Typical dermoscopic patterns of benign melanocytic nevi

Dermoscopy often is an effective diagnostic tool for differentiating benign and malignant pigmented skin lesions. The observed dermoscopic structures and patterns of lesions provide valuable sources of information that are not accessible by routine clinical examination. Recognition and interpretation of these dermoscopic structures and patterns require training and experience. Mentioned here are some fundamental guidelines for differentiating malignant and benign lesions. Some of the classic patterns associated with a list of benign melanocytic nevi also have been illustrated. Additional research is needed to identify other patterns of these benign lesions. More importantly, analysis of the prevalence of various patterns associated with the various benign lesions will be helpful to clinicians having the responsibility of making in vivo diagnoses of benign compared with malignant melanocytic neoplasms.     

Benign dermoscopic network patterns in dysplastic melanocytic nevi

Background/aims: Epiluminescence microscopy (ELM) is a non-invasive clinical technique, which by employing the optical phenomenon of oil immersion makes surface structures of the skin accessible for in vivo examination and provides additional criteria for the diagnosis of pigment skin lesions (PSLs). Many ELM criteria have been described. One of the most important ELM criteria is the pigment network (PN).
Objective: The aim of this study is to identify benign ELM (dermoscopic) network patterns of dysplastic melanocytic nevi (DMN).
Methods: This study included 907 dysplastic melanocytic nevi in 178 patients. Prior to biopsy, each lesion was photographed with oil immersion, and the images were viewed on a high-resolution compact slide projector. For each PSL, the ELM Network Features and ABCD-score were evaluated.
Results and discussion: The benign dermoscopic network features in DMN are the presents of a regular PN with delicate lines and margins, which predominantly thins out at the border of the lesion. For DMN, with these features, the mean ABCD score is smaller than ABCD-score for DMNs with irregular, prominent PN and network patches, ending abruptly at the periphery. In DMN with a network predominantly thinning out at the border of the lesion several uniform network patterns were found—diffuse network pattern, patchy network pattern, structureless center pattern, globular center pattern, and pigmented-blotch center pattern.
Conclusions: Benign features of pigment network are regularity, delicacy and thinning out at the border of the lesion. Benign dermoscopic network patterns are diffuse network pattern, patchy network pattern, structureless center pattern, globular center pattern, and pigmented-blotch center pattern. They can be found in DMN with a network predominantly thinning out at the border of the lesion.     

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.     

Age- and site-specific variation in the dermoscopic patterns of congenital melanocytic nevi: an aid to accurate classification and assessment of melanocytic nevi

OBJECTIVES: To describe the dermoscopic features of congenital melanocytic nevi (CMN) and assess whether predominant dermoscopic patterns present in CMN are related to an individual's age (<12 years vs >or=12 years), sex, or lesional site (head, neck, and trunk vs extremities). DESIGN: Nonrandomized observational study. PATIENTS: A total of 77 consecutive patients, each with 1 CMN (n = 77 lesions), from an outpatient dermatology clinic. A diagnosis of CMN was established by (1) documentation of a melanocytic nevus during the first year of life or (2) by clinical examination and either clinical history or biopsy findings. MAIN OUTCOME MEASURES: Images of CMN were evaluated for specific dermoscopic structures and patterns. The distribution of patterns was assessed by age, sex, and lesional site. RESULTS: Most of the 77 lesions exhibited 1 of the following predominant dermoscopic patterns: reticular (18 lesions [23%]), globular (14 [18%]), or reticuloglobular (12 [16%]). Globular CMN were present in 5 of the 19 individuals who were younger than 12 years (26%) but in only 9 of the 58 individuals 12 years or older (16%). Reticular CMN were seen exclusively in the individuals who were 12 years or older. Congenital melanocytic nevi exhibiting no predominant pattern were more commonly present in the individuals younger than 12 years. Globular CMN were present in 11 head, neck, and trunk lesions (30%) compared with 3 extremity lesions (8%). Conversely, reticular CMN were present in 16 extremity lesions (40%) compared with 2 head, neck, and trunk lesions (5%). The predominant dermoscopic pattern did not vary based on sex. The most commonly observed dermoscopic structures were globules (in 64 lesions [83%]), hypertrichosis (in 61 [79%]), and reticular networks (in 55 [71%]). CONCLUSIONS: Our results suggest that the predominant dermoscopic patterns of CMN vary according to age and lesional site. These differences may inform future studies on the pathogenesis of CMN.     

Three years dermoscopic follow‐up of atypical nevi

Atypical nevi are dynamic lesions and may progressively transform into more or less atypical lesions. We aimed to investigate the dermoscopic features of atypical nevi and dynamic changes in these lesions over a period of 3‐years. Patients with 3‐year dermoscopic follow‐up records were enrolled in the study. We compared the dermatoscopic features of the nevus recorded in the first dermoscopic examination and at the end of the third year. Changes in size (mm), pattern, and color were investigated. The most common dermoscopic patterns were reticular (18 patients; 34%), reticular‐homogeneous (17 patients; 32.1%), and reticular‐globular (7 patients; 13.2%). The most common pigmentation patterns were central hyperpigmentation (28 patients; 52.8%), regular pigmentation (nine patients; 17.0%), and multifocal hypo/hyperpigmentation (eight patients; 15.1%). Twenty‐one (39.6%) patients showed changes in pattern. The transformation from reticular‐homogeneous pattern to the homogeneous pattern was the most frequent change in pattern (7 of 21 patients; 33.3%). The transformation from reticular pattern to reticular‐homogeneous pattern was the second most common change in pattern (5 of 21 patients; 23.8%). Fourteen (26.4%) patients experienced symmetrical enlargement. Symmetrical enlargement was statistically more frequent in patients who showed dermoscopic changes in pattern than in those who did not show any changes in the pattern (p: .038). In this study, we did not observe any new dermoscopic clues for the diagnosis of melanoma during the follow‐up. The nevi tended to turn into a homogeneous (structureless) pattern. We observed that the most common dermoscopic change in pattern was the transformation from reticular‐homogeneous pattern to homogeneous pattern, and the lesions had symmetrical enlargement during this transformation. In conclusion, despite the known association between atypical nevi and the risk of developing melanoma, most atypical nevi do not transform into melanoma. Therefore, our study suggests that the excision of atypical nevi is not necessary and dermatoscopic follow‐up can reduce the number of unnecessary excisions.     

Influence of PUVA therapy on dermoscopic features of acquired melanocytic nevi

The aim of the present study was to investigate whether PUVA therapy can induce changes in the dermoscopic image of acquired melanocytic nevi. In this study, 28 acquired melanocytic nevi of 14 patients undergoing PUVA therapy were examined. Two nevi of morphologically similar features were selected in each patient. During UVA radiation, 14 nevi were protected from UVA exposure and 14 nevi were left unprotected. Before and after 3 months of PUVA therapy, all nevi were documented under standardized conditions by means of a Dermaphot apparatus. Color dermoscopic images of all nevi were examined by two investigators for size, color and structural features (pigment network-streaks, brown globules, black dots). After PUVA therapy, an increase in size (p < 0.05 in protected nevi and p < 0.01 in unprotected nevi) and a general color darkening (p < 0.01 for both groups) were documented in both groups. While significant structural changes (broadness of pigment network, formation of focal branched streaks, increasing in number and size of brown globules) were detected in unprotected nevi (p < 0.05), no significant changes were in protected nevi (p > 0.05).     

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.     

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.     

Follow-up of melanocytic skin lesions with digital epiluminescence microscopy: patterns of modifications observed in early melanoma, atypical nevi, and common nevi

BACKGROUND: Digital epiluminescence microscopy (DELM) has been reported to be a useful technique for the follow-up of melanocytic nevi. One of the promises of this technique is to identify modifications over time that indicate impending or incipient malignancy and to facilitate surveillance of melanocytic skin lesions, particularly in patients with multiple clinically atypical nevi. OBJECTIVE: Our purpose was to report on patterns of modifications over time observed in benign melanocytic skin lesions and melanoma. METHODS: A total of 1862 sequentially recorded DELM images of melanocytic lesions from 202 patients (mean age, 36.1 years; 54.0% female patients) with multiple clinically atypical nevi were included in the analysis. The median follow-up interval was 12. 6 months. Melanocytic lesions with substantial modifications over time (enlargement, changes in shape, regression, color changes or appearance of ELM structures known to be associated with melanoma) were excised and referred to histopathologic examination. RESULTS: A total of 75 melanocytic skin lesions (4.0%) from 52 patients (mean age, 33.3 years; 63.5% female patients) showed substantial modifications over time and were excised and referred to histopathologic examination. Eight changing lesions were histologically diagnosed as early melanomas. These lesions frequently showed focal enlargement associated with a change in shape as well as appearance of ELM structures that are known to be associated with melanoma. In contrast, the majority of benign changing lesions (common and atypical nevi) showed symmetric enlargement without substantial structural ELM changes. Six of the 8 patients in whom melanoma developed were unaware of the fact that the lesion had changed over time. CONCLUSION: We demonstrate that follow-up of melanocytic lesions with DELM helps to identify patterns of morphologic modifications typical for early melanoma. DELM may therefore serve as a useful tool to improve the surveillance of patients with multiple atypical nevi.     

皮肤镜表现为红色均质模式的Spitz痣一例

19岁女性患者,右乳下缘红棕色斑块10余年,逐渐增大。皮肤镜检查:中央均质暗红色区域,可见白色晶状体结构,周边对称分布网状色素沉着和色素条纹向四周呈放射状排列。皮损组织病理示:表皮和真皮可见大量梭形细胞和上皮样黑素细胞组成的瘤细胞巢,具有典型收缩间隙,周围炎性细胞浸润。诊断:Spitz痣。