Perifollicular linear projections: A dermatoscopic criterion for the diagnosis of lentigo maligna on the face.

BACKGROUND: Lentigo maligna (LM) can mimic benign, flat, pigmented lesions and can be challenging to diagnose. OBJECTIVE: To describe a new dermatoscopic feature termed "perifollicular linear projections (PLP)" as a diagnostic criterion for LM on the face. METHODS: Retrospective study on reflectance confocal microscopy and dermatoscopy images of flat facial pigmented lesions originating from 2 databases. PLP were defined as short, linear, pigmented projections emanating from hair follicles. Dermatoscopy readers were blinded to the final histopathologic diagnosis. RESULTS: From 83 consecutive LMs, 21/83 (25.3%) displayed "bulging of hair follicles" on reflectance confocal microscopy and 18 of these 21 (85.7%), displayed PLP on dermatoscopy. From a database of 2873 consecutively imaged and biopsied lesions, 252 flat-pigmented facial lesions were included. PLP was seen in 47/76 melanomas (61.8%), compared with 7/176 lesions (3.9%) with other diagnosis (P < .001). The sensitivity was 61.8% (95% CI, 49.9%-72.7%), specificity 96.0% (95% CI, 92.9%-98.4%). PLP was independently associated with LM diagnosis on multivariate analysis (OR 26.1 [95% CI, 9.6%-71.0]). LIMITATIONS: Retrospective study. CONCLUSION: PLP is a newly described dermatoscopic criterion that may add specificity and sensitivity to the early diagnosis of LM located on the face. We postulate that PLP constitutes an intermediary step in the LM progression model.

Reflectance Confocal Microscopy Criteria of Pigmented Squamous Cell Carcinoma In Situ.

Pigmented squamous cell carcinoma in situ (pSCCis) is difficult to diagnose based on clinical and dermoscopic examination. Reflectance confocal microscopy (RCM) allows noninvasive differentiation between malignant and benign pigmented skin lesions. We determined the frequency of key RCM features of pSCCis and correlated the RCM criteria with the corresponding dermoscopic and histopathologic criteria. The study included 28 lesions with biopsy-proven diagnosis of pSCCis derived from 28 patients. Clinical, dermoscopic, and RCM images of these lesions were retrospectively analyzed by 3 independent observers. Assessment for the presence of RCM criteria revealed scale or parakeratosis (20/28; 71%); irregular honeycomb pattern in the spinous-granular layer (28/28; 100%); spindle-shaped cells with dendritic branches infiltrating the epidermis (12/28; 43%); edged papillae (24/28; 86%), and dilated looped blood vessels within the papillae (18/28; 64%). Fifty-three percent of the cases displayed at least 4 RCM criteria and 96% of cases displayed at least 3 RCM criteria. We propose that the diagnosis of pSCCis could be established based on 1 major criterion-irregular honeycomb pattern-and 2 of the following minor criteria-scale or parakeratosis, spindle-shaped cells with dendritic branches infiltrating the epidermis, edged papillae, and dilated looped blood vessels within the papillae.

Accuracy of dermatoscopy for the diagnosis of nonpigmented cancers of the skin.

BACKGROUND: Nonpigmented skin cancer is common, and diagnosis with the unaided eye is error prone. OBJECTIVE: To investigate whether dermatoscopy improves the diagnostic accuracy for nonpigmented (amelanotic) cutaneous neoplasms. METHODS: We collected a sample of 2072 benign and malignant neoplastic lesions and inflammatory conditions and presented close-up images taken with and without dermatoscopy to 95 examiners with different levels of experience. RESULTS: The area under the curve was significantly higher with than without dermatoscopy (0.68 vs 0.64, P < .001). Among 51 possible diagnoses, the correct diagnosis was selected in 33.1% of cases with and 26.4% of cases without dermatoscopy (P < .001). For experts, the frequencies of correct specific diagnoses of a malignant lesion improved from 40.2% without to 51.3% with dermatoscopy. For all malignant neoplasms combined, the frequencies of appropriate management strategies increased from 78.1% without to 82.5% with dermatoscopy. LIMITATIONS: The study deviated from a real-life clinical setting and was potentially affected by verification and selection bias. CONCLUSIONS: Dermatoscopy improves the diagnosis and management of nonpigmented skin cancer and should be used as an adjunct to examination with the unaided eye.

Through the looking glass: Basics and principles of reflectance confocal microscopy.

Reflectance confocal microscopy (RCM) offers high-resolution, noninvasive skin imaging and can help avoid obtaining unnecessary biopsy specimens. It can also increase efficiency in the surgical setting by helping to delineate tumor margins. Diagnostic criteria and several RCM algorithms have been published for the differentiation of benign and malignant neoplasms. We provide an overview of the basic principles of RCM, characteristic RCM features of normal skin and cutaneous neoplasms, and the limitations and future directions of RCM.

Expert Agreement on the Presence and Spatial Localization of Melanocytic Features in Dermoscopy.

Dermoscopy aids in melanoma detection; however, agreement on dermoscopic features, including those of high clinical relevance, remains poor. In this study, we attempted to evaluate agreement among experts on exemplar images not only for the presence of melanocytic-specific features but also for spatial localization. This was a cross-sectional, multicenter, observational study. Dermoscopy images exhibiting at least 1 of 31 melanocytic-specific features were submitted by 25 world experts as exemplars. Using a web-based platform that allows for image markup of specific contrast-defined regions (superpixels), 20 expert readers annotated 248 dermoscopic images in collections of 62 images. Each collection was reviewed by five independent readers. A total of 4,507 feature observations were performed. Good-to-excellent agreement was found for 14 of 31 features (45.2%), with eight achieving excellent agreement (Gwet's AC >0.75) and seven of them being melanoma-specific features. These features were peppering/granularity (0.91), shiny white streaks (0.89), typical pigment network (0.83), blotch irregular (0.82), negative network (0.81), irregular globules (0.78), dotted vessels (0.77), and blue-whitish veil (0.76). By utilizing an exemplar dataset, a good-to-excellent agreement was found for 14 features that have previously been shown useful in discriminating nevi from melanoma. All images are public (www.isic-archive.com) and can be used for education, scientific communication, and machine learning experiments.

Seborrheic keratosis: reflectance confocal microscopy features and correlation with dermoscopy.

BACKGROUND: Differentiation between seborrheic keratosis (SK) and skin cancers may be difficult. Reflectance confocal microscopy (RCM) enables noninvasive assessment of skin neoplasms at cellular-level resolution. OBJECTIVE: We sought to describe RCM features of SK and to correlate these RCM findings with dermoscopic structures. METHODS: Clinical, dermoscopic, and RCM images of 45 consecutive SK were obtained at a private and university dermatology clinic. Fourteen SK were biopsied because of equivocal clinical or dermoscopic features. RESULTS: With RCM, all SK displayed a regular honeycomb pattern of the epidermis and densely packed, round to polymorphous, well-circumscribed dermal papillae at the dermoepidermal junction, features suggestive of a benign neoplasm. RCM features indicating the diagnosis of SK were also observed, including epidermal projections (43/45 SK; 96%) and keratin-filled invaginations (36/45 SK; 80%) at the lesion surface; corneal pseudocysts at epidermal layers (19/45 SK; 42%); and melanophages (21/45 SK; 47%) and dilated round and linear blood vessels (21/45 SK; 47%) in the papillary dermis. Of biopsied SK, 93% (13/14) displayed at least 3 characteristic RCM findings in the absence of RCM features suggestive of malignancy. LIMITATIONS: This was a limited study sample and retrospective study design. CONCLUSIONS: SK display a distinct set of RCM criteria despite their variable clinical and dermoscopic appearances.

Analysis of clinical and dermoscopic features for basal cell carcinoma neural network classification.

BACKGROUND: Basal cell carcinoma (BCC) is the most commonly diagnosed cancer in the USA. In this research, we examine four different feature categories used for diagnostic decisions, including patient personal profile (patient age, gender, etc.), general exam (lesion size and location), common dermoscopic (blue-gray ovoids, leaf-structure dirt trails, etc.), and specific dermoscopic lesion (white/pink areas, semitranslucency, etc.). Specific dermoscopic features are more restricted versions of the common dermoscopic features. METHODS: Combinations of the four feature categories are analyzed over a data set of 700 lesions, with 350 BCCs and 350 benign lesions, for lesion discrimination using neural network-based techniques, including evolving artificial neural networks (EANNs) and evolving artificial neural network ensembles. RESULTS: Experiment results based on 10-fold cross validation for training and testing the different neural network-based techniques yielded an area under the receiver operating characteristic curve as high as 0.981 when all features were combined. The common dermoscopic lesion features generally yielded higher discrimination results than other individual feature categories. CONCLUSIONS: Experimental results show that combining clinical and image information provides enhanced lesion discrimination capability over either information source separately. This research highlights the potential of data fusion as a model for the diagnostic process.

Automatic dirt trail analysis in dermoscopy images.

BACKGROUND: Basal cell carcinoma (BCC) is the most common cancer in the US. Dermatoscopes are devices used by physicians to facilitate the early detection of these cancers based on the identification of skin lesion structures often specific to BCCs. One new lesion structure, referred to as dirt trails, has the appearance of dark gray, brown or black dots and clods of varying sizes distributed in elongated clusters with indistinct borders, often appearing as curvilinear trails. METHODS: In this research, we explore a dirt trail detection and analysis algorithm for extracting, measuring, and characterizing dirt trails based on size, distribution, and color in dermoscopic skin lesion images. These dirt trails are then used to automatically discriminate BCC from benign skin lesions. RESULTS: For an experimental data set of 35 BCC images with dirt trails and 79 benign lesion images, a neural network-based classifier achieved a 0.902 are under a receiver operating characteristic curve using a leave-one-out approach. CONCLUSION: Results obtained from this study show that automatic detection of dirt trails in dermoscopic images of BCC is feasible. This is important because of the large number of these skin cancers seen every year and the challenge of discovering these earlier with instrumentation.

Sector expansion and elliptical modeling of blue-gray ovoids for basal cell carcinoma discrimination in dermoscopy images.

BACKGROUND: Blue-gray ovoids (B-GOs), a critical dermoscopic structure for basal cell carcinoma (BCC), offer an opportunity for automatic detection of BCC. Due to variation in size and color, B-GOs can be easily mistaken for similar structures in benign lesions. Analysis of these structures could afford accurate characterization and automatic recognition of B-GOs, furthering the goal of automatic BCC detection. This study utilizes a novel segmentation method to discriminate B-GOs from their benign mimics. METHODS: Contact dermoscopy images of 68 confirmed BCCs with B-GOs were obtained. Another set of 131 contact dermoscopic images of benign lesions possessing B-GO mimics provided a benign competitive set. A total of 22 B-GO features were analyzed for all structures: 21 color features and one size feature. Regarding segmentation, this study utilized a novel sector-based, non-recursive segmentation method to expand the masks applied to the B-GOs and mimicking structures. RESULTS: Logistic regression analysis determined that blue chromaticity was the best feature for discriminating true B-GOs in BCC from benign, mimicking structures. Discrimination of malignant structures was optimal when the final B-GO border was approximated by a best-fit ellipse. Using this optimal configuration, logistic regression analysis discriminated the expanded and fitted malignant structures from similar benign structures with a classification rate as high as 96.5%. CONCLUSIONS: Experimental results show that color features allow accurate expansion and localization of structures from seed areas. Modeling these structures as ellipses allows high discrimination of B-GOs in BCCs from similar structures in benign images.

Influence of time on dermoscopic diagnosis and management.

BACKGROUND/OBJECTIVES: Dermoscopy aids in clinical decision-making. However, time pressure is a common reason precluding its use. We evaluated the effect of time on lesion recognition and management decisions utilising clinical and dermoscopic images. METHOD: In all, 100 dermoscopic images were presented to 15 dermatologists with experience in dermoscopy and seven non-experts (dermatology residents). Each lesion was displayed thrice in succession. The dermoscopic image was initially presented for 1 s (t1). The same dermoscopic image was shown again without time constraints (t2) and then a final time with additional images of the clinical context (t3). Participants provided a diagnosis, their level of confidence and biopsy predilection after evaluating each image. RESULTS: For benign lesions, both groups rarely changed their diagnosis. However, an improvement in the number of correct benign diagnoses was observed when the lesion was shown in a clinical context. For malignant lesions, both groups improved when more time and clinical context was given; nevertheless, non-experts were more likely to change the diagnosis towards the correct one as more time was given and tended to perform more biopsies, in particular of benign lesions. Limitations were a small number of participants and an artificial study setting. CONCLUSION: Dermoscopy uses analytical and non-analytical reasoning approaches. We suggest that non-analytical reasoning is employed when rapid clinical decisions need to be made, especially during the evaluation of benign lesions. We conclude that dermoscopy is relatively rapid and non-time-consuming technique that adds relevant information and guides clinicians towards appropriate management decisions.

A Physician's Guide to the Use of Gene Expression Profile Ancillary Diagnostic Testing for Cutaneous Melanocytic Neoplasms.

Objectives: Some melanocytic neoplasms suspicious for melanoma require additional workup to arrive at a final diagnosis. Within the last eight years, gene expression profiling (GEP) has become an important ancillary tool to aid in the diagnosis of melanocytic neoplasms with uncertain malignant potential. As the usage of two commercially available tests (23-GEP and 35-GEP) evolves, it is important to answer key questions about optimal utilization and their impact on patient care. Methods: Recent and relevant articles answering the following questions were included in the review. First, how do dermatopathologists synthesize the available literature, the latest guidelines, and their clinical experience to determine which cases would be most likely to benefit from GEP testing? Second, how best can a dermatologist convey to their dermatopathologist that the use of GEP in the diagnostic process could provide a more clearly defined result and thereby help empower the dermatologist to provide higher-quality patient care when making specific patient management decisions for otherwise pathologically ambiguous lesions? Results: When interpreted in the context of the clinical, pathologic, and laboratory information, GEP results can facilitate the rendering of timely, accurate, and definitive diagnoses for melanocytic lesions with otherwise uncertain malignant potential to inform personalized treatment and management plans. Limitations: This was a narrative review focused on clinical use of GEP compared to other ancillary diagnostic tests performed postbiopsy. Conclusion: Open communication between dermatopathologists and dermatologists, especially regarding GEP testing, can be a vital component to achieve appropriate clinicopathologic correlation for otherwise ambiguous melanocytic lesions.

The significance of crystalline/chrysalis structures in the diagnosis of melanocytic and nonmelanocytic lesions.

BACKGROUND: Crystalline/chrysalis structures (CS) are white shiny streaks that can only be seen with polarized dermatoscopy. OBJECTIVES: We sought to estimate the prevalence and assess the clinical significance of CS in melanocytic and nonmelanocytic lesions. METHODS: This was a prospective observational study in which dermatoscopic assessment of lesions was recorded in consecutive patients examined during a 6-month period. In addition, a data set of biopsy-proven melanomas was retrospectively analyzed. RESULTS: In all, 11,225 lesions in 881 patients were prospectively examined. Retrospectively, 229 melanomas imaged with polarized dermatoscopy were analyzed. In the prospective data set, a median of 12.7 lesions (range, 1-54) were evaluated per patient. None of clinically diagnosed Clark nevi (n = 9750, 86.8%) demonstrated CS. Overall, CS were observed in 206 (1.8%) lesions, most commonly dermatofibromas and scars among nonbiopsied lesions. A total of 265 (2.4%) lesions were biopsied, including 20 melanomas and 36 nevi. Among biopsied malignant lesions, CS were most commonly observed in basal cell carcinoma (47.6%) and invasive melanomas (84.6%). Melanomas were more likely to have CS than biopsied nevi (odds ratio = 9.7, 95% confidence interval 2.7-34.1). In the retrospective data set, CS were more commonly observed among invasive melanomas (41%) compared with in situ melanomas (17%) (odds ratio = 3.4, 95% confidence interval 1.9-6.3, P < .001). The prevalence of CS correlated with increased melanoma thickness (P = .001). LIMITATIONS: Biopsied lesions represent a small percentage of the total number of lesions evaluated. CONCLUSION: Among biopsied malignant lesions, CS are most commonly observed in basal cell carcinoma and invasive melanomas and rarely seen in nevi. In melanoma, CS may reflect increased tumor thickness and progression.

Melanoma in situ in a private practice setting 2005 through 2009: location, lesion size, lack of concern.

BACKGROUND: Studies have shown that the incidence of melanoma in situ (MIS) is increasing significantly. OBJECTIVE: This study analyzes selected clinical and demographic characteristics of MIS cases observed in private dermatology practices in the United States. METHODS: This study collected 257 MIS cases from 4 private dermatology practices in the United States from January 2005 through December 2009, recording age, gender, anatomic location, lesion size, patient-reported change in lesion, and concern about lesion. Case totals for invasive melanoma during the same period were recorded. RESULTS: The data collected showed a higher incidence of MIS in sun-exposed areas of older patients, especially men. The median age of patients at the time of MIS detection was 69 years. The most common site for MIS was the head-neck region. The number of MIS cases collected exceeded the number of invasive malignant melanoma cases during the study period, with an observed ratio of 1.35:1. LIMITATIONS: For 136 patients, data were collected retrospectively for lesion size, location, gender, and age. For these patients, patient-reported change in lesion and concern about lesion were not collected. Patients often did not consent to a full body examination, therefore, it is possible that MIS lesions may have been missed in double-clothed areas. CONCLUSION: Careful attention to pigmented lesions, even lesions less than 4 mm, on sun-exposed areas, including scalp, trunk, and feet, will facilitate earlier diagnosis of MIS. As only 30.4% of male patients and 50% of female patients had concern about these lesions, it still falls to the dermatologist to discover MIS.

Dermoscopic features of basal cell carcinomas: differences in appearance under non-polarized and polarized light.

BACKGROUND: Basal cell carcinomas (BCCs) can be diagnosed using different dermoscopic modalities. OBJECTIVE: To evaluate dermoscopic features of BCCs using nonpolarized and polarized dermoscopy to highlight similarities and differences between dermoscopic modalities. MATERIALS AND METHODS: Retrospective study of 149 BCCs under nonpolarized dermoscopy (NPD), polarized contact dermoscopy (PCD), and polarized noncontact dermoscopy (PNCD). Images were evaluated for a range of dermoscopic colors, structures, and vessels. Features were compared according to histopathologic subtype. RESULTS: The most common dermoscopic structures in BCCs across all modalities included globules (50.3-51.0%), dots (49.7-50.3%), white structureless areas (63.1-74.5%), structureless gray-brown areas (24.2-24.8%), and ulcerations (28.2%). The most frequently observed vasculature included arborizing vessels (18.8-38.3%), short fine telangiectasias (SFTs) (73.8-82.6%), and vascular blush (41.6-83.2%). Structures with higher levels of agreement across modalities included pigmented structures and ulcerations. Lower levels of agreement existed between contact and noncontact modalities for certain vascular features. White shiny structures, which include shiny white lines (chrysalis and crystalline structures) (0-69.1%), shiny white areas (0-25.5%), and rosettes (0-11.4%), exhibited no agreement between NPD and polarized modalities. CONCLUSIONS: This study highlights differences in dermoscopic features of BCCs under three dermoscopic modalities. Shiny white lines (chrysalis and crystalline structures) and shiny white areas may be used as additional criteria to diagnose BCCs.

Dermoscopy of Linear Basal Cell Carcinomas, a Potential Mimicker of Linear Lesions: a Descriptive Case-series.

Introduction: Among the various widely recognized basal cell carcinoma (BCC) clinical patterns, linear basal cell carcinoma (LBCC) is an uncommon morphologic variant of BCC. Objectives: Describe the clinical and dermoscopic characteristics of LBCC. Methods: Retrospective study including LBCC cases from 5 dermatology centers in North and South America. Biopsy-proven primary BCCs, that presented with at least 3:1 length:width ratio on physical examination, irrespective of tumor subtype or location, were included. Clinical and dermoscopic analysis were performed by 2 experts in dermoscopy. Results: Eighteen cases of LBCC met our inclusion criteria and were included in the study. Median age at diagnosis was 86.0 years, 10 patients (58.8%) were males. Regarding anatomic location, 11/18 (61.1%) were located on the head and neck, 5/18 (27.7%) cases were found on the trunk, and 2 on lower extremities (11.1%). Under dermoscopy, 15/18 (83.3%) of LBCC were pigmented. All tumors displayed at least one of the BCC-specific dermoscopic criteria the most common being blue-grey globules (72.2%). Conclusions: Dermoscopy might be useful in the differentiation of LBCC from other diagnoses presenting as linear lesions such as scars, scratches/erosions, and tattoos, among others. Some of these lesions might be confused by naked eye examination alone.

Watershed segmentation of dermoscopy images using a watershed technique.

BACKGROUND/PURPOSE: Automatic lesion segmentation is an important part of computer-based image analysis of pigmented skin lesions. In this research, a watershed algorithm is developed and investigated for adequacy of skin lesion segmentation in dermoscopy images. METHODS: Hair, black border and vignette removal methods are introduced as preprocessing steps. The flooding variant of the watershed segmentation algorithm was implemented with novel features adapted to this domain. An outer bounding box, determined by a difference function derived from horizontal and vertical projection functions, is added to estimate the lesion area, and the lesion area error is reduced by a linear estimation function. As a post-processing step, a second-order B-Spline smoothing method is introduced to smooth the watershed border. RESULTS: Using the average of three sets of dermatologist-drawn borders as the ground truth, an overall error of 15.98% was obtained using the watershed technique. CONCLUSION: The implementation of the flooding variant of the watershed algorithm presented here allows satisfactory automatic segmentation of pigmented skin lesions.

Accuracy of teledermatology for nonpigmented neoplasms.

BACKGROUND: Studies of teledermatology utilizing the standard reference of histopathology are lacking. OBJECTIVE: To compare accuracy of store-and-forward teledermatology for non-pigmented neoplasms with in-person dermatology. METHODS: This study was a repeated-measures equivalence trial involving veterans with non-pigmented skin neoplasms. Each lesion was evaluated by an in-person dermatologist and a teledermatologist; both generated a primary diagnosis, up to two differential diagnoses, and management plan. The primary outcome was aggregated diagnostic accuracy (percent correct matches of any chosen diagnosis with histopathology). Secondary outcomes included management plan accuracy (percent correct matches with expert panel management plan). Additional analyses included evaluation of the incremental effect of using polarized light dermatoscopy in addition to standard macro images, and evaluating benign and malignant lesion subgroups separately. RESULTS: Most of the 728 participants were male (97.8%) and Caucasian (98.9%). The aggregated diagnostic accuracy (primary outcome) of teledermatology (macro images) was not equivalent (95% confidence interval [CI] for difference within +/-10%) and was inferior (95% CI lower bound <10%) to in-person dermatology for all lesions and the subgroups of benign and malignant lesions. However, management plan accuracy was equivalent. Teledermatology aggregated diagnostic accuracy using polarized light dermatoscopy was significantly better than for macro images alone (P = .0017). The addition of polarized light dermatoscopy showed the same pattern for malignant lesions, but not for benign lesions. Most interestingly, for malignant lesions, the addition of polarized light dermatoscopy yielded equivalent aggregated diagnostic accuracy rates. LIMITATIONS: Non-diverse study population. CONCLUSIONS: Using macro images, the diagnostic accuracy of teledermatology was inferior to in-person dermatology, but accuracy of management plans was equivalent. The addition of polarized light dermatoscopy yielded significantly better aggregated diagnostic accuracy, but management plan accuracy was not significantly improved. For the important subgroup of malignant lesions, the addition of polarized light dermatoscopy yielded equivalent diagnostic accuracy between teledermatologists and clinic dermatologists.

Accuracy of teledermatology for pigmented neoplasms.

BACKGROUND: Accurate diagnosis and management of pigmented lesions is critical because of the morbidity and mortality associated with melanoma. OBJECTIVE: We sought to compare accuracy of store-and-forward teledermatology for pigmented neoplasms with standard, in-person clinic dermatology. METHODS: We conducted a repeated measures equivalence trial involving veterans with pigmented skin neoplasms. Each lesion was evaluated by a clinic dermatologist and a teledermatologist; both generated a primary diagnosis, up to two differential diagnoses, and a management plan. The primary outcome was aggregated diagnostic accuracy (match of any chosen diagnosis with histopathology). We also compared the severity of inappropriately managed lesions and, for teledermatology, evaluated the incremental change in accuracy when polarized light dermatoscopy or contact immersion dermatoscopy images were viewed. RESULTS: We enrolled 542 patients with pigmented lesions, most were male (96%) and Caucasian (97%). The aggregated diagnostic accuracy rates for teledermatology (macro images, polarized light dermatoscopy, and contact immersion dermatoscopy) were not equivalent (95% confidence interval for difference within +/-10%) and were inferior (95% confidence interval lower bound <10%) to clinic dermatology. In general, the addition of dermatoscopic images did not significantly change teledermatology diagnostic accuracy rates. In contrast to diagnostic accuracy, rates of appropriate management plans for teledermatology were superior and/or equivalent to clinic dermatology (all image types: all lesions, and benign lesions). However, for the subgroup of malignant lesions (n = 124), the rate of appropriate management was significantly worse for teledermatology than for clinic dermatology (all image types). Up to 7 of 36 index melanomas would have been mismanaged via teledermatology. LIMITATIONS: Nondiverse study population and relatively small number of melanomas were limitations. CONCLUSIONS: In general, the diagnostic accuracy of teledermatology was inferior whereas management was equivalent to clinic dermatology. However, for the important subgroup of malignant pigmented lesions, both diagnostic and management accuracy of teledermatology was generally inferior to clinic dermatology and up to 7 of 36 index melanomas would have been mismanaged via teledermatology. Teledermatology and teledermatoscopy should be used with caution for patients with suspected malignant pigmented lesions.

Detection of basal cell carcinoma using color and histogram measures of semitranslucent areas.

BACKGROUND: Semitranslucency, defined as a smooth, jelly-like area with varied, near-skin-tone color, can indicate a diagnosis of basal cell carcinoma (BCC) with high specificity. This study sought to analyze potential areas of semitranslucency with histogram-derived texture and color measures to discriminate BCC from non-semitranslucent areas in non-BCC skin lesions. METHODS: For 210 dermoscopy images, the areas of semitranslucency in 42 BCCs and comparable areas of smoothness and color in 168 non-BCCs were selected manually. Six color measures and six texture measures were applied to the semitranslucent areas of the BCC and the comparable areas in the non-BCC images. RESULTS: Receiver operating characteristic (ROC) curve analysis showed that the texture measures alone provided greater separation of BCC from non-BCC than the color measures alone. Statistical analysis showed that the four most important measures of semitranslucency are three histogram measures: contrast, smoothness, and entropy, and one color measure: blue chromaticity. Smoothness is the single most important measure. The combined 12 measures achieved a diagnostic accuracy of 95.05% based on area under the ROC curve. CONCLUSION: Texture and color analysis measures, especially smoothness, may afford automatic detection of BCC images with semitranslucency.