Dysplastic naevus vs. in situ melanoma: digital dermoscopy analysis.

BACKGROUND: To date, much confusion exists about the biological significance of dysplastic naevi and about the relationship between melanocytic dysplasia and clinical atypia. OBJECTIVES: To use a digital dermoscopy analyser with a series of 'borderline' pigmented skin lesions (i.e. dysplastic naevi and in situ melanomas) to find correlation between the studied variables and to determine their discriminating power with respect to histological diagnosis. METHODS: The pigmented skin lesions (n = 174) were histologically examined by three experienced dermatopathologists and identified as in situ melanomas (n = 38) and dysplastic naevi (n = 136). The system evaluated 48 parameters as possible discriminant variables, grouped into four categories: geometry, colours, textures and islands of colour. Once the lesions were analysed (stepwise discriminant analysis), sensitivity, specificity and accuracy were calculated. RESULTS: At the end of the stepwise procedure the percentage of cases classified correctly was 71.8%. Of 136 dysplastic naevi only 98 were classified correctly, while 27 of 38 in situ melanomas were recognized correctly. CONCLUSIONS: We conclude that there are so far no digital dermoscopic criteria that can clearly distinguish dysplastic naevi from in situ melanomas.

The 'common mole' from the point of view of digital dermoscopy analysis: subjective vs. objective evaluation of easy pigmented skin lesions.

BACKGROUND: The term 'common mole', often used to describe a subset of benign pigmented skin lesions, is traditionally defined on the basis of morpho-chromatic features. In recent years, certain research groups have developed equipment and methods, such as digital dermoscopy analysis, that enable objective evaluation of pigmented skin lesions. OBJECTIVE: In this study we use a digital dermoscopy analyser trained for the recognition of pigmented skin lesions to compare the subjective definition of 'common' and the mathematical concept of 'close to the mean of measurements'. METHODS: A subset (100) of digital images of flat pigmented lesions, obtained in daily practice, were classified by trained and non-expert clinicians as common moles (60) or clear-cut melanoma (40), and processed with a DB-Mips analyser. The resulting parameters, validated by a classifier, were used to evaluate Hotelling's T2 multivariate distances from the mean. RESULTS: 'Common' moles could not be clearly defined in terms of closeness to the means of objectively evaluated parameters. Their diagnosis indudes many other evaluations and clusters of variables. CONCLUSION: The clinical semantics of the term 'common' does not conform to any unambiguous mathematical definition.

Digital dermoscopy analysis of atypical pigmented skin lesions: a stepwise logistic discriminant analysis approach.

BACKGROUND: Digital microscopy is a non-invasive diagnostic technique enabling determination of characteristics that cannot be appreciated by direct observation. If correctly applied, this technique can be useful for the diagnosis of pigmented skin lesions. PURPOSE: To evaluate the utility of digital microscopy for analysing atypical benign and malignant pigmented skin lesions exploiting digital numerical filtering and automatic measurements. METHODS: Forty-eight parameters were identified as possible discriminating variables, and were grouped in four categories: geometries, colours, textures, and islands of colour. Statistical analysis was used to identify the variables with the highest discriminating power. RESULTS: The high quality of the digital image made it possible to observe diagnostic signs in pigmented skin lesion images, acquired by the present technique, in great detail. Specially designed filtering enhanced certain diagnostic patterns. Stepwise discriminant analysis selected only 10 variables (the means of these variables were higher in melanomas than in nevi). CONCLUSIONS: The combined use of digital dermoscopy and stepwise logistic discriminant analysis made it possible to single out the best objective variables for distinguishing atypical nevi and early melanoma.

Differentiation between pigmented Spitz naevus and melanoma by digital dermoscopy and stepwise logistic discriminant analysis.

Epiluminescence light microscopy (ELM) has proven useful in the diagnosis of pigmented skin lesions (PSLs). However, in some cases this technique does not sufficiently increase the diagnostic accuracy in distinguishing pigmented Spitz naevi (PSNs) from melanoma. With the aim of obviating these problems of qualitative interpretation, methods based on the mathematical analysis of PSLs, such as digital dermoscopy analysis (DDA), have recently been developed. In the present study we used a digital dermoscope (DBDermo-MIPS, Dell'Eva-Burroni) to analyse PSNs and melanomas with similar clinical and dermoscopic features for any correlation between variables and to determine its discriminating power with respect to histological diagnosis. The 100 lesions underwent histological examination by three experienced dermatopathologists and were identified as PSNs (43) or melanomas (57). Thirty-six parameters were identified as possible discriminating variables and were grouped in four categories: geometry, colour, texture, and islands of colour. Statistical analysis was used to identify the variables with the highest discriminating power. Stepwise discriminant analysis selected only four variables: entropy, minimum diameter, red lesion value and peripheral dark (the means of these variables were higher in melanomas than in PSNs). Thus the combined use of digital dermoscopy and stepwise logistic discriminant analysis made it possible to single out the best objective variables for distinguishing PSN and melanoma.

Digital epiluminescence microscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions. A statistical comparison between visual and computer inspection.

Epiluminescence light microscopy (ELM) has been confirmed to be a useful tool for the diagnosis of pigmented skin lesions. The application of digital systems to epiluminescence represents the latest attempt to improve the diagnosis of cutaneous melanoma. The aim of this study was to compare the diagnostic accuracy of one of these systems, the DB-Dermo MIPS, with the accuracy of well-trained dermatologists using the ELM technique in order to establish the real usefulness of this instrument and to verify how much it can help the clinician make a diagnosis in a clinical setting. During a campaign for the early diagnosis of cutaneous melanoma, 311 patients with non-melanocytic lesions, common naevi, dysplastic naevi and melanomas underwent clinical diagnosis using ELM, computerized evaluation with DB-Dermo MIPS and skin biopsy. Sensitivity, specificity, true and negative predictive value were evaluated for epiluminescence and digital epiluminescence. Our study revealed that the inspection of pigmented skin lesions by digital epiluminescence has a better diagnostic accuracy than that of a trained dermatologist using the epiluminescence technique only. In our experience, this computerized system can play an essential role in the detection of early melanomas.

Digital dermoscopy analysis for the differentiation of atypical nevi and early melanoma: a new quantitative semiology.

OBJECTIVES: To use a digital dermoscopy analyzer with a series of "borderline" pigmentary skin lesions (ie, clinically atypical nevi and early melanoma) to find correlation between the studied variables and to determine their discriminating power with respect to histological diagnosis. DESIGN: A total of 147 pigmentary skin lesions were histologically examined by 3 experienced dermatopathologists and identified as nevi (n = 90) and melanomas (n = 57). The system evaluated 36 variables to be studied as possible discriminant variables, grouped into 4 categories: geometries, colors, textures, and islands of color. SETTING: University medical department. PATIENTS: A sample of patients with excised pigmentary skin lesions (nevi and melanomas). MAIN OUTCOME MEASURES: Sensitivity, specificity, and accuracy of the model for evaluating "borderline" pigmentary skin lesions. RESULTS: After multivariate stepwise discriminant analysis, only 13 variables were selected to compute the canonical discriminant function. CONCLUSION: The present method made it possible to determine which objective variables are important for distinguishing atypical benign pigmentary skin lesions and early melanoma.

Face-to-face diagnosis vs telediagnosis of pigmented skin tumors: a teledermoscopic study.

BACKGROUND: Teledermoscopy uses telecommunication technologies to transfer images of pigmented skin lesions, including clinical and anamnestic data, via e-mail to specialized centers for teleconsultation. DESIGN: Sixty-six pigmented skin lesions examined on a face-to-face basis in a skin lesion clinic in L'Aquila, Italy, were sent via e-mail on a standard-resolution color monitor for consultation at a university dermatology department in Graz, Austria. INTERVENTION: Digital photographs of the clinical and dermoscopic images of all pigmented tumors were taken with a stereomicroscope connected to a high-resolution video camera in Truevision advanced graphic array (Targa) format file and converted successively into a Joint Photographic Expert Group (PEG) format file. All lesions were excised surgically and diagnosed histopathologically. MAIN OUTCOME MEASURE: Diagnostic concordance between face-to-face diagnosis and telediagnosis. RESULTS: The diagnostic concordance was 60 (91%) of 66 cases. The number of correct telediagnoses was lower, but the difference was not statistically significant (Wilcoxon test, P = .10). The accuracy of the telediagnoses was not related to the quality of the images, but highly depended on the level of diagnostic difficulty of a given pigmented skin tumor (Spearman correlation, P= .01). CONCLUSION: Teleconsultation of clinical and dermoscopic images of skin tumors via e-mail provides a similar degree of diagnostic accuracy as face-to-face diagnosis.

Computerized evaluation of pigmented skin lesion images recorded by a videomicroscope: comparison between polarizing mode observation and oil/slide mode observation.

BACKGROUND/AIMS: It has now been established that ELM significantly improves the clinical diagnosis of pigmented skin lesions, particularly when associated with image analysis on digital pictures. Besides surface microscopes, so called "videomicroscopes" are nowadays commercially available. Thanks to their practicality and to their reasonable price and small volume, they could be usefully employed by general practitioners or peripheral dermatologists in their practice. The aim of our study was to evaluate the usefulness and the handiness of a videomicroscope provided with polarized light, and to compare images recorded in the polarizing mode to those of the same lesions recorded after application of oil and a glass slide. METHODS: 114 images of benign pigmented skin lesions were recorded both in polarizing mode and in oil/slide mode observation. Digital images were then analyzed by means of a dedicated software, evaluating 34 different parameters. RESULTS: The instrument is easy to handle and the acquisition of images is simple and quick. Polarizing mode observation enables the recognition of subsurface structures, like pigment network and capillaries. Red and blue components in the images tend to be more pronounced, when images are acquired by the polarizing system, whereas green components are prominent in oil images. Values referring to dark areas are also higher for oil images. However, the 2 observation modes provide digital images, whose values, in most cases, do not differ statistically. CONCLUSION: Videomicroscopes are cheap, space saving, and enable a quick examination of skin areas to be imaged. The possibility of a rapid switch from surface to subsurface polarizing mode observation, makes the examination procedure even faster. Our data demonstrate that polarizing mode observation and recording can be employed as a basis for clinical and computerized epiluminescence, particularly in situations, where a rapid screening of numerous patients and lesions is necessary.