Clinically equivocal melanocytic skin lesions with features of regression: a dermoscopic-pathological study

BACKGROUND: Benign melanocytic skin lesions may be difficult to differentiate from melanoma both clinically and dermoscopically. One of the most confounding dermoscopic features, commonly seen in melanoma but in our experience also in melanocytic naevi, is represented by the so-called blue-white structures (BWS). OBJECTIVES: To evaluate diagnostic significance and histopathological correlates of BWS seen by dermoscopy in a series of clinically equivocal melanocytic skin lesions that were excised. METHODS: Patients were recruited from six specialized pigmented lesion clinics in Austria, Italy and Spain over a period of 9 months. All consecutive patients showing one or more melanocytic lesions with BWS, but not classified as melanoma dermoscopically, were included. Each lesion was photographed clinically and dermoscopically. All images were reviewed by one of us and the degree, type and location of BWS evaluated for each lesion. A panel of four experienced dermatopathologists independently reviewed all specimens for diagnosis and one of them evaluated presence and degree of melanosis and/or fibrosis. The main outcome measures were the percentage and histopathological correlates of lesions with different degree, type and location of BWS. RESULTS: All included lesions with BWS (n = 158) showed partial or focal regression histopathologically. One hundred and thirty-five (85.4%) lesions were diagnosed as melanocytic naevi (complete histopathological interobserver agreement), whereas 23 (14.6%) were defined as equivocal because at least one of four pathologists diagnosed the given lesion as melanoma. Only one lesion was diagnosed as melanoma by all four pathologists. The majority of naevi exhibited blue areas (84.4%) with a central distribution (57%) and involving < 50% of the lesion surface (89.6%). By contrast, 78.3% of equivocal lesions revealed a combination of white and blue areas with an irregular distribution (60.9%) and involving > 50% of the lesion surface (47.8%). CONCLUSIONS: Using degree and type of BWS, an algorithm was constructed that can be applied for the management of lesions exhibiting dermoscopic features of regression.     

Diagnostic ability of general practitioners and dermatologists in discriminating pigmented skin lesions

BACKGROUND: Early recognition of melanoma is the key in preventing metastatic disease. OBJECTIVE: The aim of this study was to evaluate diagnostic ability of general practitioners (GPs) and dermatologists concerning pigmented skin lesions in general and melanoma in particular. We also investigated whether the diagnostic ability of GPs changed after a lecture on melanoma. METHODS: A test set of 13 pigmented skin lesions on 35-mm color slides was presented to 160 GPs and 60 dermatologists during educational courses. RESULTS: GPs correctly evaluated biologic behavior of the pigmented skin lesions in 72% of the evaluations. In 71% of these evaluations they correctly identified the lesions. The proportion of lesions correctly identified was positively correlated with the frequency of pigmented skin lesions in everyday practice. Dermatologists made a correct identification of the lesions in 88% of all evaluations, and they correctly evaluated biologic behavior in 94% of these. Recognition of melanoma was proportional to melanoma exposure in everyday practice. Thick melanomas were better recognized than thin melanomas in both physician groups. After a lecture on melanoma, sensitivity of GPs to recognize malignant disease increased from 72% to 84%, without a significant decrease in specificity. The proportion of lesions correctly identified also rose significantly (66% vs 52%).     

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     

Objective follow-up of atypical melanocytic skin lesions: a retrospective study

Various authors have suggested that information from longitudinal observation (follow-up) of dynamic changes in atypical melanocytic pigmented skin lesions (MPSL) could enable identification of early malignant melanoma escaping initial observation due to an absence of specific clinical and dermoscopic features. The aim of our retrospective study was to determine the existence of numerical variables regarding changes in MPSL that could be useful to differentiate early melanomas and atypical nevi. The study was carried out in two Italian dermatology Centres. Digital dermoscopy analyzers (DB-Mips System) were used to evaluate dermoscopic images of 94 equivocal pigmented skin lesions under observation for 6–12 months and then excised because of changes across time (29 melanomas and 65 nevi). The analyzer evaluates 49 parameters grouped into four categories: geometries, colours, textures and islands of colour. The ROC curve designed on the 49 digital dermoscopy analysis parameters showed good accuracy. At sensitivity (SE) = specificity (SP), it correctly classified 89.3% of cases. When objective pigmented skin lesion parameters were considered together with their objective changes over 6–12 months, a decisive increase in discrimination capacity was obtained. At SE = SP accuracy was 96.3%. Analysis of the parameters of our model and statistical analysis enabled us to interpret/identify the most significant factors of modification and differentiation of lesions, providing quantitative insights into the diagnosis of equivocal MPSL and demonstrating the utility of objective/numerical follow-up.     

Morphologic changes of pigmented skin lesions: a useful extension of the ABCD rule for dermatoscopy

BACKGROUND: Epiluminescence microscopy (ELM) significantly increases the early diagnosis of pigmented skin lesions (PSL) using established criteria and pattern analysis. The ABCD rule for dermatoscopy (ie, ELM) provides a simplified approach to the interpretation of ELM images on the basis of asymmetry (A), border (B), color (C), and dermatoscopic structure (D). OBJECTIVE: We set out to determine whether the diagnostic accuracy of the ABCD scoring algorithm can be significantly improved by incorporating information about morphologic changes of the lesion observed and provided by the patient. METHODS: We prospectively collected 356 small pigmented skin lesions (< 1 cm) including 73 (20.5%) melanomas. Before excision all patients were asked whether the lesion had changed in size, color, or shape within the last year or whether they experienced any sign of ulceration or spontaneous bleeding. ELM images of the lesions were evaluated according to the ABCD rule for dermatoscopy to yield a semiquantitative score. Accuracy of diagnosis was evaluated in terms of sensitivity, specificity, and area under receiver operating characteristic curves (AUC). RESULTS: The frequency of reported changes was significantly higher for melanomas than benign PSL (65.8% vs 29.7%, P < .001). In a multivariate model morphologic change was a significant independent predictor of malignancy (odds ratio = 3.17, 95% confidence interval [CI]: 1.96 to 5.14, P < .001). The mean final score achieved when using the enhanced ABCD-E criteria including morphologic change (E) was significantly higher for melanomas (5.7, 95% CI: 5.3 to 6.0) than benign PSL (2.9, 95% CI: 2.8 to 3.1, P < .001). Diagnostic accuracy was significantly higher when the lesions were evaluated by the enhanced ABCD-E criteria as compared with the standard ABCD score (AUC(ABCD) = 0.87 vs AUC(ABCD-E) = 0.90; P = .006). CONCLUSION: Information about morphologic changes of PSL as reported by the patient is a useful extension of the ABCD rule for dermatoscopy.     

Computer-based classification of dermoscopy images of melanocytic lesions on acral volar skin

We describe a fully automated system for the classification of acral volar melanomas. We used a total of 213 acral dermoscopy images (176 nevi and 37 melanomas). Our automatic tumor area extraction algorithm successfully extracted the tumor in 199 cases (169 nevi and 30 melanomas), and we developed a diagnostic classifier using these images. Our linear classifier achieved a sensitivity (SE) of 100%, a specificity (SP) of 95.9%, and an area under the receiver operating characteristic curve (AUC) of 0.993 using a leave-one-out cross-validation strategy (81.1% SE, 92.1% SP; considering 14 unsuccessful extraction cases as false classification). In addition, we developed three pattern detectors for typical dermoscopic structures such as parallel ridge, parallel furrow, and fibrillar patterns. These also achieved good detection accuracy as indicated by their AUC values: 0.985, 0.931, and 0.890, respectively. The features used in the melanoma-nevus classifier and the parallel ridge detector have significant overlap.     

The effect of an educational programme to improve the skills of general practitioners in diagnosing melanocytic/pigmented lesions

BACKGROUND: Skin cancer is a major public health issue in fair-skinned populations, and general practitioners (GPs) play an important role in the diagnosis and management of this disease. AIMS. To evaluate a self-instructional education module with audit and feedback, designed to increase the skills of GPs in diagnosing melanocytic lesions and skin cancer. METHODS. This study, conducted in Queensland, Australia, included 16 GPs who participated in an 18-month programme, comprising a 6-month baseline audit of skin excisions, a 6-month educational programme and a 6-month posteducation audit. RESULTS. The overall diagnostic accuracy of malignant lesions was 63.2% (95% CI 60.0-66.3) during baseline and 64.5% (95% CI 61.1-67.7) posteducation. Significant improvements were seen posteducation in the proportion of melanocytic lesions confirmed as malignant (6.1% baseline and 13.5% posteducation, chi(2) = 6.6, P = 0.01). GPs with < 15 years of practice recorded significantly lower levels of diagnostic accuracy at baseline compared with those with >/= 25 years of practice (P = 0.001). There were no differences in diagnostic skill posteducation according to years of practice. CONCLUSIONS. The education programme improved the malignant : benign ratio of melanocytic lesions, resulting in a doubling in the number of melanomas diagnosed. We found that GPs with less experience benefited most from the programme, indicating that tailoring of programmes to individual skills and years of practice might be beneficial.     

Dermoscopic monitoring of melanocytic skin lesions: clinical outcome and patient compliance vary according to follow-up protocols

Background  Dermoscopic monitoring of melanocytic lesions increases the likelihood that featureless melanomas are not overlooked and minimizes the excision of benign lesions.
Objective  To examine clinical outcome and patient compliance using different follow-up protocols.
Methods  A retrospective analysis of 600 lesions from 405 patients (aged 6–79 years) was performed to examine patient compliance and clinical outcome in patients with multiple atypical melanocytic lesions undergoing sequential dermoscopy imaging during short-, medium- or long-term follow-up. Based on the degree of dermoscopic atypical features, patients were scheduled for short-term monitoring with follow-up after 3 months, medium-term monitoring with follow-up after 6 months or long-term monitoring with annual follow-up. Criteria leading to excision of monitored lesions differed according to the follow-up protocol.
Results  In a median follow-up period of 23 months, 54 (9%) lesions were excised, revealing 12 early melanomas (occurring in 3% of monitored patients), one basal cell carcinoma and 41 melanocytic naevi. The melanoma/benign ratio of excised lesions was 1 : 3·4. Seven of 12 melanomas showed changes after two to four visits, corresponding to 8–54 months of follow-up. Patient compliance was 84% for short-term monitoring, 63% for medium-term monitoring and 30% for long-term monitoring.
Conclusions  In patients with multiple naevi sequential dermoscopy imaging is a useful strategy to avoid missing melanomas while minimizing unnecessary excision of benign lesions. For better compliance, the first re-examination should be scheduled at 3 months after the baseline visit. Regular annual follow-up monitoring is also needed to detect slow-growing melanomas in which subtle changes may become apparent only over time.     

The impact of dermoscopy on the management of pigmented lesions in everyday clinical practice of general dermatologists: a prospective study

Background Dermoscopy greatly improves the clinical diagnosis of pigmented lesions. Few studies have investigated, however, how dermoscopy is guiding management decisions in everyday clinical practice. In addition, most studies have been performed in the setting of dermoscopy experts working in pigmented lesion clinics. Objectives To assess the impact of dermoscopy on clinical diagnosis and management decisions for pigmented lesions in everyday practice of general dermatologists. Methods We performed a prospective study in general dermatology clinics in community hospitals run by dermatologists with intermediate dermoscopy experience and expertise. Each clinician independently included suspicious lesions from consecutive patients. Pre‐ and postdermoscopy diagnoses and management decisions were recorded. Pathology was used as reference diagnosis. Results In total, 209 suspicious lesions were included in the study by 17 dermatologists. Fourteen lesions were histologically proven in situ or invasive malignant melanomas. Based on clinical diagnoses, dermoscopy improved sensitivity from 0·79 to 0·86 (P = 1·0). All 14 melanomas were intended to be excised based on naked eye examination alone, independent of dermoscopic evaluation. Specificity increased from 0·96 to 0·98 (P = 0·22). Dermoscopy resulted in a 9% reduction of the number of excisions. Conclusions Dermoscopy reduced the number of excisions, but did not improve the detection of melanomas. Our results suggest that in everyday clinical practice of general dermatologists the main contribution of dermoscopy is a reduction of unnecessary excisions.     

Immunohistochemical detectability of cyclooxygenase-2 expression in cells of human melanocytic skin lesions: A methodological review

Increased cyclooxygenase-2 (COX-2) expression is thought to support tumorigenesis through various mechanisms and is analyzed as a potential cancer marker. In 18 studies, COX-2 expression in melanocytic lesions of human skin was examined immunohistochemically. However, results obtained by individual research groups differ in terms of detection frequency and level of this protein, as well as localization of stained cells within tumor. Possible reasons for the discrepancies are analyzed in this review: the application of different antibodies, the use of standard histopathological sections or tissue microarrays and the analyzes of staining results based on different algorithms. COX-2 level is significantly lower in nevi than in melanomas, increases gradually with progression of these malignant cancers and reaches the highest values in metastases. These gradual changes in COX-2 expression appear to be difficult to analyze based only on subjective assessment of staining intensity. The most convergent data were obtained using antibodies for N-terminal fragments of COX-2 protein and analyzing results based on calculation of percentage fraction of positive cells. The extent of stained area in specimen thus appears to be more important than the intensity of staining in terms of evaluation of COX-2 performance as a diagnostic and prognostic marker of cutaneous melanoma.