Parallel Ridge Pattern Research Articles

Validation of a dermatoscopy-based algorithm for the diagnosis of acral melanoma.

Diagnosis of acral melanocytic lesions can be challenging. The BRAAFF checklist was introduced as a tool to help differentiate between acral nevi and melanoma but has not been validated. We asked raters with varying expertise in dermatoscopy to diagnose dermatoscopic images of 533 acral nevi and 144 melanomas via an online platform with and without use of the BRAAFF checklist. From the ratings we calculated sensitivity, specificity, and interrater agreement. Additionally, a new simplified version of the checklist was also tested. We collected 6880 ratings from 175 readers. The BRAAFF checklist achieved a sensitivity of 92.5% and a specificity of 65.0%, which was similar to diagnosis from pattern recognition (sensitivity 90.0%, specificity: 72.1%). Interrater agreement for the BRAAFF criteria ranged from fair to moderate, with lowest agreement for parallel ridge and fibrillar pattern (alpha=0.31) and highest for asymmetry of colors and structures (alpha=0.46). Agreement and diagnostic accuracy were higher for more experienced readers. A simplified version with only two criteria achieved similar sensitivity (95.0%) and lower specificity (60.0%) as the original BRAAFF checklist. Conclusion: The BRAAFF checklist is a useful tool for the diagnosis of melanocytic acral lesions with acceptable sensitivity and reasonable specificity but is not superior to pattern recognition. A simplified version of the checklist could be easier to use with equal sensitivity while exhibiting a modest reduction in specificity.

A Narrative Review of the Evolution of Diagnostic Techniques and Treatment Strategies for Acral Lentiginous Melanoma.

Acral melanoma (AM) is a subtype of cutaneous melanoma located on the palms, soles, and nails. The pathogenesis of AM involves mechanical stimulation and characteristic tumor-promoting mutations, such as those in the KIT proto-oncogene. Dermoscopy is useful for diagnosing AM, which is characterized by parallel ridge patterns and irregular diffuse pigmentation. Although histopathological confirmation is the gold standard for diagnosing AM, lesions showing minimal histopathological changes should be considered early-stage AM if they clinically resemble it. Recently, immunohistochemical staining of preferentially expressed antigen in melanoma has been recognized as a useful method to distinguish benign from malignant melanocytic tumors. Research reveals that AM is associated with an immunosuppressive microenvironment characterized by increased numbers of M2 macrophages and regulatory T cells, alongside a decreased number of tumor-infiltrating lymphocytes. Mohs micrographic surgery or digit-sparing wide local excision has been explored to improve quality of life and replace wide local excision or proximal amputation. AM has a worse prognosis than other subtypes, even in the early stages, indicating its inherent aggressiveness.

An innovative process chain for the production of antibiofouling polymer parts using ultrafast laser texturing

Polymers are versatile materials widely used in various industries, with significant applications in biomedicine where biofouling on polymer surfaces presents major health and economic challenges. Biofouling, initiated by bacterial adhesion, can be mitigated by modifying surface properties through laser micro- and nano-texturing, an approach that offers advantages over chemical treatments. This study introduces an economical mass production process for textured polymeric components using injection molding to replicate hierarchical textures. Testing revealed that all textured samples significantly reduced bacterial adhesion compared to untextured surfaces across different designs and bacteria types after 24 h of culture. The study examined factors like wettability, nanoscale roughness, and pattern dimensions to explain these outcomes, comparing them with existing studies. Despite all textured samples showing decreased wettability and roughness, these factors alone did not ensure reduced bacterial adhesion. The most effective anti-adhesive performance was observed in surfaces with parallel ridge patterns, which segmented the surface into isolated areas that limited bacterial interaction and hindered micro-colony formation, highlighting the importance of specific surface patterning in combating biofouling.

Pattern Analysis of Benign and Malignant Atypical Melanocytic Skin Lesions of Palms and Soles: Variations of Dermoscopic Features According to Anatomic Site and Personal Experience.

Background: The differential diagnosis of atypical melanocytic skin lesions localized on palms and soles represents a diagnostic challenge: indeed, this spectrum encompasses atypical nevi (AN) and early-stage melanomas (EN) displaying overlapping clinical and dermoscopic features. This often generates unnecessary excisions or delayed diagnosis. Investigations to date were mostly carried out in specific populations, focusing either on acrolentiginous melanomas or morphologically typical acquired nevi. Aims: To investigate the dermoscopic features of atypical melanocytic palmoplantar skin lesions (aMPPLs) as evaluated by variously skilled dermatologists and assess their concordance; to investigate the variations in dermoscopic appearance according to precise location on palms and soles; to detect the features with the strongest association with malignancy/benignity in each specific site. Methods: A dataset of 471 aMPPLs-excised in the suspect of malignancy-was collected from 10 European Centers, including a standardized dermoscopic picture (17×) and lesion/patient metadata. An anatomical classification into 17 subareas was considered, along with an anatomo-functional classification considering pressure/friction, (4 macroareas). A total of 156 participants (95 with less than 5 years of experience in dermoscopy and 61 with ≥than 5 years) from 17 countries performed a blinded tele-dermoscopic pattern analysis over 20 cases through a specifically realized web platform. Results: A total of 37,440 dermoscopic evaluations were obtained over 94 (20%) EM and 377 (80%) AN. The areas with the highest density of EM compared to AN were the heel (40.3% EM/aMPPLs) of the sole and the "fingers area" (33%EM/aMPPLs) of the palm, both characterized by intense/chronic traumatism/friction. Globally, the recognition rates of 12 dermoscopic patterns were non statistically different between 95 dermatology residents and 61 specialists: aMPPLs in the plantar arch appeared to be the most "difficult" to diagnose, the parallel ridge pattern was poorly recognized and irregular/regular fibrillar patterns often misinterpreted. Regarding the aMPPL of the "heel area", the parallel furrow pattern (p = 0.014) and lattice-like pattern (p = 0.001) significantly discriminated benign cases, while asymmetry of colors (p = 0.002) and regression structures (p = 0.025) malignant ones. In aMPPLs of the "plantar arch", the lattice-like pattern (p = 0.012) was significant for benignity and asymmetry of structures, asymmetry of colors, regression structures, or blue-white veil for malignancy. In palmar lesions, no data were significant in the discrimination between malignant and benign aMPPLs. Conclusions: This study highlights that (i) the pattern analysis of aMPPLs is challenging for both experienced and novice dermoscopists; (ii) the histological distribution varies according to the anatomo-functional classification; and (iii) different dermoscopic patterns are able to discriminate malignant from benign aMPPLs within specific plantar and palmar areas.

Race-Specific and Skin of Color Dermatoscopic Characteristics of Skin Cancer: A Literature Review.

Individuals with melanin-rich skin account for the majority of the world's population. However, literature data regarding dermatoscopic characteristics of skin cancer in skin of color (SoC) are scarce. The dermatoscopic characteristics of cutaneous tumors might differ among skin types due to heterogeneity in composition and pigmentation. To summarize literature data on the dermatoscopic findings of skin neoplasms, according to the skin color and race. The literature search was performed using PubMed database up to December 30, 2022 and was conducted with the use of terms referring to dermatoscopy, race (Caucasians, Hispanics, Asians, and Black/African) and skin cancer types (BCC, SCC, keratoacanthoma, Bowen's disease and melanoma). In total, 30 race-specific records were included. 9 SoC records for BCCs (2 BCC studies in Hispanics, 1 BCC study in Black individuals and 6 BCC studies in Asians ), 9 SoC records for SCCs ( 1 SCC study in Hispanics, 1 SCC study in Black individuals and 7 SCCs in Asian population) and 8 SoC records for melanoma (2 melanoma studies in Hispanics, 1 melanoma study in Blacks and 5 melanoma studies in Asians) were compared with 4 records that involved only Caucasian population, according to their participant section as well as with studies on dermatoscopy characteristics without focusing on race origins and phototype of the patient. In Hispanics and in both fair and dark-skinned Asians, BCCs were more often pigmented or at least with pigmented structures on dermoscopy. Squamous cell carcinoma (SCC) and keratoacanthoma were the least studied in SoC patients. Bowen's disease in SoC patients can be pigmented in a higher frequency compared to Caucasians, with glomerular vessels and a squamous surface being the most common dermatoscopic findings. The most frequent pattern of melanomas in SoC individuals were the parallel ridge pattern in palmoplantar region. Based on a review of studies including Caucasians, Hispanics, Asians and Blacks /Africans, SoC patients present with more frequent and unique dermatoscopy features of skin cancers.

Pagetoid Dyskeratosis of the Hand With Parallel Ridge Pattern on Dermoscopy and Expression of Bcl-10 by Immunohistochemistry.

*Department of Dermatology, Oregon Health and Science Center, Portland Oregon †Department of Dermatology, Valley Medical Center, Renton Washington; and ‡Department of Pathology, Virginia Mason Medical Center, Seattle WA. Correspondence: Steven M. Ruhoy, MD, Department of Pathology, Virginia Mason Medical Center, Seattle WA (e-mail: [email protected]). The authors declare no conflicts of interest.

Acral Melanocytic Neoplasms: A Comprehensive Review of Acral Nevus and Acral Melanoma in Asian Perspective.

Acral melanocytic neoplasms, including acral melanocytic nevus and acral melanoma, are common melanocytic lesions in Asian populations. Both lesions occur on the volar surface of the hands and feet, and on nail units. Acral melanocytic nevi occur on the arch area of the sole, whereas acral melanomas frequently occur on weight-bearing areas of the sole, and on the fingernails. Therefore, the development of acral melanoma may be associated with chronic pressure, physical stress, or trauma. Dermoscopy is a useful adjunctive diagnostic tool for differential diagnosis. Acral melanocytic nevus is characterized by a parallel furrow pattern, whereas acral melanoma has a parallel ridge pattern. Genetic alterations are also different between the two types of lesion. BRAF and NRAS mutations are common in acral melanocytic nevus, whereas acral melanoma shows lower rates of KIT, NF1, BRAF, and NRAS mutations and remarkable copy number variations in genes such as CCND1, CDK4, hTERT, PAK1, and GAB2. Sentinel lymph node biopsy is important for staging and prognosis. Contemporary treatments for melanoma include targeted therapy for mutations and immunotherapy, such as anti-PD1 inhibitors.

Features of Skin Cancer in Black Individuals: A Single-Institution Retrospective Cohort Study.

IntroductionMinimal knowledge exists regarding skin cancers in Black individuals, which may adversely affect patient care.ObjectivesTo describe clinical features and risk factors of skin cancers in Black individuals.MethodsRetrospective study of Black individuals diagnosed with skin cancer between January 2000 and January 2020 at our institution.Results38,589 patients were diagnosed with skin cancer, of which 165 were Black individuals. One-hundred-thirteen of these Black individuals were diagnosed with melanoma, 35 with squamous cell carcinoma (SCC), and 17 with basal cell carcinoma (BCC). Most melanomas (80.0%, n = 90) were of the acral subtype; 75% (6 of 8 cases with dermoscopic images) displayed a parallel ridge pattern (PRP). The surrounding uninvolved background skin was visible in 7 cases, all demonstrating a PRP. This disappeared adjacent to most of the melanoma lesions (n = 4, 57.1%). creating a peripheral hypopigmented “halo”. The nonmelanoma skin cancers were pigmented and had similar dermoscopic features as reported in predominantly White populations. Most SCCs (n = 5, 71.4%) had a hypopigmented “halo” and most BCCs (n = 10, 55.6%) had an accentuated reticular network adjacent to the lesions.ConclusionsSkin cancers are pigmented in Black individuals. In both acral melanomas and SCCs, we noted a peripheral rim of hypopigmentation between the lesions and the surrounding uninvolved background skin, while BCCs had accentuation of the background pigmentation adjacent to the lesions. Most acral melanomas displayed a PRP, which was also seen in surrounding uninvolved background skin.

Acral hyperpigmented macule suspicious of malignant melanoma

Dermoscopy is a noninvasive useful tool to differentiate malignant melanoma from other benign or malignant skin lesions. One of the recent advances in dermoscopy is the significance of parallel ridge pattern, which has 99% specificity in detecting malignant melanoma on the acral volar skin. Here, we report a case of acral hyperpigmented macule suspicious of malignant melanoma.

Hutchinson Sign: Biopsy May Assist in Diagnosis of Subungual Melanoma in Situ.

Early and accurate diagnosis of subungual melanoma (SUM) through histopathologic examination is critical, but lack of clinical suspicion leads to delays in diagnosis. Hutchinson sign (HS) can be one of the important clinical indicators for diagnosing SUM. To evaluate the diagnostic value of small biopsies of HS for detecting SUM in situ. We retrospectively evaluated 12 patients who were diagnosed as SUM in situ and underwent punch biopsy at HS areas. Clinical features, dermoscopic findings, and histopathologic findings in HS regions were analyzed. In most cases, HS was seen in hyponychium (11/12, 91.7%) with 1 case found in proximal nail fold, and 1 case in both the hyponychium and proximal nail fold. Dermoscopic features of HS showed irregular diffuse pigmentation (12/12, 100%) and parallel ridge pattern (7/12, 58.3%). Histopathologically, all cases showed irregularly scattered atypical melanocytes with hyperchromatic nuclei. Two cases showed subtle changes in melanocytes with little nuclear atypia, but additional section specimen showed more definitive findings of SUM in situ. We present a supplementary biopsy technique for diagnosing SUM. Biopsy of HS may help in the diagnosis of SUM.

Dermatoscopy of melanoma according to type, anatomic site and stage.

The indisputable contribution of dermatoscopy in early diagnosis of melanoma is widely recognized. In the last quinquennium, new data concerning specific melanoma subtypes have come to light. The dermatoscopic morphology of superficial spreading melanoma (SSM) has been extensively investigated in the literature. Atypical network, irregular dots, irregular globules, irregular streaks and irregular blotch correspond to histopathologic alterations at the level of the junction, blue-white veil and atypical vessels suggest intradermal growth, whereas regression structures, negative network and white shiny streaks might reflect junctional or dermal alterations. The list of melanoma specific criteria has been recently updated to include features that typify early melanoma, such as irregular hyperpigmented areas and prominent skin markings and features seen in melanoma on sun damaged skin such as angulated lines. Nodular melanoma lacks most of the aforementioned criteria and is typified by the coexistence of blue and black color, atypical vessels and pink color. Lentigo maligna dermatoscopic criteria mainly develop at the outline of the follicular openings. However, at an early stage these features might be very subtle and the diagnosis should be based on the exclusion of benign tumors (inverse approach). Acral lentiginous melanoma is typified by a parallel ridge pattern, but also SSM criteria should be taken into consideration. The diagnosis of subungual melanoma is based on the assessment of the color and characteristics of the pigmented nail band. For the diagnosis of mucosal melanoma, the assessment of colors is more informative than the assessment of structures and the detection of blue, white or gray should raise the suspicion of melanoma. White shiny streaks and regression structures are the most common features of desmoplastic melanoma. The diagnosis of nevoid melanoma might be highly challenging and require information on the lesion's history. Melanoma on small- and medium-sized congenital nevi is typified by an eccentric location of the suspicious area, negative network and gray angulated lines. Recent advances in knowledge on the dermatoscopic characteristics of peculiar subtypes of the tumor significantly enrich the diagnostic armamentarium of clinicians. The challenge of the forthcoming years is to better characterize biologically aggressive melanomas and to optimize the screening strategies so as to identify them.

Three-dimensional histological explanation of the dermoscopy patterns in acral melanocytic lesions.

Dermoscopic images of pigmented lesions have distinct features on the sole where skin ridges and furrows exist. Pigmentation of benign nevus usually locates on the skin furrow, while the malignant melanoma is pigmented on the skin ridge. Correspondence between dermoscopy and pathology in the pigmented lesions on soles have been studied based on conventional vertical pathological images. However, for the full understanding of the correspondence, observation of horizontal histological images would be required, because the epidermis constructs unique horizontal structures, namely crista profunda limitans, crista profunda intermedia, and transverse ridge. In this study, we analyzed basic dermoscopic images of the representative acral melanocytic lesions (nevus, lentigo, and malignant melanoma) by horizonal histological images. We created serial horizontal pathological images by digital reconstruction of a hundred of serial vertical images. We could show that parallel furrow pattern is created by the pigmentation of crista profunda limitans, parallel ridge pattern by the pigmentation of both of crista profunda limitans and crista profunda intermediate, and lattice-like pattern by the pigmentation of transverse ridge. Our results would be useful for the intuitive histological understanding of dermoscopy.

Dermatoscopy of melanoma according to type, anatomic site and stage: a 2020 update

The indisputable contribution of dermatoscopy in early diagnosis of melanoma is widely recognized. In the last quinquennium, new data concerning specific melanoma subtypes have come to light. The dermatoscopic morphology of superficial spreading melanoma (SSM) has been extensively investigated in the literature. Atypical network, irregular dots, irregular globules, irregular streaks and irregular blotch correspond to histopathologic alterations at the level of the junction, blue-white veil and atypical vessels suggest intradermal growth, whereas regression structures, negative network and white shiny streaks might reflect junctional or dermal alterations. The list of melanoma specific criteria has been recently updated to include features that typify early melanoma, such as irregular hyperpigmented areas and prominent skin markings and features seen in melanoma on sun damaged skin such as angulated lines. Nodular melanoma lacks most of the aforementioned criteria and is typified by the coexistence of blue and black color, atypical vessels and pink color. Lentigo maligna dermatoscopic criteria mainly develop at the outline of the follicular openings. However, at an early stage these features might be very subtle and the diagnosis should be based on the exclusion of benign tumors (inverse approach). Acral lentiginous melanoma is typified by a parallel ridge pattern, but also SSM criteria should be taken into consideration. The diagnosis of subungual melanoma is based on the assessment of the color and characteristics of the pigmented nail band. For the diagnosis of mucosal melanoma, the assessment of colors is more informative than the assessment of structures and the detection of blue, white or gray should raise the suspicion of melanoma. White shiny streaks and regression structures are the most common features of desmoplastic melanoma. The diagnosis of nevoid melanoma might be highly challenging and require information on the lesion's history. Melanoma on small- and medium-sized congenital nevi is typified by an eccentric location of the suspicious area, negative network and gray angulated lines. Recent advances in knowledge on the dermatoscopic characteristics of peculiar subtypes of the tumor significantly enrich the diagnostic armamentarium of clinicians. The challenge of the forthcoming years is to better characterize biologically aggressive melanomas and to optimize the screening strategies so as to identify them.

Diagnostic application of cyclin D1 fluorescent in situ hybridization for histologically undetermined early lesions of acral melanoma in situ: A case series

Histologically undetermined early acral melanoma in situ (HUAMIS) is rare but a diagnostic challenge, being clinically and dermoscopically MIS (late onset, a large size (>7 mm), parallel ridges pattern) but microscopically without recognizable cytological atypia. Cyclin D1 (CCND1) gene amplification is a genetic aberration occurring in the early radial growth phase of AMs and could thus help determine malignancy for this disease.We determine the value of CCND1 amplification by FISH as a diagnostic marker for HUAMIS. CCND1 amplification was examined in paraffin-embedded skin biopsies and excisions using a dual-probes fluorescence in situ hybridization (FISH) (11q13 and CEP11). One FISH-negative case 6 was additionally examined by Mypath Melanoma (qRT-PCR). Seventeen cases (12 dysplastic nevi, 3 AMIS, and 2 invasive AM) were served as negative controls for FISH.All six patients (4 females and 2 males) were Hispanic. Pigment lesions were on the left plantar foot (4), right third finger palm (1), and right thumb subungual (1). All cases showed similar clinical and dermoscopical characteristics, including late onset (50 to 74 years old), long duration (from 2 to 15 years), large-sized pigments (from 16 to 40 mm), and a parallel ridge pattern. Junctional melanocytes with no or minimal atypia from five cases showed CCND1 amplifications. Four of 5 cases were received 1st or/and 2nd wide excisions, which demonstrated foci of histologically overt MIS. One FISH-negative case 6 demonstrated “likely malignancy” scores (>2) by Mypath Melanoma (qRT-PCR). None of negative controls showed the amplification.We propose here a simple CCND1 FISH is a practical diagnostic test to determine the malignancy of the very early progression phase of AM preceding histopathologically defined MIS. Cases presented here could be an indolent subtype of AMIS characterized by carrying a long latent radial growth phase without vertical growth, mimicking lentigo maligna.

Acral lentiginous melanoma in situ: dermoscopic features and management strategy

Diagnosis of acral lentiginous melanoma in situ (ALMIS) is challenging. However, data regarding ALMIS are limited in the literature. The aim of this study was to investigate the clinical and dermoscopic features of ALMIS on palmoplantar surfaces. Patients with ALMIS and available dermoscopic images were retrospectively reviewed at our institution between January 2013 and February 2020. Clinical and dermoscopic features were analysed and compared between small (< 15 mm) and large (≥ 15 mm) ALMIS. Twenty-one patients with ALMIS were included in this study. Mean patient age was 58.5 (range 39–76) years; most lesions were located on the sole (90.5%). The mean maximal diameter was 19.9 ± 13.7 mm (mean ± standard deviation). Statistical analysis of dermoscopic features revealed that parallel ridge patterns (54.5% vs. 100%, P = 0.035), irregular diffuse pigmentation (27.3% vs. 100%, P = 0.001) and grey colour (18.2% vs. 90%, P = 0.002) were significantly less frequent in small lesions than in large lesions. We have also illustrated two unique cases of small ALMIS; their evolution and follow-up dermoscopic examination are provided. In conclusion, this study described detailed dermoscopic findings of ALMIS. Based on the present study and a review of the literature, we proposed a dermoscopic algorithm for the diagnosis of ALMIS.

Acquired agminated melanocytic nevus in the acral area is a potential mimicker of acral lentiginous melanoma: A three-case series report and published work review.

Agminated nevus refers to a clustered group of melanocytic nevi confined to a localized area of the body. It rarely involves acral skin, but recognition of acquired agminated nevus (AAN) in the acral area is clinically important because it may mimic acral lentiginous melanoma (ALM). However, acral AAN has only been described in a few case reports and its clinical characteristics remain unclear. We report three additional cases of acral AAN to further analyze the differential points between ALM. Clinical images, including those of dermoscopy, of three cases of acral AAN were reviewed. The lesions were located on the sole or lateral border of the foot. All acral AAN were flat and large in size (>20mm in greatest dimension), and associated with asymmetry and irregular border. However, no parallel ridge pattern suggesting ALM was observed on dermoscopy. In two patients, the lesions on the sole were totally resected; microscopic evaluation of these two lesions confirmed junctional nests of banal melanocytes. AAN lesions on the sole with chronic mechanical pressure are slightly larger and more diffuse; thus, they may be more likely to be overdiagnosed as malignancy upon inspection than those in the non-acral area. Understanding the concept of the disease and careful dermoscopic evaluation leads to an accurate diagnosis.

Comparison of dermoscopic features between congenital and acquired acral melanocytic nevi in Korean patients.

The dermoscopic patterns of acral melanocytic nevi (AMNs) are crucial in differentiating them from acral melanoma. Several studies have reported the dermoscopic patterns of acquired acral melanocytic nevi (AAMNs). However, few have investigated the dermoscopic patterns of congenital acral melanocytic nevi (CAMNs). To compare the clinical and dermoscopic features of CAMNs and AAMNs. The present study included 43 patients with CAMNs and 40 with AAMNs. We reviewed their medical records as well as their clinical and dermoscopic findings. Congenital acral melanocytic nevis were more asymmetrical than AAMNs (P=0.002) and presented more frequently as comma-shaped (P=0.005). Regarding dermoscopic findings, globular pattern (55.8%) was the most common feature of CAMNs, while parallel furrow pattern (37.5%) was the most common feature of AAMNs. The presence of fibrillar, globular, and parallel ridge patterns, and diffuse multi-component pigmentation differed significantly between the groups (P<0.05). Furthermore, CAMNs showed melanoma-specific dermoscopic patterns, such as parallel ridge (18.6%) and diffuse multi-component pigmentation (25.6%). The dermoscopic patterns of CAMNs and AAMNs differed markedly. In terms of dermoscopic patterns, CAMNs resembled acral melanoma more often than AAMNs did.

Clinical and Histopathologic Characteristics of Melanocytic Lesions on the Volar Skin Without Typical Dermoscopic Patterns

ImportanceIt is challenging to differentiate melanoma from melanocytic nevus on the volar skin in the absence of typical dermoscopic patterns.ObjectiveTo identify the frequency and clinical and dermoscopic characteristics of melanocytic lesions on the volar skin not displaying a parallel furrow pattern, lattice-like pattern, fibrillar pattern, or parallel ridge pattern on results of dermoscopy.Design, Setting, and ParticipantsIn this retrospective cohort study, a total of 504 melanocytic lesions on the volar skin were evaluated in the Shinshu University Hospital department of dermatology between January 1, 2000, and December 31, 2012. Dermoscopic images were independently assessed by 3 dermoscopists for the presence of established dermoscopic criteria. Statistical analysis was performed from October 1, 2017, to April 30, 2018.Main Outcomes and MeasuresFrequency of dermoscopic criteria and corresponding clinical (patient age and size and location of lesion) and histopathologic features.ResultsOf 504 lesions, 110 (21.8%) (melanocytic nevus, 97; melanoma, 8; and equivocal melanocytic lesion, 5) from 108 patients (68 female and 40 male patients; mean age, 40.1 years [range, 1-86 years]) did not show a parallel furrow pattern, lattice-like pattern, fibrillar pattern, or parallel ridge pattern. Among them, the mean patient age was significantly higher for melanoma than for melanocytic nevus (65.3 vs 38.0 years; P < .001), as was mean maximum lesion diameter (11.8 vs 5.7 mm; P < .001). Melanomas and equivocal melanocytic lesions tended to be distributed on weight-bearing areas of the foot sole, such as the heel, while nevi were spread over non–weight-bearing regions. Dermoscopically, 95 melanocytic nevi (97.9%) were symmetrical in 1 or 2 axes while melanomas were not. A total of 91 melanocytic nevi (93.8%) had 1 or 2 colors per lesion, and 4 melanomas (50.0%) had more than 2 colors. Vascular structures were seen in 3 melanocytic nevi (3.1%) and 3 melanomas (37.5%). Blue-white structures were seen in 18 melanocytic nevi (18.6%) and 3 melanomas (37.5%). Dots and globules were seen in 22 melanocytic nevi (22.7%) and 4 melanomas (50.0%). Vascular structures, blue-white structures, and dots and globules were irregularly distributed in the melanomas. Ulcer, hyperkeratosis, and irregular streaks were observed only in melanomas.Conclusions and RelevanceMore than one-fifth of melanocytic lesions on the volar skin did not display typical dermoscopic patterns. Asymmetry, numerous colors (≥3), and other melanoma-specific dermoscopic findings were more frequently observed for melanomas. Clinical information, including patient age and lesion size and location, was helpful in differentiating melanoma from melanocytic nevus. Further prospective clinical studies are warranted to clarify the diagnostic accuracy of dermoscopy combined with clinical information.

Subcorneal hematoma as an imitator of acral melanoma: Dermoscopic diagnosis.

OBJECTIVE:There are few studies investigating dermoscopic features of subcorneal hematoma, which is one of the imitators of acral melanoma. In this study, we aimed to describe dermoscopic findings of SH which will facilitate the diagnosis by reducing the use of invasive procedures.METHODS:This study included patients with subcorneal hematoma. Clinical, demographic and dermoscopic findings of all the patients were retrospectively reviewed. The diagnosis of subungual hematoma was confirmed using a positive scratch test in all of the patients.RESULTS:The findings showed that red-black (n=9, 45%) was the most common dermoscopic color followed by brown (n=4, 20%), red (n=3, 15%), black (n=2, 10%), brown-black (n=1, 5%) and red-brown (n=1, 5%). The most common pigmentation pattern was homogenous pattern (n=13, 65%). Eleven (55%) lesions showed globular pattern and eight (40%) lesions exhibit parallel ridge pattern. Eight (40%) lesions showed a combination of homogenous and globular patterns. The globules were disconnected from the homogenous pigmentation in six lesions. In two (10%) lesions, the globules were localized over the homogenous pigmentation.CONCLUSION:The presence of homogenous red to brown to black pigmentation combined with globules may lead to the correct diagnosis in a subcorneal hematoma. Scratch test may be a practical and minimal invasive diagnostic option to confirm the diagnosis in suspicious cases. To our knowledge, this is the most comprehensive study focusing on the dermoscopic aspect of the subcorneal hematoma.

A cross-sectional study of sweat-induced dermatitis during a South Indian summer: a glimpse of sweat gland-mediated cutaneous inflammation.

The role of sweat gland in inflammation has not received sufficient attention. The thermal stress during the summer months in tropical areas provides an opportunity to study the morphological patterns of inflammation produced primarily by the sweat gland. To collect clinical data on sweat-induced dermatitis during the summer months. A hospital-based descriptive cross-sectional study was done during the hot and humid summer months of April to June in a tertiary care institute in Puducherry. Patients clinically diagnosed with sweat-induced dermatitis (dermatitis primarily due to retention or extravasation of sweat) were included in the study. A detailed history was taken, and clinical examination was done. One hundred and fifty patients were included in the study. Various typical and atypical manifestations of sweat-induced dermatitis were seen. "Sweat dermatitis" presenting with dry, hyperpigmented, fissured "parchment"-like skin, shiny "crinkled cellophane paper"-like skin, or asymptomatic hyperpigmented macules was seen. Other atypical presentations included miliaria pustulosa with "hypopyon sign" and "linear and parallel ridge pattern" of dermatitis in patients with miliaria rubra affecting the lower neck and upper chest. A wide spectrum of sweat-induced dermatitis was seen during the summer months in a tropical region. It reflects the role of the sweat gland in cutaneous inflammation. An increased awareness of atypical manifestations is needed.