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A systematic review of publications addressing change in vitamin D status (25-hydroxyvitamin D (25OHD)) after exposure to UV radiation identified 2001 independent peer-reviewed publications. Of these, 21 used artificial sources of UV radiation, met all inclusion criteria and were quality assured; 13 publications used solar radiation and met sufficient inclusion criteria to be retained as supporting evidence; 1 further included publication used both solar and artificial sources. The review consistently identified that low dose, sub-erythemal doses are more effective for vitamin D synthesis than doses close to a minimum erythema dose; increasing skin area exposed increases the amount of vitamin D synthesised although not necessarily in a linear manner; constant dosing leads to a dose-dependent plateau in 25OHD, and dose–response is greatest at the start of a dosing regime; there is a large interpersonal variation in response to UV exposure. Fourteen of the studies using artificial sources of radiation were used to determine a dose–response relationship for change in 25OHD on whole-body exposure to repeated sub-erythemal doses of UV radiation, taking the form Δ25OHD (nmol/L) = A ln(standard vitamin D dose) + B. This helps quantify our understanding of UV as a source of vitamin D and enables exposure regimes for safe synthesis of vitamin D to be assessed. Specific studies of people with pigmented skin (Fitzpatrick skin types 5 and 6) were rare, and this dose–response relationship is only applicable to white-skinned individuals as skin type is a determinant of response to UV radiation. Findings provide information for vitamin D guidance updates.

Usually the lower part of melanocyte nevi is at a depth of not more than 1–2 mm or more, which is typical for congenital nevi, as well as for large pigmented tumors that protrude significantly above the skin surface and have a pronounced intradermal part. Incomplete removal of pigmented nevi occurs during their superficial removal with insufficient capture of healthy tissues. When excision of pigmented nevi by acute method means in the vast majority of cases of incomplete removal can be avoided, and primarily because the suturing of the edges of the postoperative wound requires much deeper excision of tissues. Рurpose – to increase the effectiveness of surgical treatment of pigmented skin tumors in children by using a mathematical model. Materials and methods. The study was conducted on the basis of the oncohematology department of Vinnytsia Regional Children’s Clinical Hospital, a mathematical model for calculating the parameters of operational access was conducted on the Microsoft Excel platform. Results. Using the proposed mathematical model, the following parameters of the operating material were calculated: the area of the resection edges of the operating material; the area of the base of the operating material; the total area of morphological examination of the surface of the surgical material; determining the difference in the volume of surgical material to be histologically examined by different methods of its collection. In all cases, the tumor for three-dimensional histological examination was excised in the form of an ellipse with a safety zone (healthy tissue around the tumor). The surgical direction of the incision was formed with an inclination to the surface of the skin towards the tumor with the formation of an acute angle with it, while the upper part of the dermis was cut less than its lower part. This approach to the formation of the profile of the surgical wound improves the conditions for further reconstructive wound defect closure. Conclusions. Comparative mathematical calculation according to the proposed spatial geometric model of the biopsy in the form of a truncated elliptical cone convincingly shows an increase in the useful volume of surgical material in the planned histological examination compared with the cylindrical elliptical configuration of the biopsy due to involvement in the field of microscopic structures «residual structures» (processes) corresponding to melanocyte nevi, under the guise of which the development of the initial stages of melanoma may occur. The research was carried out in accordance with the principles of the Helsinki declaration. The study protocol was approved by the Local Ethics Committee of these Institutes. The informed consent of the patient was obtained for conducting the studies. The authors declare no conflicts of interests. Key words: children, melanocyte nevi, operative accesses.

Cultured epidermal autografts (CEA) are surgical therapeutic alternatives for patients with stable vitiligo resistant to conventional medical treatments. In the present study, we assessed color matching before and at 12 months after CEA treatment. Eleven patients with 16 vitiligo lesions were included in this prospective study. The recipient sites were prepared by CO2 laser superficial ablation and subjected to CEA application. We clinically evaluated and categorized the color matching of the repigmented skin as well as the percentage of repigmentation. We also obtained three color values (L*a*b*) for the vitiligo lesions and surrounding normally pigmented skin. We then calculated the color differences between the two regions and compared them before and at 12 months after treatment. The mean percentage of repigmentation was 63.3% at 12 months. Six of the 16 lesions were categorized as “same as” and had color difference values of ≤5 at 12 months after treatment. Clinical evaluation of the color matching coincided well with the calculated color difference values. CEA application after CO2 laser superficial ablation was useful for treating vitiligo assessed by the percentage of repigmentation and color matching. Quantification of color differences may be a useful parameter for evaluating color matching in vitiligo.

Pigmented skin lesions are common spots or growths on the skin that originate from melanocyte cells. Skin cancer occurs as a result of the uncontrolled division of melanocyte cells. Skin cancer is common worldwide and its incidence has been increasing. Timely and accurate diagnosis of skin cancer is important in reducing deaths. Skin cancer cases are diagnosed by expert dermatologists, but the number of experts is insufficient for the population. Dermoscopy is one of the most commonly used methods for imaging skin lesions. Sometimes misdiagnosis can occur in the interpretation of dermoscopic images by human experts. Computer-aided systems help to make accurate and objective decisions in the diagnosis of skin lesions. Convolutional neural network(CNN) is a deep learning technique commonly used in the field of computer vision and is also widely used in medical image analysis In this study, a CNN model was proposed to classify seven different skin lesions in the HAM10000 dataset. The model provided a classification accuracy of 91.51%. The performance of the model was compared with similar studies in the literature and it was found that it showed higher success than most studies. The model was connected to a web application and evaluated in two phases by seven expert dermatologists. In the first phase, it was concluded that the model could diagnose skin lesions with 90.28% accuracy in practice. In the second phase, the model corrected the experts' misdiagnoses by 11.14%.

Background and objectives In this study, the threshold fluences for disrupting the melanosomes for pigmented skin lesion treatment were determined using a 755-nm picosecond laser for clinical use. Based on the melanosome disruption thresholds, incident fluences corresponding to the target lesion depths were evaluated in silico for different laser spot sizes. Study design/materials and methods Melanosome samples were isolated from porcine eyes as alternative samples for human cutaneous melanosomes. The isolated melanosomes were exposed to 755-nm picosecond laser pulses to measure the mean particle sizes by dynamic light scattering and confirm their disruption by scanning electron microscopy. The threshold fluences were statistically determined from the relationships between the irradiated fluences and the mean particle sizes. Incident fluences of picosecond laser pulses for the disruption of melanosomes located at different depths in skin tissue were calculated through a light transport simulation using the obtained thresholds. Results The threshold fluences of 550- and 750-picosecond laser pulses were determined to be 2.19 and 2.49 J/cm2 , respectively. The numerical simulation indicated that appropriate incident fluences of picosecond laser pulses differ depending on the depth distribution of the melanosomes in the skin tissue, and large spot sizes are desirable for disrupting the melanosomes more deeply located within the skin tissue. Conclusion The threshold fluences of picosecond laser pulses for melanosome disruption were determined. The incident fluence analysis based on the thresholds for melanosome disruption provides valuable information for the selection of irradiation endpoints for picosecond laser treatment of pigmented skin lesions. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Purpose: A clinical hurdle for dermatopathology is the accurate diagnosis of melanocytic neoplasms. While histopathologic assessment is frequently sufficient, high rates of diagnostic discordance are reported. The development and validation of a 35-gene expression profile (35-GEP) test that accurately differentiates benign and malignant pigmented lesions is described. Methods: Lesion samples were reviewed by at least three independent dermatopathologists and included in the study if 2/3 or 3/3 diagnoses were concordant. Diagnostic utility of 76 genes was assessed with quantitative RT-PCR; neural network modeling and cross-validation were utilized for diagnostic gene selection using 200 benign nevi and 216 melanomas for training. To reflect the complex biology of melanocytic neoplasia, the 35-GEP test was developed to include an intermediate-risk zone. Results: Validation of the 35-GEP was performed in an independent set of 273 benign and 230 malignant lesions. The test demonstrated 99.1% sensitivity, 94.3% specificity, 93.6% positive predictive value and 99.2% negative predictive value. 96.4% of cases received a differential result and 3.6% had intermediate-risk. Conclusions: The 35-GEP test was developed to refine diagnoses of melanocytic neoplasms by providing clinicians with an objective tool. A test with these accuracy metrics could alleviate uncertainty in difficult-to-diagnose lesions leading to decreased unnecessary procedures while appropriately identifying at-risk patients.

Introduction: The number-needed-to-biopsy (NNB) metric measures the efficiency of a clinician’s ability to accurately diagnose and recommend pigmented skin lesions (PSLs) for biopsy for suspected melanomas. Electrical impedance spectroscopy (EIS) is a non-invasive technique that measures differences in resistance between healthy and cancerous skin cells, intended as an aid to enhance diagnostic accuracy.Methods: Dermatology clinicians of three distinct groups (residents, physician assistants/nurse practitioners, and practicing dermatologists) were evaluated on their ability to accurately recommend suspect PSLs for biopsy before and after the integration of EIS data.Results: All three groups had a reduction in NNB after the inclusion of EIS. Instances of missed biopsies for malignant melanoma were significantly reduced with simultaneous significant reductions in unnecessary biopsies for benign lesions. There was a material improvement of biopsy selection for PSLs having clinically challenging features. EIS also greatly improved the diagnostic acumen of clinicians whose assessments were less accurate than their peers prior to EIS incorporation.Conclusions: The integration of EIS technology into the PSL biopsy decision was demonstrated to be effective in significantly enhancing clinician NNB and more accurate PSL biopsy selection.

BACKGROUND The melanin fluorescence of skin lesions is measurable with two-photon excitation, a process termed dermatofluoroscopy, which has shown a shift from the green spectra in benign melanocytic lesions to the red spectra in melanoma. This study addressed the question as to which kind of pigmented lesions can be correctly diagnosed as melanin-bearing malignant tumors. METHODS 476 pigmented lesions including 101 cutaneous melanomas were analyzed with dermatofluoroscopy, measuring the melanin fluorescence in a grid-like fashion with a separation of measurement points of 0.2 mm. The results of the dermatofluoroscopy are presented as a diagnostic score with a cut-off score of ≥ 28 for the diagnosis of melanin-bearing malignant tumors, and were compared to the gold standard of histopathology. RESULTS A highly significant difference (p

BACKGROUND Pigmentary problems are one of the most frequent causes for dermatologic consultation. Skin colour is highly individual and the variations are controlled by numerous genes. Correct diagnosis of skin disorders including pigmented lesions depends on histopathologic examination of skin biopsies and clinicopathologic correlation. METHODS This is a hospital based observational study done for a period of 2 years from July 2017 to June 2019 with a sample size of 88 cases in the Department of Pathology, Andhra Medical College, Visakhapatnam. Specimens were formalin fixed and the tissue was adequately processed for histopathological examination. The sections were stained routinely with haematoxylin and eosin and examined under light microscopy. RESULTS Out of the 88 cases, 30 cases were inflammatory lesions which include 14 cases of classic lichen planus, 6 cases of lichen planus hypertrophicus, 9 cases of lichen planus pigmentosus and 1 case of lichenoid keratosis. 35 cases were benign lesions comprising 21 cases of benign melanocytic nevi and 14 cases of seborrheic keratosis. 23 malignant lesions include 16 cases of basal cell carcinoma and 7 cases of melanoma. Most common affected age group was 51-60 yrs. Most common site involved in malignant lesions was face (34.33%). There is slight female preponderance. Most common pigmented lesion under malignant category was basal cell carcinoma about 16 cases. 75 cases (85%) were correlated clinically. CONCLUSIONS Classic Lichen planus is the most common lesion seen under inflammatory category. The diagnosis of seborrheic keratosis is mainly based on the histopathological examination in order to differentiate from other pigmented skin lesions, hence a careful histopathological diagnosis is important.

Telemedicine may be described as a modern technology supporting health care at a distance. Dermatology, as a visually-dependent specialty, is particularly suited for this kind of the health care model. This has been proven in a number of recent studies, which emphasized feasibility and reliability of teledermatology. Many patients in the world still do not have access to appropriate dermatological care, while skin cancers morbidity is on an upward trend. Technological development has enabled clinicians to care for diverse patient populations in need of skin expertise without increasing their overhead costs. Teledermatology has been used for various purposes: health care workers can use this technology to provide clinical services to patients, to monitor patient health, to consult with other health care providers and to provide patients with access to educational resources. It seems that teledermatology might be the answer to numerous issues concerning diagnosing, screening and managing cancers as well as pigmented skin lesions.

Melanoma is a serious condition affecting people around the world. Therefore, automatic diagnostics of pigmented skin lesions is an area of high interest. Possible approach to diagnostics is based on detection of dermoscopic attributes. In this study we consider developing an end-to-end solution for the task of dermoscopic attributes detection based on the data of ISIC (International Skin Imaging Collaboration) competition dataset. We investigate the possibility to improve performance using labeling of different modality in the form of segmentation masks. We propose to use the segmentation task as an auxiliary task and allow sharing knowledge between these two tasks by training a neural network of Y-Net architecture, which allows sharing of the weights between segmentation and classification branches. Additionally, we propose several modes of combining training of Y-Net based on segmentation and classification labels. The best of proposed methods has reached F1 score of 0.527 comparing to plain classification’s 0.502.

Phototherapy in skin of color requires special consideration. Pigmented skin is an efficient ultraviolet filter. Hence, higher doses of ultraviolet radiation are generally more effective and well tolerated in skin of color. An objective and practical system has not yet been established to determine optimal phototherapy dosing in skin of color. The authors recommend obtaining a detailed history of each individual patient's response to sun exposure before prescribing a phototherapy dosing regimen. In addition, providers should consider the role of socioeconomic factors and their impact on phototherapy-related outcomes, including barriers to access and compliance.

The article proposes a neural network classification system for pigmented skin neoplasms with a preliminary processing stage to remove hair from the images. The main difference of the proposed system is the use of the stage of preliminary image processing to identify the location of the hair and their further removal. This stage allows you to prepare dermatoscopic images for further analysis in order to carry out automated classification and diagnosis of pigmented skin lesions. Modeling was carried out using the MatLAB R2020b software package on clinical dermatoscopic images from the international open archive ISIC Melanoma Project. The proposed system made it possible to increase the recognition accuracy of pigmented skin lesion images in 10 diagnostically important categories up to 80.81%. The use of the proposed system for the recognition and classification of images of dermatoscopic pigmented lesions by specialists will make it possible to increase the diagnostic efficiency in comparison with methods of visual diagnosis, and will also allow starting treatment at an earlier stage of the disease, which directly affects the survival and recovery rates for patients.

We congratulate Drs Iwuala & Taylor for their review 'Structural and functional differences in skin of colour'. In support of this work, biochemical studies conducted on human volar forearms rather than faces were referenced. Here we share aspects of our own research studying largely facial skin of women living in South Africa that we feel are relevant to the discussion on the differences in the structure and function of the stratum corneum (SC) among differently pigmented skin types.

To assess Irish dermatologists' confidence with dermatology in patients with skin of colour (SOC), an online survey was distributed to all members of the Irish Association of Dermatology (IAD) by email. Half (50%) of respondents were 'not confident' or 'not at all confident' in diagnosing skin conditions and one-third (33.9%) were 'not confident' or 'not at all confident' in managing skin conditions in patients with SOC. Irish dermatologists have low confidence with skin pathology in SOC, and specific training could reduce this disparity.

The aim of the study was to assess differences in the influence of high-intensity laser therapy (HILT) on the skin surface temperature and vein diameter of the lateral fetlock joint region in a group of racehorses with pigmented and non-pigmented skin in the treatment area. Twenty Thoroughbreds were divided into two equal groups: pigmented and non-pigmented skin groups. Each horse received the same HILT treatment. Just before and immediately after HILT, thermographic examination was performed to measure the skin surface temperature and ultrasonographic examination assessed the lateral digital palmar vein diameter. After HILT, the pigmented skin surface temperature increased, while the non-pigmented skin surface temperature decreased, and the difference between both groups was significant (p &lt, 0.001). The vein diameter increased after HILT in horses with pigmented and non-pigmented skin, but the difference between both groups was not significant (p = 0.14). In conclusion, melanin content in the epidermis plays an important role in light energy absorption and photothermal effects. The vein diameter changes after HILT application indicated that the increase in vessel diameter may partly depend on photothermal mechanisms occurring in irradiated tissue. Further research is necessary to describe the physiological and clinical effects of HILT performed on pigmented and non-pigmented skin.

In artificially reared flatfish, especially the Japanese flounder Paralichthys olivaceus, pigmented skin (hypermelanosis) frequently appears on the fish’s blind side after normal metamorphosis. As no practical prevention method has yet been proposed, we examined the effectiveness of a loose net placed inside the rearing tank that covers the bottom and walls like a pouch. When juveniles (standard length [SL] 6 cm) were transferred to the net-lined tank (mesh size 4 mm) before the first appearance of hypermelanosis, the pigmented area after 2 months covered about 0.5% of the blind side; this is about 1/40th of the area covered by pigment in fish reared in an ordinary tank (20%). Although the initial appearance of pigmentation in the axilla area (the area covered by the pectoral fin) was not suppressed, utilization of a larger mesh size (12 mm) decreased the expansion of pigmentation in this area. Juveniles reared in the net-lined tank were about 5–15% smaller (SL) than those reared in the ordinary tank, but their body depth:SL ratio was closer to that of wild-caught juveniles. From the results of this study, we propose that net-lined rearing tanks with larger-sized mesh are a practical method of preventing hypermelanosis in Japanese flounder aquaculture systems.

Background: Pigmented skin lesions refers to melanocytic as well as nonmelanocytic lesions. Pigmentation is not just a cosmetic deformity but can also reflect underlying benign pathology as nevi or malignant lesions as melanoma. With this study we intend to evaluate the spectrum of pigmented skin lesions and to correlate the clinical diagnosis with the histological diagnosis. Materials and Methods: This is a hospital based cross sectional descriptive study where clinicohistopathological evaluation of 46 cases of pigmented skin lesions were analyzed on paraffin embedded tissue sections for a duration of 1 year at the Department of Pathology, B. P. Koirala Institute of Health Sciences. Results: Out of the 46 cases evaluated there were 32 cases of melanocytic lesions comprising of benign melanocytic nevi (n=27), malignant melanoma (n=5) and 14 cases of nonmelanocytic lesions including basal cell carcinoma and seborrhoeic keratosis (5 cases each). Angiokeratoma (n=1), sebaceous hyperplasia (n=1), trichoepitheloma (n=1) and venous haemangioma (n=1). The age range was from 8-83 years with slight female predominance (52.2%) and the most common site involved was head and neck (58.7%). 76.1% of the patients belonged to the Terai region. Clinicohistopathological correlation showed positive correlation in 26 cases (56.5%) and negative correlation in 20 cases (43.5%). Conclusions: Pigmented skin lesions are common presenting problem, while majority are benign a small minority can be malignant. So, clinically pigmented skin lesions should be submitted for pathological examination in order not to miss a small percentage of malignant tumors and to differentiate melanocytic lesions from its nonmelanocytic mimickers.

Summary Differentiation of pagetoid cutaneous neoplasms can be very challenging on hematoxylin and eosin-stained sections. We report a singular case of pigmented pagetoid Bowen’s disease showing transitional features between extramammary Paget’s disease and in situ squamous cell carcinoma.

Background Pigmented skin lesions in childhood and adolescence can be diagnostically challenging. It is important for general practitioners to be aware of the spectrum of benign, atypical and malignant pigmented lesions occurring in these patient groups and of features that should raise concern. Objective The aims of this article are to assist recognition of high-risk skin lesions encountered in childhood and adolescence and to provide an understanding of the features and management of suspected melanoma in this population. Discussion In children and adolescents, there exist a variety of congenital and acquired naevi and other pigmented skin lesions that can be diagnostically problematic. Additionally, conventional detection criteria for melanoma seen in adults are often not present in children and adolescents, making diagnosis more difficult. Melanoma, if diagnosed in these populations, should be treated at a specialist centre whenever possible.

Vitiligo, which manifests as varying sizes and shapes of well-circumscribed amelanotic macules or patches amid normally pigmented skin, has a quite common onset during childhood. The most common treatments of childhood vitiligo are topical corticosteroids, topical calcineurin inhibitors and targeted phototherapy. Adequate sun protection and cosmetic camouflage may also be of benefit. It is also important to identify individuals in need of psychological support, as childhood vitiligo can negatively impact psychosocial factors and health-related quality of life.

Summary The dragonfish is a voracious predator of the deep sea with an arsenal of tools to hunt prey and remain concealed. In contrast to its dark pigmented skin, the dragonfish is equipped with transparent teeth. Here, we establish the structure, composition, and mechanical properties of the transparent teeth for the first time. We find the enamel-like layer to consist of nanocrystalline hydroxyapatite domains (∼20 nm grain size) embedded in an amorphous matrix, whereas in the dentin layer the nanocrystalline hydroxyapatite coats nanoscale collagen fibrils forming nanorods. This nanoscale structure is responsible for the much-reduced Rayleigh light scattering, which is further ensured by the sufficiently thin walls. Here, we suggest that the nanostructured design of the transparent dragonfish teeth enables predatory success as it makes its wide-open mouth armed with saber-like teeth effectively disappear, showing no contrast to the surrounding blackness of the fish nor the background darkness of the deep sea.

The purpose of this study was to evaluate the ability of alternate light source illumination to enhance bruises in pigmented skin. Previous work was limited to simulating bruises in non-pigmented (Caucasoid type) skin by injecting blood into pigskin. In this study, it was investigated if adding a layer of melanin to the surface of the skin would simulate pigmented skin. The study included evaluating the use of a filter that transmitted infrared light (wavelength greater than 720 nm) in place of the recommended visible light filters for the alternate light sources. The results obtained using pigskin with a layer of melanin were almost the same as results using the naturally pigmented goat ear. This indicated adding a layer of melanin could be used as a model for pigmented skin in this simulation of fresh bruising. Comparing the pigskin without melanin with pigskin with melanin revealed that the optimal light source to enhance the appearance of bruising, simulated by injection of blood, changed from violet to blue-green. Using the infrared transmitting filter resulted in greater enhancement than using the alternate light sources with their recommended visible light filter. The advantage of using the infrared transmitting filter was greater with the pigskin coated with melanin and the naturally pigmented goat ears than in the non-pigmented pigskin, however, the results remain to be validated using real bruises in naturally pigmented human skin.

The Scientific community has been developing computer-aided detection systems (CADs) for automatic diagnosis of pigmented skin lesions (PSLs) for nearly 30 years. Several works have addressed this issue and obtained encouraging results, however, there has not been much focus on the pre-processing step, determining the relevance of the features considered and how they may be important indicators of a lesion’s malignancy. To differentiate between nevus and melanoma skin lesions, the development of CAD system is a challenging task due to the use of inaccurate image processing techniques. In this paper, a new classification system is developed for PSLs known as DermoDeep through a fusion of multiple visual features and deep-neural-network approach. A new aggregation of visual features along with descriptors are extracted in a perceptual-oriented color space. Moreover, a new five-layer architecture based DermoDeep system is proposed. This DermoDeep system applied on 2800 region-of-interest (ROI) PSLs including 1400 nevus and 1400 malignant lesions. The classification accuracy of DermoDeep system is compared with the state-of-the-art methods and evaluated by the sensitivity (SE), specificity (SP) and area under the receiver operating characteristics (AUC) curve. The difference between AUC of DermoDeep is statistically significant compared to other techniques with AUC: 0.96 (p

A clinically oriented Computer-Aided Diagnostic (CAD) system is of prime importance for the diagnosis of melanoma, since the deadly disease is associated with high morbidity and mortality. Unfortunately, the development of CAD tools is hampered by several issues, such as (i) smooth boundaries between the lesion and the surrounding skin, (ii) subtlety of features between the melanoma and non-melanoma skin lesions, and (iii) lack of reproducibility of CAD systems due to complexity. The proposed system aims to address the aforementioned issues. First, the lesion regions are localized by incorporating chroma based deformable models. Second, the lesion patterns are analyzed to detect various dermoscopic criteria. Further, a robust ensemble architecture is developed using dynamic classifier selection techniques to detect malignancy. Quantitative analysis is performed on two diverse datasets (ISBI and PH2) achieving an accuracy of 88% and 97%, sensitivity of 95% and 97% and specificity of 82% and 100% for ISBI and PH2 datasets respectively.

A method for differentiation of pigmented skin lesions is proposed that is based on digital processing of optical images. The optical images are detected using a digital camera and a standard for its color and spatial calibration. The method involves segmentation and automatic recognition of neoplasms on the basis of five parameters: diameter, area, color, shape, and border sharpness. The analysis reveals clinical features of the lesion, required for diagnosis, and allows for calculating the probability of its malignant transformation. The method proposed was tested on 360 digital images of in vivo skin pigment lesions, including ordinary dysplastic nevi and melanoma. The sensitivity and specificity of the method proved to be 97 and 95%, respectively.

Pigmented Bowen's disease (pBD) is a subtype of Bowen's disease, which presents clinically as a well-circumscribed, hyperpigmented plaque. Its clinical manifestations are not fully characterized, and differential diagnoses include various pigmented skin lesions. Dermoscopy could be useful for the diagnosis, although nothing has been reported on the dermoscopic features of clonal-type pBD. We herein report a first case of clonal-type pBD on the sole and its dermoscopic features. Dermoscopy showed brown to blue-gray dots/globules and focally anastomosing lines on the non-weight-bearing area, while the weight-bearing area had a brown to blue-gray fibrillar-like pattern. To investigate the relationship between dermoscopy and histopathology, we focused on the melanin distribution in the horny layer of the epidermis, and used vertical dermoscopy observation. We investigated the relationship between dermoscopy and pathology by melanin depth estimation using a color lightness value.

Introduction The incidence and mortality of melanoma are rising rapidly. Despite ongoing research and the introduction of new therapeutic methods, advanced melanoma is still considered incurable. Early detection and surgical excision of the tumor increases patients' survival. Since the diagnostic protocol includes surgical excision of all suspicious lesions, it is burdened with a high rate of unnecessary excisions that cause unwanted scarring. This is why the development of accurate diagnostic techniques is crucial. The most common diagnostic tool in early diagnosis of cutaneous melanoma is dermoscopy, though there are emerging new techniques, such as reflectance confocal microscopy and optical coherence tomography. Aim To evaluate diagnostic accuracy of reflectance confocal microscopy as a secondary examination in melanocytic lesions previously diagnosed as melanomas by means of dermoscopy. Material and methods Forty-six melanocytic lesions presenting dermoscopic features of cutaneous malignant melanoma were examined by means of reflectance confocal microscopy. Results The RCM evaluation showed sensitivity at the level of 100% and specificity at 62%. Conclusions It can be estimated that double evaluation of melanocytic lesions by dermoscopy and reflectance confocal microscopy may allow up to 62% of unnecessary excisions to be avoided.

Purpose: The aim of this work was to describe the epidemiological, clinical and therapeutic features of pigmented skin acne in Benin. Methods: This was a prospective, cross-sectional and analytical study conducted in the dermatology departments of the Borgou-Alibori Departmental Teaching Hospital and the National Teaching Hospital Hubert Koutoukou Maga from January 2017 to December 2018, which has included black-skinned patients who were diagnosed with acne and gave their free and informed consent. The ECLA score was used for clinical evaluation of the severity of the acne. Results: We collected 129 patients including 35 men and 94 women. The median age of the patient was 24.6 years ± 8.5 years. The median age of onset was 17.9 years ± 7.6 years. The main triggering of worsening factors was inadequate self-medication (53.5%), excoriation (48.1%), certain foods (34.9%) and lightening cosmetic (32.5%). Most patients had inflammatory (51.9%) or comedonal (31.8%) acne associated with post-inflammatory hyperpigmentations (70.5%) and excoriated lesions (31%). In the majority of cases, acne was moderate in women (52.1%) and severe in men (62.8%) with p = 9 × 10-3. The lesions were electively seated in the face (95.3%), mainly on the forehead and cheeks. Active cosmetics (76.7%), retinoids (58.9%), oral antibiotics (55.8%), and benzoyl peroxide (48.9%) were the most commonly used therapeutic classes. Conclusion: The majority of young and adult women consulted for predominant inflammatory acne on the forehead and cheeks, moderate in woman and severe in men in Benin. The therapeutic arsenal consisted mainly of active cosmetics, retinoids, antibiotics and benzoyl peroxide.