point checklist failed to achieve adequate diagnostic accuracy for melanoma. In retrospect, no dermoscopic feature or pattern of features could be identified that reliably differentiated between melanomas and melanocytic nevi at the time of the first presentation. CONCLUSION: Dermoscopy depends on the appearance of classic dermoscopic features and is therefore limited in the diagnosis of very early and mainly featureless melanomas.     

Clinicopathological correlation of pigmented skin lesions using dermoscopy

Dermoscopy (dermatoscopy, epiluminescence microscopy) is an additional measure for making the diagnosis of pigmented skin lesions more accurate. It enables the clinician to visualize features not discernible by the naked eye. By applying enhanced digital dermoscopy and a standardized gross pathology protocol to pigmented skin lesions, a precise clinicopathological correlation of relevant dermoscopic features can be made. Histological specimens of four pigmented skin lesions (melanoma in situ, Clark's nevus, Reed's nevus, seborrheic keratosis) were processed using a standardized gross pathology protocol and viewed along with the clinical photographs and digital dermoscopic images that were magnified and enhanced to better visualize the corresponding dermoscopic structures. Furthermore, measurements of dermoscopic structures using digital equipment were correlated with histometric findings. Our understanding of dermoscopic features, especially the broadened pigment network - a specific dermoscopic criterion for melanoma - was refined by this detailed case-by-case correlation. In addition, some not yet fully characterized dermoscopic features, such as black lamella, radial streaks, and exophytic papillary structures, were described in detail dermoscopically and histopathologically. Moreover, measurements of these dermoscopic features and the underlying histological structures were found to be similar. Linking dermoscopy more closely with cutaneous pathology may help refine the definitions and diagnostic criteria of pigmented skin lesions for dermatologists as well as dermatopathologists.     

Dermoscopic aspects of syringocystadenoma papilliferum associated with nevus sebaceus

Syringocystadenoma papilliferum is a rare benign adnexal tumor that frequently shows apocrine differentiation. It usually develops on the scalp and is associated with a nevus sebaceus in 40% of cases. Although the clinical presentation may differ, its histology is characteristic. Reports have been made of dermoscopy used in cases of adnexal tumors such as eccrine poromas, hidradenomas and angiohistiocytomas; however, up to the present moment there have been no reports of dermoscopy in a case of syringocystadenoma. This paper describes the dermoscopic features found in a case of syringocystadenoma associated with a nevus sebaceus, revealing a polymorphous vascular pattern including a horseshoe-shaped arrangement of vessels.     

Clinical and dermoscopic features of congenital melanocytic nevi

BackgroundCongenital melanocytic nevi (CMN) are nevomelanocytic nevi which are present at birth. In this study, we set out to determine the clinical and dermoscopic properties of CMN.MethodsA total of 239 lesions were diagnosed as CMN. Dermoscopic properties were noted. Age, sex, nevus location and nevus size of the patients were also collected from the patient records.ResultsA total of 239 lesions were diagnosed as CMN in 239 patients (age ranged from 1 month to 63 years (20.79 ± 13.76 yr); 114 [47.7%] males and 125 [52.3%] females). Most of the lesions were medium-sized CMN, followed by small and large ones. The most common localization was upper extremities (23.8%), followed by head and neck, back, and lower extremities respectively. Dark brown was the most common colour seen in dermoscopy (115 patients, 48.1%), followed by light brown (69 patients, 28.9%) and black (55 patients, 23%) respectively. The most common dermoscopic findings of CMN was hair follicles followed by dots (70%) and perifollicular hypopigmentation (51%).ConclusionsOur study describes the normal clinical and dermoscopic features of CMN. It should be kept in mind that, CMNs are quite common lesions, and melanomas can arise from them. Knowing and being familiar with the normal properties of these common nevi will help us determine whether a nevus is suspicious or not.     

反射式共聚焦显微镜联合皮肤镜对黑素细胞痣的诊断价值评估

目的 评估皮肤镜与反射式共聚焦显微镜(RCM)单独或联合对黑素细胞痣的诊断价值.方法 收集临床拟诊黑素细胞痣的患者37例,对皮损先进行皮肤镜、RCM检查,再经组织病理学检查确诊.总结黑素细胞痣的影像学特征,计算不同检查诊断黑素细胞痣的敏感度、特异度、阳性预测值、阴性预测值、正确率,分析皮肤影像技术与组织病理学诊断的一致性.结果 皮肤镜和RCM检查结果示真皮内痣细胞的形态结构可分为两种:(a)真皮乳头层不融合、高折光、圆形的痣细胞,皮肤镜下表现为褐色或浅褐色均质模式,见于5处皮损;(b)真皮乳头内不规则、高折光的痣细胞团块,皮肤镜表现为鹅卵石模式或球状模式,见于31处皮损.在诊断黑素细胞痣方面,RCM结合皮肤镜的敏感度、特异度、正确率、阳性预测值、阴性预测值分别为91.7％、87.5％ 、90.9％ 、97.1％ 、70％,RCM为86.1％ 、75％ 、84％ 、93.9％ 、54.5％,皮肤镜为77.8％ 、87.5％ 、75％ 、96.3％ 、41.2％.除特异度与皮肤镜相同外,RCM结合皮肤镜的其他指标均高于二者单独应用;RCM敏感度、正确率、阴性预测值高于皮肤镜,特异度、阳性预测值低于皮肤镜.RCM结合皮肤镜或单用RCM与组织病理诊断结果之间差异无统计学意义(x2值分别为0.25、0.57,P值分别为0.63、0.45),Kappa值分别为0.72、0.53;皮肤镜与病理诊断结果之间差异有统计学意义(x2=5.81,P=0.012).结论 RCM联合皮肤镜较二者单独使用能更准确地诊断黑素细胞痣.     

Dermoscopic features of congenital melanocytic nevus and Becker nevus in an adult male population: an analysis with a 10-fold magnification

BACKGROUND: Dermoscopic features of congenital melanocytic nevi (CMN) have been mostly assessed by high-resolution video-dermoscopy. However, optical dermoscopy with the 10-fold magnification is largely available. In some instances, the differential diagnosis between large CMN and Becker nevus (BN) may be difficult. OBJECTIVE: The aims of this work were: (1) to assess by dermoscopy with the 10-fold magnification the morphological features which have been previously suggested as useful for the identification of CMN in high-resolution video-dermoscopy; (2) to search and point out the dermoscopic features of BN; (3) to explore dermoscopic differences between CMN and BN. METHODS: The subjects were observed among about 23,000 consecutive young men assessed at the Draft Council's Medical Unit of the Italian Navy in Taranto for compulsory recruitment and referred to the Department of Dermatology of the Italian Navy Hospital for dermatological examination. Lesions were examined by the same observer using a dermatoscope with a 10-fold magnification, and both the dermoscopic criteria stated by the international Consensus Net Meeting on Dermoscopy and dermoscopic features previously suggested as useful for the identification of CMN by video-dermoscopy were recorded in a predisposed patient's card. RESULTS: There were 127 male subjects, median age 19 years, with 127 CMN, measuring > or = 1.5 to < or = 19.9 cm in 78% and > or = 20 cm in 22% of cases, and 64 male subjects, median age 19 years, with 64 BN. In the sample of medium-sized and large CMN, dermoscopic features previously identified as characteristic of congenital lesions (i.e. target network, focal thickening of network lines, target globules, skin furrow hypopigmentation, focal hypopigmentation, hair follicles, perifollicular hypopigmentation, vessels and target vessels) were observed in sufficiently high rates. In the BN group, network, focal hypopigmentation, skin furrow hypopigmentation, hair follicles, perifollicular hypopigmentation and vessels were the main dermoscopic features. Focal thickening of network lines, globules, target globules, homogeneous diffuse pigmentation, hyperpigmented areas, blotches and target vessels were more frequently observed in CMN than in BN. CONCLUSIONS: (1) The same dermoscopic features observed in small and medium-sized CMN by video-dermoscopy with high magnifications are also detectable in medium-sized and large CMN, employing the dermoscopy with the 10-fold magnification. (2) Network, focal, skin furrow and perifollicular hypopigmentation, hair follicles and vessels could be considered as peculiar dermoscopic features of BN. (3) Major differences in the frequency of dermoscopic characteristics were detected between CMN and BN, and dermoscopy seems to provide some diagnostic aid in differentiating CMN from BN in equivocal cases.     

A Case Report on the Dermoscopic Features of Spark's Nevus

Spark''s nevus is a compound word composed of Spitz nevus and Clark''s nevus. It is one of the combined melanocytic nevi which is more common in female and usually presents as a sharp circumscribed hyperpigmented macule on the lower extremities. On histopathologic findings, both cytologic features of Spitz nevus characterized as large spindle or epithelioid melanocytes containing large nuclei with abundant cytoplasm, and architecture of Clark''s nevus characterized as elongation of rete ridges, bridging of the nests, concentric and lamellar fibrosis can be seen. A 24-year-old female presented with an asymptomatic, solitary, dark-brown-colored papule surrounded by brownish patch that looked similar to dysplastic nevus or malignant melanoma on the buttock. On dermoscopic examination, it showed brown-to-black globules, diffuse homogenous pigmentation with blue-white structures, and a surrounding brownish reticular pattern that faded away. On histopathologic findings, overall asymmetrical structure, epithelioid large melanocytes containing large nuclei with abundant cytoplasm, and Kamino body were seen in the central portion. Also, lentiginous hyperplasia, bridging of the nests composed of melanocytes containing foamy cytoplasm, concentric and lamellar fibrosis along with the elongation of rete ridge, and perivascular lymphocytic infiltration were seen in the peripheral portion. The diagnosis of Spark''s nevus was made. Following its definition, this combined nevus is diagnosed histopathologically, but the clinicodermoscopic features have not been well described. Herein, we report a case of Spark''s nevus in which dermoscopy was helpful for differentiating it from malignant melanoma.