Giovanni Pellacani

Dermoscopic Evaluation of Amelanotic and Hypomelanotic Melanoma

OBJECTIVE To determine the predictive dermoscopic features of amelanotic and hypomelanotic melanoma. DESIGN A total of 105 melanomas (median Breslow thickness, 0.76 mm), 170 benign melanocytic lesions, and 222 nonmelanocytic lesions lacking significant pigment (amelanotic, partially pigmented, and light colored) were imaged using glass-plate dermoscopy devices and scored for 99 dermoscopic features. Diagnostic models were derived from and tested on independent randomly selected lesions. SETTING Predominantly hospital-based clinics from 5 continents. MAIN OUTCOME MEASURES Sensitivity, specificity, and odds ratios for individual features and models for the diagnosis of melanoma and malignancy. RESULTS The most significant negative predictors of melanoma were having multiple (>3) milialike cysts (odds ratio, 0.09; 95% confidence interval, 0.01-0.64), comma vessels with a regular distribution (0.10; 0.01-0.70), comma vessels as the predominant vessel type (0.16; 0.05-0.52), symmetrical pigmentation pattern (0.18; 0.09-0.39), irregular blue-gray globules (0.20; 0.05-0.87), and multiple blue-gray globules (0.28; 0.10-0.81). The most significant positive predictors were having a blue-white veil (odds ratio,13; 95% confidence interval, 3.9-40.0), scarlike depigmentation (4.4; 2.4-8.0), multiple blue-gray dots (3.5; 1.9-6.4), irregularly shaped depigmentation (3.3; 2.0-5.3), irregular brown dots/globules (3.2; 1.8-5.6), 5 to 6 colors (3.2; 1.6-6.3), and predominant central vessels (3.1; 1.6-6.0). A simple model distinguishing melanomas from all nonmelanomas had a sensitivity of 70% and a specificity of 56% in the test set. A model distinguishing all malignant lesions from benign lesions had a sensitivity of 96% and a specificity of 37%. Conclusion Although the diagnostic accuracy of dermoscopy for melanoma lacking significant pigment is inferior to that of more pigmented lesions, features distinguishing the former from benign lesions can be visualized on dermoscopic evaluation.

In Vivo Confocal Microscopy for Diagnosis of Melanoma and Basal Cell Carcinoma Using a Two-Step Method: Analysis of 710 Consecutive Clinically Equivocal Cases

We describe two algorithms to diagnose basal cell carcinomas (BCCs) and melanomas (MMs) using in vivo reflectance confocal microscopy (RCM). A total of 710 consecutive cutaneous lesions excised to exclude malignancy (216 MMs, 266 nevi, 119 BCCs, 67 pigmented facial macules, and 42 other skin tumors) were imaged by RCM. RCM features were correlated with pathology diagnosis to develop diagnostic algorithms. The diagnostic accuracy of the BCC algorithm defined on multivariate analysis of the training set (50%) and tested on the remaining cases was 100% sensitivity, 88.5% specificity. Positive features were polarized elongated features, telangiectasia and convoluted vessels, basaloid nodules, and epidermal shadowing corresponding to horizontal clefting. Negative features were non-visible papillae, disarrangement of the epidermal layer, and cerebriform nests. Multivariate discriminant analysis on the training set (excluding the BCCs) identified seven independently significant features for MM diagnosis. The diagnostic accuracy of the MM algorithm on the test set was 87.6% sensitivity, 70.8% specificity. The four invasive MMs that were misdiagnosed by RCM were all of nevoid subtype. RCM is a highly accurate non-invasive technique for BCC diagnosis. Good diagnostic accuracy was achieved also for MM diagnosis, although rare variants of melanocytic tumors may limit the strict application of the algorithm.

The Impact of In Vivo Reflectance Confocal Microscopy on the Diagnostic Accuracy of Lentigo Maligna and Equivocal Pigmented and Nonpigmented Macules of the Face.

Limited studies have reported the in vivo reflectance confocal microscopy (RCM) features of lentigo maligna (LM). A total of 64 RCM features were scored retrospectively and blinded to diagnosis in a consecutive series of RCM sampled, clinically equivocal, macules of the face (n=81 LM, n=203 benign macules (BMs)). In addition to describing RCM diagnostic features for LM (univariate), an algorithm was developed (LM score) to distinguish LM from BM. This comprised two major features each scoring +2 points (nonedged papillae and round large pagetoid cells > 20 microm), and four minor features; three scored +1 point each (three or more atypical cells at the dermoepidermal junction in five 0.5 x 0.5 mm(2) fields, follicular localization of atypical cells, and nucleated cells within the dermal papillae), and one (negative) feature scored -1 point (a broadened honeycomb pattern). A LM score of > or = 2 resulted in a sensitivity of 85% and specificity of 76% for the diagnosis of LM (odds ratio (OR) for LM 18.6; 95% confidence interval: 9.3-37.1). The algorithm was equally effective in the diagnosis of amelanotic lesions and showed good interobserver reproducibility (87%). In a test set of 29 LMs and 44 BMs, the OR for LM was 60.7 (confidence interval: 11.9-309) (93% sensitivity, 82% specificity).

In Vivo Confocal Microscopic and Histopathologic Correlations of Dermoscopic Features in 202 Melanocytic Lesions

OBJECTIVES To identify in vivo microscopic substrates of the dermoscopic patterns of melanocytic lesions and to correlate them with histopathologic features. DESIGN Before excision, lesion areas that showed characteristic dermoscopic patterns were imaged by dermoscopy and confocal microscopy and directly correlated with histopathologic features. SETTING Departments of Dermatology of the University of Modena and Reggio Emilia and Hospital Clínico of Barcelona, between July 2006 and March 2007. Patients Patients with 202 melanocytic lesions, corresponding to 76 melanomas, 114 nevi, and 12 Spitz or Reed nevi. MAIN OUTCOME MEASURES Correlation of dermoscopic patterns in melanocytic lesions with confocal microscopic findings and conventional histopathologic findings. RESULTS Characteristic architectural and cytologic substrates were identified in vivo with the use of confocal microscopy and correlated with histopathologic features. Pigment network atypia was evidenced through confocal microscopy as a disarrangement of dermoepidermal junction architecture and cellular atypia. Pigmented globules consisted of cell clusters, corresponding to melanocytic nests identified on histopathologic analysis. Black dots correlated with intraepidermal reflective spots or with large pagetoid cells in nevi and melanoma, respectively. Blue structures usually consisted of numerous pleomorphic cells, corresponding to malignant melanocytes and inflammatory cells in melanomas, whereas plump bright cells, corresponding to melanophages on histopathologic analysis, characterized benign lesions. Within regression, a retiform distribution of collagen fibers, which sometimes intermingled with melanophages and rarely with nucleated cells, was observable. CONCLUSIONS The knowledge of the cytologic and architectural aspects of the different dermoscopic patterns, as they appear by in vivo confocal microscopy, may guide the user to the identification of specific substrates in melanocytic lesions and consequently the interpretation of the dermoscopic features.

In Vivo Reflectance Confocal Microscopy Enhances Secondary Evaluation of Melanocytic Lesions

We recently described an in vivo reflectance confocal microscopy (RCM) method and our aim was to evaluate a possible additive value of this type of analysis in the management of melanocytic lesions. In two referral centers (Sydney and Modena), lesions (203 nevi and 123 melanomas (MMs) with a median Breslow thickness of 0.54 mm) were excised on the basis of clinical suspicion (history, dermoscopy examination, and/or digital monitoring). The RCM method was also trialed on a non-biopsied population of 100 lesions, which were clinically and dermoscopically diagnosed as benign nevi. All RCM and dermoscopy diagnoses were performed blinded to the histopathological diagnosis. Firstly, in the study population, a high interobserver agreement (on a subset of 90 lesions) was seen with the RCM method, which had superior specificity (68%, 95% confidence interval (95% CI): 61.1-74.3) for the diagnosis of MM compared with dermoscopy (32%, 95% CI: 25.9-38.7), while showing no difference in sensitivity (91%, 95% CI: 84.6-95.5, RCM; 88%, 95% CI: 80.7-92.6 dermoscopy). The two techniques had a weak correlation, resulting in only 2.4% of MMs being misclassified by both techniques. Diagnosis of light-colored lesions is improved by RCM (specificity 84%, 95% CI: 66.3-94.5) compared with dermoscopy (specificity 39%, 95% CI: 23.7-56.2). Secondly, the RCM method classified 100% of the non-biopsied control nevi population as benign.

Reflectance Confocal Microscopy for In Vivo Skin Imaging

Reflectance confocal microscopy (RCM) is a novel noninvasive technique for “in vivo” examination of the skin. In a confocal microscope, near‐ infrared light from a diode laser is focused on a microscopic skin target. As this light passes between cellular structures having different refraction indexes, it is naturally reflected, and this reflected light is then captured and recomposed into a two‐dimensional gray scale image by computer software. Focusing the microscope (adjusting the focal point on the z‐axis) allows images to be obtained of different levels within the skin. Commercially available microscope systems of this type can create images with enough detail for use in histological analysis. The first investigations using these microscopes served to identify the appearance of the various cell populations living in the different layers of normal skin. Today, the main interest has become focused on the use of these microscopes as a diagnostic tool: a means of investigating benign and malignant tumors of melanocytes and keratinocytes, and, more importantly, the findings of this field of study can be used to develop a diagnostic algorithm which would be not only highly sensitive but specific as well. The aim of the paper is to provide an updated literature review and an in‐depth critique of the state‐of‐the‐art of RCM for skin cancer imaging with a critical discussion of the possibilities and limitations for clinical use.

Identification of Muir-Torre Syndrome among Patients with Sebaceous Tumors and Keratoacanthomas Role of Clinical Features, Microsatellite Instability, and Immunohistochemistry

The Muir–Torre syndrome (MTS) is an autosomal‐dominant genodermatosis characterized by the presence of sebaceous gland tumors, with or without keratoacanthomas, associated with visceral malignancies. A subset of patients with MTS is considered a variant of the hereditary nonpolyposis colorectal carcinoma, which is caused by mutations in mismatch‐repair genes. The objective of the current study was to evaluate whether a combined clinical, immunohistochemical, and biomolecular approach could be useful for the identification of Muir–Torre syndrome among patients with a diagnosis of sebaceous tumors and keratoacanthomas.

Accuracy in melanoma detection: A 10-year multicenter survey

BACKGROUND Early excision is the only strategy to reduce melanoma mortality, but unnecessary excision of benign lesions increases morbidity and healthcare costs. OBJECTIVE To assess accuracy in melanoma detection based on number-needed-to-excise (NNE) values over a 10-year period. METHODS Information was retrieved on all histopathologically confirmed cutaneous melanomas or melanocytic nevi that were excised between 1998 and 2007 at participating clinics. NNE values were calculated by dividing the total number of excised lesions by the number of melanomas. Analyses included changes in NNE over time, differences in NNE between specialized clinical settings (SCS) versus non-specialized clinical settings (NSCS), and patient factors influencing NNE. RESULTS The participating clinics contributed a total of 300,215 cases, including 17,172 melanomas and 283,043 melanocytic nevi. The overall NNE values achieved in SCS and NSCS in the 10-year period were 8.7 and 29.4, respectively. The NNE improved over time in SCS (from 12.8 to 6.8), but appeared unchanged in NSCS. Most of the effect on NNE in SCS was due to a greater number of excised melanomas. Higher NNE values were observed in patients younger than 40 years and for lesions located on the trunk. LIMITATIONS No data concerning the use of dermatoscopy and digital monitoring procedures were collected from the participating centers. CONCLUSION Over the 10-year study period, accuracy in melanoma detection improved only in specialized clinics maybe because of a larger use of new diagnostic techniques such as dermatoscopy.

In vivo assessment of melanocytic nests in nevi and melanomas by reflectance confocal microscopy.

In vivo reflectance confocal microscopy is a novel technique for the noninvasive study and diagnosis of the skin. The aim of this study was to describe and characterize the cytological and architectural aspects of cell clusters in melanocytic lesions observed by confocal microscopy, and to correlate them with routine histopathology. A total of 55 melanocytic lesions comprising 20 melanomas, 25 acquired nevi and 10 Spitz nevi were studied by means of reflectance confocal microscopy, dermoscopy and routine histopathology. Three different types of cell clusters at confocal microscopy observation (dense, sparse cell and cerebriform clusters) were identified and correlated with histopathology. Dense clusters appeared characteristic for benign lesions, although present in 13 out of 20 melanomas. Sparse cell clusters were more frequently observable in melanomas, but also sporadically present in one Spitz nevus. Moreover, cerebriform clusters were exclusively observed in five out of 20 melanomas. Confocal microscopy allowed the in vivo characterization of aspects of melanocytic nests and their exact correlation with histopathology.

Skin aging: In vivo microscopic assessment of epidermal and dermal changes by means of confocal microscopy

BACKGROUND Skin aging is thought to be a complex biological process that is traditionally classified as intrinsic and extrinsic aging. Several clinical score and instrumental devices have been applied to obtain a precise assessment of skin aging. Among them, confocal microscopy has emerged as a new technique capable of assessing cytoarchitectural changes with a nearly histopathologic resolution. OBJECTIVE We sought to determine the microscopic skin changes occurring on the face in different age groups by means of confocal microscopy. METHODS The skin of the cheek in 63 volunteers belonging to distinct age groups was analyzed by confocal microscopy. In 4 cases, routine histopathology was performed on site-matched surplus areas from routine excisions for obtaining a better comparison with confocal findings. RESULTS Young skin was characterized by regular polygonal keratinocytes and thin reticulated collagen fibers. With aging, more irregularly shaped keratinocytes and areas with unevenly distributed pigmentation and increased compactness of collagen fibers were observed. In the elderly, thinning of the epidermis, marked keratinocyte alterations, and huddles of collagen and curled fibers, corresponding to elastosis, were present. A side-by-side correlation between confocal descriptors and histopathologic aspects has been provided in a few cases. LIMITATIONS Reticular dermal changes cannot be assessed because of the limited depth laser penetration. CONCLUSIONS Confocal microscopy was successfully applied to identify in vivo skin changes occurring in aged skin at both the epidermal and dermal levels at histopathologic resolution. This offers the possibility to test cosmetic product efficacy and to identify early signs of sun damage.