Epiluminescence microscopy: A new approach to in vivo detection of sarcoptes scabiei

Background: The usual methods of scabies diagnosis include microscopic identification of the mites and their eggs and feces in skin scrapings. In many cases, the results of microscopic examination can be negative owing to the low number of parasites present in the cornified layer. Epiluminescence microscopy (ELM) is an in vivo technique that allows a detailed inspection of the skin, from the surface to the superficial papillary dermis. This is where the scabies mite lives. In this study, we evaluate the applicability and the usefulness of ELM for in vivo diagnosis of scabies. Observations: Sixty-five (93%) of 70 cases of scabies showed small, dark, triangular structures at the sites examined with ELM. A subtle linear segment seen below the base of the triangle was made visible by the presence of small air bubbles. Together, both structures re sembled a jet with contrail. On traditional microscopic examination of the scrapings, we verified that the triangular structure corresponded to the pigmented anterior section of the mite in all cases. The linear segment observed on ELM was thought to be the burrow of the mite along with its eggs and fecal pellets. The cases in which the results of a first ELM examination were negative demonstrated positive results on a second ELM examination carried out 20 days later. Conclusion: Epiluminescence microscopy is a very useful tool for in vivo diagnosis of scabies because it permits Sarcoptes scabiei detection in only a few minutes, with no discomfort to the patient and with a very low number of false-negative results

Certainty diagnosis of scabies in vivo by epiluminescence microscopy

Scabies represents a frequent and well-known skin disease provoked by infestation of Sarcoptes scabiei var hominis. It is characterized by severe generalized pruritus and by the presence of pathognomic burrows caused by the female arachnid in the epidermis. Often there are secondary symptoms such as pomphos, papules, vesicles or burrows and nodules. Currently, the diagnosis of scabies is established by optical microscopy identification of the mite, or ova in skin scraping removed from a linear or serpiginous elevation of skin in the form of a ridge 0.5-1 cm in length. Nevertheless occasionally even when numerous characteristic scabies symptoms are present, the scrape of burrow can be negative in optical microscopy. The authors showed a specific epiluminescence microscopic pathognomic picture of scabies, that can attribute a high diagnostic resolution to this technique. In respect to optical microscopy, epiluminescence permits the observation of an extended skin surface and reduces the possibility of false negative tests

Epiluminescence microscopy for port-wine staine pretreatment evaluation.

Background: Port-wine stains (PWSs) are characterized by an increased number of ectatic vessels. The treatment of choice is the use of some lasers such as pulsed dye lasers. However, some lesions are nonresponsive to laser treatment. Perhaps the vessels' depth and diameter and the thickness of the vessel wall are important factors influencing the effectiveness of the laser treatment. Methods: To investigate whether epiluminescence microscopy (ELM) could be useful in determining the effectiveness of laser treatment of PWSs, we studied a group of patients with PWSs using both ELM and histological analysis. Results: A correlation existed between a gray-whitish veil seen by ELM and the vessel depth judged by histology: when the veil was absent, the vessels were always found to be located only in the upper third of the dermis. Conclusion: We think that the gray-whitish veil is a distinctive dermoscopic feature that is able to differentiate between superficial vessels (absence of veil) and deeper vessels (presence of veil)

Clinical and dermatoscopic criteria for the preoperative evaluation of cutaneous melanoma thickness

Background: Melanoma thickness measured according to the Breslow method is used to determine surgical margin and in patient selection for sentinel node biopsy. Previous studies did not confirm the reliability of melanoma palpability for clinical prediction of tumor thickness. Recently we reported the usefulness of epiluminescence microscopy (dermatoscopy) for in vivo detection of the phases of melanoma progression, as well as tumor depth. Objective: Our purpose was to determine whether the combination of clinical and dermatoscopic criteria could increase the accuracy in preoperative evaluation of melanoma thickness with respect to the clinical elevation and dermatoscopic assessments considered separately. Methods: In a blind retrospective study, 122 cutaneous melanomas were studied to evaluate the presence of several clinical and dermatoscopic criteria and their relation with the histologic thickness. An algorithm of combined criteria was constructed and statistically assessed. Results: Combinations of palpability, diameter of more than 15 mm, pigment network, gray-blue areas, and atypical vascular pattern allowed correct prediction of thickness in 89% of melanomas when categorized in two groups of less than 0.76 mm and more than 0.75 mm thickness, compared with 75% using palpability, and 80% using dermatoscopic criteria. Lower values were obtained in the further subdivision of melanomas into groups of 0.76 to 1.5 mm and more than 1.5 mm thickness. Conclusion: The combination of clinical and dermatoscopic criteria is a more precise guide for the preoperative evaluation of melanoma thickness than either is alone. However, further studies are needed to verify its applicability in establishing the surgical approach to cutaneous melanoma

Epiluminescence microscopy: Criteria of cutaneous melanoma progression

Background: Cutaneous melanoma develops through a series of evolutionary steps (intraepidermal, radial, and vertical growth phases) that are traceable in specific histologic features. Epiluminescence microscopy (ELM) is an in vivo technique that enables the visualization of morphologic structures in pigmented lesions correlated with specific histologic architectural characteristics. Many ELM criteria associated with cutaneous melanoma have been described, but their correlation with tumor progression has not yet been established. Objective: In this preliminary study our purpose was to explore the possibility of recognizing ELM criteria that allow the in vivo detection of the various phases of melanoma progression as well as tumor depth. Methods: Seventy-two cutaneous melanomas (41 'thin' melanomas [TnM], 0.75 mm thickness) were investigated with ELM for the presence of nine standard ELM criteria; their significance was determined by calculating the chi-square test of independence. Results: A significant association is found between the presence of pigment network and TaM and between the presence of gray-blue areas, vascular pattern, and TkM. Moreover, pigment network plus radial streaming is the most significant association of ELM criteria in TnM, whereas gray-blue areas plus vascular pattern is the greatest in TkM. Conclusion: This study shows a good correlation between certain ELM criteria and the histologic architecture of cutaneous melanoma for a preoperative evaluation of the tumor thickness. Further investigation is needed for verifying on a larger number of cases our pilot estimates of sensitivity and specificity of ELM criteria in thin and thick melanomas

A statistical analysis of the characteristics of pigmented skin lesions using epiluminescence microscopy

Due to the fact that not all pigmented skin lesions (PSL) can be diagnosed solely by their clinical appearance, additional criteria are required to optimize the clinical diagnosis of atypical nevus and melanoma. Epiluminescence microscopy is a non-invasive in vivo examination that often helps to improved the accuracy of clinical diagnosis of such lesions. Years of experience have indicated some differential epiluminescent patterns for benign and malignant PSI, but there is some controversy about certain borderline lesions for which histological examination is always necessary. In our study we performed a statistical analysis of data concerning 183 PSI, to determine characteristics significantly associated with these lesions allowing identification of epiluminescent criteria suggestive of atypical nevus and malignant melanoma. Using he chi-quadro test and stepwise regression logistic model, we identified the following epiluminescent pattern as a risk factor for atypical nevus and malignant melanoma: irregular pigment network, presence of capillaries, irregular and abrupt ending of overall pigmentation, irregular brown globules and irregular shape and size of black dots

Dermoscopy of uncommon variants of dermatofibrosarcoma protuberans

Darier-Ferrand dermatofibrosarcoma protuberans (DFSP) is a locally aggressive fibrohistiocytic tumour with a low metastatic potential.(1) Because of its rarity, slow progression and lack of early clinical clues, the diagnosis of DFSP is often delayed. Classical DFSP clinically appeared like an indurated, irregularly-shaped plaques exhibiting flesh to reddish-brown colour. Some lesions also showed thin teleangectasia on the surface (Fig. 1, a). This article is protected by copyright. All rights reserved

Epiluminescence microscopy for the diagnosis of doubtful melanocytic skin lesions: Comparison of the ABCD rule of dermatoscopy and a new 7-point checklist based on pattern analysis

Objective: To compare the reliability of a new 7-point checklist based on simplified epiluminescence microscopy (ELM) pattern analysis with the ABCD rule of dermatoscopy and standard pattern analysis for the diagnosis of clinically doubtful melanocytic skin lesions. Design: In a blind study, ELM images of 342 histologically proven melanocytic skin lesions were evaluated for the presence of 7 standard criteria that we called the 'ELM 7-point checklist.' For each lesion, 'overall' and 'ABCD scored' diagnoses were recorded. From a training set of 57 melanomas and 139 atypical non-melanomas, odds ratios were calculated to create a simple diagnostic model based on identification of major and minor criteria for the '7-point scored' diagnosis. A test set of 60 melanomas and 86 atypical non-melanomas was used for model validation and was then presented to 2 less experienced ELM observers, who recorded the ABCD and 7-point scored diagnoses. Settings: University medical centers. Patients: A sample of patients with excised melanocytic lesions. Main Outcome Measures: Sensitivity, specificity, and accuracy of the models for diagnosing melanoma. Results: From the total combined sets, the 7-point checklist gave a sensitivity of 95% and a specificity of 75% compared with 85% sensitivity and 66% specificity using the ABCD rule and 91% sensitivity and 90% specificity using standard pattern analysis (overall ELM diagnosis). Compared with the ABCD rule, the 7-point method allowed less experienced observers to obtain higher diagnostic accuracy values. Conclusions: The ELM 7-point checklist provides a simplification of standard pattern analysis because of the low number of features to identify and the scoring diagnostic system. As with the ABCD rule, it can be easily learned and easily applied and has proven to be reliable in diagnosing melanoma