Non-melanocytic Skin Lesions Research Articles

Melanocytic Aggregation in the Skin: Diagnostic Clues from Lentigines to Melanoma

Pigmented skin lesions are among the most common skin lesions. Among them, melanocytic proliferations are morphologically diverse and their behavior may be difficult to discern with certainty. Researchers must be able to distinguish melanocytic from nonmelanocytic pigmented skin lesions and, in particular, benign from malignant lesions. The majority of these lesions can be diagnosed with ease; however, a minority of cases is difficult and have potential for error. The authors have systematically analyzed the clinical and dermoscopic features of melanocytic skin lesions, so as to increase in vivo diagnostic accuracy.

The impact of dermoscopic–pathological correlates in the diagnosis and management of pigmented skin tumors

Dermoscopy is an optical, in vivo technique that has recently gained, at least in many European countries, popularity as an aid to the clinical diagnosis of pigmented, benign and malignant, melanocytic and nonmelanocytic skin lesions. The improvement in diagnostic accuracy of pigmented skin lesions compared with clinical examination is based on the uncovering of specific, submacroscopic, morphological key structures located in the epidermis down to the upper dermis that are usually not visible to the naked eye.

Sensitivity and specificity of confocal laser‐scanning microscopy for in vivo diagnosis of malignant skin tumors

Melanoma and nonmelanoma skin cancer are the most frequent malignant tumors by far among whites. Currently, early diagnosis is the most efficient method for preventing a fatal outcome. In vivo confocal laser-scanning microscopy (CLSM) is a recently developed potential diagnostic tool. One hundred seventeen melanocytic skin lesions and 45 nonmelanocytic skin lesions (90 benign nevi, 27 malignant melanomas, 15 basal cell carcinomas, and 30 seborrheic keratoses) were sampled consecutively and were examined using proprietary CLSM equipment. Stored images were rated by 4 independent observers. Differentiation between melanoma and all other lesions based solely on CLSM examination was achieved with a positive predictive value of 94.22%. Malignant lesions (melanoma and basal cell carcinoma) as a group were diagnosed with a positive predictive value of 96.34%. Assessment of distinct CLSM features showed a strong interobserver correlation (kappa >0.80 for 11 of 13 criteria). Classification and regression tree analysis yielded a 3-step algorithm based on only 3 criteria, facilitating a correct classification in 96.30% of melanomas, 98.89% of benign nevi, and 100% of basal cell carcinomas and seborrheic keratoses. In vivo CLSM examination appeared to be a promising method for the noninvasive assessment of melanoma and nonmelanoma skin tumors.

Modified Dermoscopic Algorithm for the Differentiation between Melanocytic and Nonmelanocytic Skin Tumors

The use of dermoscopy (dermatoscopy, epiluminescence microscopy, surface microscopy) improves the clinical diagnostic accuracy of skin tumors by applying different algorithms or scores. The first step in the dermoscopic evaluation is the differentiation between melanocytic and nonmelanocytic skin tumors. To evaluate the diagnostic accuracy of the established dermoscopic algorithm (EDA) and the modified dermoscopic algorithm (MDA) for melanocytic versus nonmelanocytic skin tumors. Two hundred forty-nine patients with melanocytic and nonmelanocytic skin lesions were included. Dermoscopic images of the tumors were taken with 10-fold magnification, followed by surgery and histopathology at the departments of Dermatology at the universities of Tuebingen, in Germany, and Naples, in Italy. Each lesion was classified using the EDA and MDA. In the MDA, accessory nipples and dermatofibromas were considered in particular. With the EDA, 225 of 249 (90.4%) skin tumors were correctly classified in one of the six groups. With the MDA, 237 of 249 (95.2%) were correctly classified. Improvement was achieved in 12 (4.8%) better classified skin tumors. In both algorithms, no melanoma was classified as a nonmalignant melanocytic tumor. All melanomas were classified in the group of melanocytic tumors and one melanoma was classified in the group of basal cell carcinomas. Both dermoscopic algorithms for the differentiation between melanocytic and nonmelanocytic skin tumors were simple and effective when applied step by step. The MDA is an improvement on the EDA with the classification of accessory nipples and dermatofibromas.

Dermoscopy: alternative melanocytic algorithms—the ABCD rule of dermatoscopy, menzies scoring method, and 7-point checklist

In the year 2000, the Second Consensus Meeting on Dermoscopy was held over the Internet. Experts from around the world were asked to evaluate melanocytic, nonmelanocytic, benign, and malignant skin lesions using pattern analysis, the ABCD rule of dermatoscopy, Menzies scoring method, and the 7-point checklist. One hundred twenty-eight digital dermoscopic images were randomly subdivided into a training set of 20 images in which the unifying concepts of pattern analysis, the ABCD rule of dermatoscopy, Menzies scoring method, and the 7-point check list were presented. Those melanocytic algorithms were then used to evaluate another 108 cases. The results of the Second Consensus Meeting were presented at the First World Congress of Dermoscopy held in Rome, Italy, March 2001 and in an atlas that outlined the results and illustrated all of the cases.1,2 One of the main conclusions from the Second Consensus Meeting was that the four melanocytic algorithms studied were all valid ways to evaluate pigmented skin lesions with dermoscopy. This article will present the unifying concepts of the ABCD rule of dermatoscopy, Menzies scoring method, and the 7-point checklist. Other less-well-known and studied dermoscopic algorithms will not be presented.3–5

Dermoscopy of pigmented skin lesions – a valuable tool for early

The clinical use of dermoscopy has uncovered a new and fascinating morphological dimension of pigmented skin lesions. Dermoscopy is a non-invasive diagnostic technique that links clinical dermatology and dermatopathology by enabling the visualisation of morphological features not seen by the naked eye. Close examination of pigmented skin lesions in this way increases the effectiveness of clinical diagnostic tools by providing new morphological criteria for distinguishing melanoma from other melanocytic and non-melanocytic pigmented skin lesions. In the past, dermoscopy has been known by various names, including skin surface microscopy, epiluminescence microscopy, incident light microscopy, dermatoscopy, and videodermatoscopy. However, the term 'dermoscopy', first used by Friedman and colleagues in 1991, is the most widely used.

S100 expression in cutaneous scars: a potential diagnostic pitfall in the diagnosis of desmoplastic melanoma.

The histological distinction of desmoplastic melanoma from cutaneous scar tissue, particularly in the context of re-excision specimens or possible recurrence, may be very difficult. Immunostaining for S100 protein is often used to discriminate although there are little data on S100 expression in scar tissue. The aim of this study was to assess whether S100-positive cells are present in dermal scars and, if so, their extent, distribution and nature. Twenty-two re-excision specimens of previously biopsied nonmelanocytic skin lesions were reviewed. Formalin-fixed paraffin-embedded sections containing dermal scars were stained by a standard ABC immunoperoxidase technique for S100 protein, CD1a and neurofilaments. The distribution and morphology of positive cells within the dermal scar tissue were documented. Cells expressing S100 protein were identified within the scars of 21 of the 22 cases. The number of S100-positive cells varied between cases but in four specimens was substantial. They displayed a variety of morphological appearances but the majority were spindle-shaped. A few showed mild cytological atypia. It is suggested that the majority represent Schwann cells with a minority of Langerhans cells and cells of uncertain lineage. S100-positive cells, including spindle cells showing mild atypia, are found in cutaneous scars. S100 staining of re-excision specimens or putative recurrences of desmoplastic melanoma should be interpreted with caution.

Minimal deviation and/or naevoid melanoma: is recognition worthwhile? A clinicopathological study of nine cases.

One to two per cent of primary cutaneous melanomas share clinical features with benign melanocytic and non-melanocytic skin lesions, and even at histology recognition of their malignant nature is problematic, mainly due to the lack of an intraepithelial component, their nodular aspect and the monotonous cell population throughout the lesion. These tumours were termed minimal deviation melanomas (MDMs) by Reed et al. and later naevoid melanomas by Schmoeckel et al. The name MDM suggests the concept of a more favourable outcome for these melanomas that do not (yet) show the typical features of fully evolved lesions able to metastasize, although naevoid melanomas seem to behave like 'common' melanomas. In a retrospective analysis of nine cases of MDM collected from our database and followed for a median duration of 112 months, we faced similar clinical and histological pitfalls and observed local recurrence following marginal resection. Wide excision, even of local recurrence, and therapeutic node dissection could nevertheless provide survival comparable at least to that predicted by mathematical models for patients who initially had optimal treatment.