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At least 469 records · Page 26Linked to original sources
PubMed2006

Acral melanoma simulating warts: dermoscopic clues to prevent missing a melanoma.

BACKGROUND: Acral melanoma may adopt a variety of clinical characteristics simulating other tumors, ulcers, hemorrhage, or infections. In the Caucasian population health care providers often misdiagnose acral melanoma, and this is the cause of inadequate treatments. Clinical and dermoscopic clues can be easily recognized, which help to prevent missing a melanoma. OBJECTIVES: To study the clinical and dermoscopic findings in three cases of acral melanoma simulating warts that had been treated by dermatologists with curettage and cryotherapy. MATERIAL AND METHODS: Clinical and dermoscopic study of the tumors and review of the most frequent simulators of acral melanoma reported in the literature. RESULTS: In all three tumors, hyperkeratosis and the lack of specific pigmentation were observed. The parallel ridge pattern, revealed by dermoscopic examination, precipitated the recognition of acral melanoma. CONCLUSION: In these cases that presented atypical characteristics of acral lesions, therefore challenging the diagnostic process, dermoscopic examination helped to confirm an accurate diagnosis of acral melanoma.

Aged↗
PubMed2006

Regression of atypical nevus: an anecdotal dermoscopic observation.

BACKGROUND: Clark nevi (atypical melanocytic nevi) can be considered as risk markers and potential precursors of melanoma. The authors report on the morphologic changes of an atypical nevus by dermoscopic follow-up examination over a 7-year period. CASE REPORT: A 43-year-old man had a brown macule on his back, sized 5 mm, with an irregular shape, clinically and dermoscopically diagnosed as an equivocal melanocytic lesion. Dermoscopically during the initial examination, a predominant reticular pattern with peripheral eccentric hyperpigmentation in the lower portion of the lesion could be seen. After 7 months, the area of peripheral eccentric hyperpigmentation had regressed, and after 4.5 years the atypical pigment network had almost disappeared. After 7 years of follow-up, a diffuse area of hypopigmentation and a residual light brown pigmentation were detectable. The histopathologic diagnosis was consistent with an atypical junctional nevus with regression with features of a Clark nevus. CONCLUSION: Based on our observation, even a dermoscopically atypical nevus may undergo regression as documented by long-term dermoscopic follow-up.

Adult↗
PubMed2006

Hypoepiluminescence microscopy of pigmented skin lesions: new approach to improve recognition of dermoscopic structures.

BACKGROUND: Hypoepiluminescence microscopy (HELM) is a new dermoscopic approach for analysis of pigmented skin lesions (PSLs) after surgical excision. OBJECTIVES: The objective was to verify whether this method could provide additional morphologic information for diagnostic or didactic purposes compared to conventional epiluminescence microscopy (ELM). PATIENTS AND METHODS: Thirty-one PSLs from 30 patients were consecutively evaluated by ELM and, after excision, by HELM. For HELM examination, the lesion was positioned on a glass slide and illuminated from above with a halogen lamp and from underneath with an LED source. All lesions were subsequently examined histopathologically. RESULTS: In 11 of 31 (35.5%) lesions, a typical pigment network, as assessed by ELM, appeared bidimensional with HELM. In 9 lesions (9/31; 29%) ELM showed a gray-blue area, while HELM allowed us to distinguish 5 lesions (5/9, 55.5%) with gray area predominant showing a lichenoid lymphocytic infiltration and few melanophages from the other 4 lesions (4/9, 44,5%) with heavy dermal accumulation of pigmented melanocytes or melanophages where a blue area was clearly visible at HELM. In 9 other cases (29%), ELM analysis revealed a central homogeneous dark brown/black pigmentation that in 7 cases was seen under HELM examination to consist of globules. CONCLUSIONS: HELM is particularly useful in evaluating heavily PSLs or structures located in the reticular dermis.

Adolescent↗
PubMed2006

Are melanocytic nevi influenced by pregnancy? A dermoscopic evaluation.

BACKGROUND: Dermoscopic data of melanocytic nevi (MN) in pregnancy are very limited and related to small groups of women. OBJECTIVE: This study systematically analyzes dermoscopic parameters in a wide series of MN during and after pregnancy. METHODS: Eighty-six MN on the back of 47 women were studied. Dermoscopic parameters, total dermoscopic score (TDS) according to Stolz's ABCD rule, and the sizes of the nevi were evaluated over time. RESULTS: Progressive lightening of the nevi resulted at the end of pregnancy (p<.05) and after delivery (p<.001). Pigment network showed a progressive reduction in prominence and thickness (end of pregnancy, p<.05; after delivery, p<.01). At the end of pregnancy, vessels increased (p<.05) and a higher TDS was observed, with a significant reduction in both after delivery (vessels, p<.05; TDS, p<.01). Area changes were not statistically significant. CONCLUSIONS: At the end of pregnancy, both vascular structures and TDS increased. These modifications were transient as the nevi recovered their prior appearance after delivery. The results indicate that an intrinsic influence of pregnancy may induce structural modifications without influencing the size of the nevi. Behavioral factors during the observational period, like a reduced exposure to sunlight reported by most of the women, may have influenced other characteristics, like global pigmentation and pigment network. The authors thank the Fondazione Cassa di Risparmio di Ferrara for its financial support, which enabled them to acquire the instrumentation necessary for this study.

Adult↗
PubMed2007

Dermoscopic features of difficult melanoma.

BACKGROUND: The dermoscopic diagnosis of cutaneous melanoma (CM) may be difficult because some CM lack specific dermoscopic features for melanoma diagnosis. OBJECTIVE: To evaluate whether a diagnosis of CM could be achieved using the classic dermoscopic melanoma-specific criteria, we conducted a retrospective multicenter study of 508 CM samples. METHODS: All the dermoscopic images were analyzed to identify the dermoscopic criteria found in dermoscopically difficult melanomas (DDM) and to examine the possible relation of dermoscopic diagnosis with respect to the difficulty of the dermoscopic diagnosis and the melanoma thickness. RESULTS: A significant percentage of melanomas, 89 of 508 (17.5%), were DDM. The criteria leading to a significant increased risk of DDM were presence of streaks [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.15-4.47), absence or presence of regular pigmentation (OR, 3.41; 95% CI, 1.70-6.85), absence of a blue-whitish veil (OR, 4.04; 95% CI, 2.33-6.99), absence of regression structures (OR, 4.31; 95% CI, 2.42-7.66), and the presence of hypopigmentation (OR, 2.61; 95% CI, 1.49-4.58). CONCLUSION: A significant number of melanomas defy even dermoscopic diagnosis. Only a meticulous comparative and interactive process based on an assessment of all the individual's other nevi ("ugly ducking" sign) and a knowledge about recent changes can lead to the recognition of DDM.

Adult↗
PubMedDate not supplied

Cutaneous melanoma: surveillance of patients for recurrence and new primary melanomas.

The increasing incidence and overall survival of patients diagnosed with melanoma of the skin are leading to an ever-increasing population of individuals with a personal history of melanoma. These patients are at risk for developing local, regional, or distant recurrence and are also at greater risk than the general population for developing a new primary melanoma. This article presents the rational for implementing surveillance strategies for patients with a history of melanoma.

Dermoscopy↗
PubMed2006

Empirical likelihood inference for the area under the ROC curve.

For a continuous-scale diagnostic test, the most commonly used summary index of the receiver operating characteristic curve (ROC) is the area under the curve (AUC) that measures the accuracy of the diagnostic test. In this article, we propose an empirical likelihood (EL) approach for the inference on the AUC. First we define an EL ratio for the AUC and show that its limiting distribution is a scaled chi-square distribution. We then obtain an EL-based confidence interval for the AUC using the scaled chi-square distribution. This EL inference for the AUC can be extended to stratified samples, and the resulting limiting distribution is a weighted sum of independent chi-square distributions. Additionally we conduct simulation studies to compare the relative performance of the proposed EL-based interval with the existing normal approximation-based intervals and bootstrap intervals for the AUC.

Biometry↗
PubMed2004

Non-invasive measurements of skin pigmentation in situ.

Objective in situ measurements of skin pigmentation are needed for accurate documentation of pigmentation disorders, in studies of constitutive and induced skin pigmentation, for testing of the efficacy of pro-pigmentation or de-pigmentation agents, etc. Non-invasive instrumental measurements of skin pigmentation have been used for many decades. All are based on the ability of melanin to attenuate light. However, hemoglobin in dermal capillaries also attenuates light and needs to be accounted for when pigmentation is assessed. The methods under consideration include: (a) single point measurements, in which light reflected from a defined skin area is collected and a pigment index is calculated representing the average pigmentation over the examined area, and (b) imaging methods that attempt to generate a concentration distribution map of melanin pigment for the skin area being imaged. In this article, we describe the potentials and the limitations of the different approaches to both single point and imaging methods.

Dermoscopy↗
PubMed2004

Enhancement of lesion classification using divergence, curl and curvature of skin pattern.

BACKGROUND/PURPOSE: The observation that skin pattern tends to be disrupted by malignant but not by benign skin lesions suggests that measurements of skin pattern disruption on simply captured white light optical clinical (WLC) skin images could be a useful contribution to a diagnostic feature set. Previous work which generated a flow field of skin pattern using a measurement of local line direction and variation determined by the minimum eigenvalue and its corresponding eigenvector of the local tensor matrix to measure skin pattern disruption was computationally low cost and encouraging. This paper explores the possibility of extracting new features from the first and second differentiations of this flow field to enhance classification performance. METHODS: The skin pattern was extracted from WLC skin images by high-pass filtering. The skin line direction was estimated using a local image gradient matrix to produce a flow field of skin pattern. Divergence, curl, mean and Gaussian curvatures of this flow field were computed from the first and second differentiations of this flow field. The difference of these measures combined with skin line direction across the lesion image boundary was used as a lesion classifier. RESULTS: A set of images of malignant melanoma and benign naevi were analysed as above and the scatter plot in a two-dimensional dominant feature space using principal component analysis showed excellent separation of benign and malignant lesions. A receiver operating characteristic plot enclosed an area of 0.96. CONCLUSIONS: The experimental results show that the divergence, curl, mean and Gaussian curvatures of the flow field can increase lesion classifier accuracy. Combined with skin line direction they are promising features for distinguishing malignant melanoma from benign lesions and the methods used are computationally efficient which is important if their use is to be considered in clinical practice.

Algorithms↗
PubMed2004

In vivo determination of skin surface topography using an optical 3D device.

BACKGROUND/PURPOSE: Topography of the skin surface is a mirror of the functional skin status. Therefore, its evaluation is of great interest for dermatological research. In the present study, a new optical measuring system was applied to evaluate human skin surface topography in vivo and non-invasively, in order to determine elastotic and mimic wrinkles dependent on age, body site and therapy. METHODS: The measurements were performed on the back (n=5), the flexor forearm (n=14) of volunteers in different age groups and on the face of women (n=4) participating in an anti-wrinkle study. The evaluation of the three-dimensional-profiles was performed determining skin surface parameters (mean roughness (R(a)), mean depth of roughness (R(z)), maximum roughness (R(m)) and waviness (W(t))) and applying Fourier analysis. RESULTS: Significant increases in all surface parameters were obtained on the forearms with increasing age. Differences between the surface topographies of forearm and back were only expressed by the waviness and the Fourier analysis. The treatment with botulinum Toxin A led to a diminution of mimic wrinkles as reflected by the furrow profiles. CONCLUSIONS: The results show a significant dependence of the skin surface topography on the age of the volunteer and the body site measured. Particularly the waviness, the Fourier analysis and the furrow profiles reflect such dependencies. The system used also fulfils the requirements for the testing of therapies, as was demonstrated by the reduction of mimic wrinkles after treatment with botulinum Toxin A.

Adult↗
PubMed2004

Towards objective evaluation of the skin aspect: principles and instrumentation.

BACKGROUND/AIMS: The aim of this paper is to propose an objective procedure for the evaluation of the skin aspect. This work is based on light scattering phenomena and in-vivo measurements of the skin profile and of the skin Bi-directional Reflection Distribution Function (BRDF). METHODS: We consider the basic mechanisms of light reflection and scattering by a surface to extract the key sur-face-parameters of aspect. It appears that the surface relief is determinant for the local surface orientation while the light scattering properties of the skin are responsible for the visibility of that skin relief. The first part presents the principles of skin-image formation on the retina and de-scribes the actual roles of the BRDF and of the skin relief. The second part is dedicated to experimental measurements on the skin in vivo. The 3D relief is reconstructed by a fringe projection method and numerical processing. The angular distribution of light reflected by the skin is also measured by means of a different set-up. RESULTS: The knowledge of both the skin relief obtained by 3D optical profilometry and the skin scattering behavior measured for regularly distributed set angle values, allows an objective aspect evaluation as well as a prediction of the skin images that an observer will receive. CONCLUSION: This paper presents both the principles and instrumentation elements suitable for the setting up of an objective evaluation procedure of the skin aspect.

Dermoscopy↗
PubMed2005

Colors in atypical nevi: a computer description reproducing clinical assessment.

BACKGROUND/PURPOSE: Atypical nevi (AN) share some dermoscopic features with early melanoma (MM), and computer elaboration of digital images could represent a useful support to diagnosis to assess automatically colors in AN, and to compare the data with those referring to clearly benign nevi (BN) and MMs. METHODS: An image analysis program enabling the numerical description of color areas in melanocytic lesions was used on 459 videomicroscopic images, referring to 76 AN, 288 clearly BN and 95 MMs. RESULTS: Black, white and blue-gray were more frequently found in AN than in clearly BN, but less frequently than in MMs. Color area values significantly differed between the three groups. CONCLUSION: The clinical-morphological interpretation of the numerical data, based on the mathematical description of the aspect and distribution of different color areas in different lesion types may contribute to the characterization of AN and their distinction from MMs.

Algorithms↗