Line-field Confocal Optical Coherence Tomography Research Articles

Comparing Line-Field Confocal Optical Coherence Tomography and Reflectance Confocal Microscopy on the In Vivo Healing Process of Lesions Induced by Fractional Photothermolysis.

The advent of ablative fractional photothermolysis has revolutionized laser dermatology by providing a method to produce well-standardized, precise, and repeatable microscopic lesions. These wounds typically heal within 1-3 weeks, depending on the body site, with a minimal risk of permanent scarring. This positions ablative fractional photothermolysis as an exemplary in vivo model for studying the skin's wound healing processes. This study aims to evaluate and compare the effectiveness of two noninvasive imaging techniques, reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT), in assessing skin wound healing following microscopic injuries induced by ablative fractional photothermolysis. The forearms of participating volunteers were treated and ablated with a CO2-Laser in a fractional pattern using varying power settings (2.5-10 mJ/MTZ). In vivo RCM and LC-OCT images were obtained at predefined time intervals post-laser treatment, ranging from 6 h to 14 days. Vertical visualization of the lesions through both imaging modalities revealed a healing process characterized by the upward and outward movement of microscopic epidermal necrotic debris, thereby reducing the depth of the injury while forming an external crust. LC-OCT imaging demonstrated more comprehensive results with fewer movement artifacts. Conversely, horizontal visualization with both techniques highlighted a gathering of keratinocytes around the wounds, indicating the initiation of the regenerative process. RCM provided superior image clarity in this horizontal plane. RCM and LC-OCT offer valuable and complementary noninvasive alternatives to conventional biopsy methods for the assessment and characterization of the skin's wound healing process post-ablative fractional photothermolysis. These findings underscore the potential of such imaging techniques in enhancing our understanding of the wound healing process. ClinicalTrials.gov identifier: NCT05614557.

Interobserver agreement on line-field confocal optical coherence tomography image markers in keratinocyte carcinomas and precursor lesions

Line-field confocal optical coherence tomography (LC-OCT) is a new technology for skin cancer diagnostics. However, the interobserver agreement (IOA) of known image markers of keratinocyte carcinomas (KC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), as well as precursors, SCC in situ (CIS) and actinic keratosis (AK), remains unexplored. This study determined IOA on the presence or absence of 10 key LC-OCT image markers of KC and precursors, among evaluators new to LC-OCT with different levels of dermatologic imaging experience. Secondly, the frequency and association between reported image markers and lesion types, was determined. Six evaluators blinded to histopathologic diagnoses, assessed 75 LC-OCT images of KC (21 SCC; 21 BCC), CIS (12), and AK (21). For each image, evaluators independently reported the presence or absence of 10 predefined key image markers of KCs and precursors described in an LC-OCT literature review. Evaluators were stratified by experience-level as experienced (3) or novices (3) based on previous OCT and reflectance confocal microscopy usage. IOA was tested for all groups, using Conger’s kappa coefficient (κ). The frequency of reported image marker and their association with lesion-types, were calculated as proportions and odds ratios (OR), respectively. Overall IOA was highest for the image markers lobules (κ = 0.68, 95% confidence interval (CI) 0.57;0.78) and clefting (κ = 0.63, CI 0.52;0.74), typically seen in BCC (94%;OR 143.2 and 158.7, respectively, p < 0.001), followed by severe dysplasia (κ = 0.42, CI 0.31;0.53), observed primarily in CIS (79%;OR 7.1, p < 0.001). The remaining seven image-markers had lower IOA (κ = 0.06–0.32) and were more evenly observed across lesion types. The lowest IOA was noted for a well-defined (κ = 0.07, CI 0;0.15) and interrupted dermal-epidermal junction (DEJ) (κ = 0.06, CI -0.002;0.13). IOA was higher for all image markers among experienced evaluators versus novices. This study shows varying IOA for 10 key image markers of KC and precursors in LC-OCT images among evaluators new to the technology. IOA was highest for the assessments of lobules, clefting, and severe dysplasia while lowest for the assessment of the DEJ integrity.

Line-field confocal optical coherence tomography based on tandem interferometry with a focus-tunable lens.

This article introduces an innovative line-field confocal optical coherence tomography (LC-OCT) system based on tandem interferometry, featuring a focus-tunable lens for dynamic focusing. The principle of tandem interferometry is first recalled, and an analytical expression of the interferometric signal detected is established in order to identify the influence of key experimental parameters. The LC-OCT system is based on a Linnik-type imaging interferometer with a focus-tunable lens for focus scanning, coupled to a Michelson-type compensating interferometer using a piezoelectric linear translation stage for coherence plane scanning. The system achieves axial and lateral image resolutions of approximately 1 µm over the entire imaging depth (400 µm), in line with conventional LC-OCT. Vertical section images (B-scans) of skin acquired at 14.3 fps reveal distinguishable structures within the epidermis and dermis. Using refocusing and stitching, images of a tissue phantom were obtained with an imaging depth superior to 1.4 mm. The system holds promise for LC-OCT miniaturization, along with enhanced imaging speed and extended imaging depth.

Comparison of facial skin ageing in healthy Asian and Caucasian females quantified by in vivo line-field confocal optical coherence tomography 3D imaging.

Quantitative biomarkers of facial skin aging were investigated in 109 healthy Asian female volunteers, aged 20 to 70 years. In vivo 3D Line-field Confocal Optical Coherence Tomography (LC-OCT) imaging, enhanced by Artificial Intelligence (AI)-based quantification algorithms, was utilized to compute various metrics, including stratum corneum thickness (SC), viable epidermal (VE) thickness, and Dermal-Epidermal Junction (DEJ) undulation along with cellular metrics for the temple, cheekbone, and mandible. Comparison with data from a cohort of healthy Caucasian volunteers revealed similarities in the variations of stratum corneum and viable epidermis layers, as well as cellular shape and size with age in both ethnic groups. However, specific findings emerged, such as larger, more heterogeneous nuclei in both layers, demonstrated by an increase in nuclei volume and their standard deviation, and increased network atypia, all showing significant age-related variations. Caucasian females exhibited a flatter and more homogeneous epidermis, evidenced by a decreased standard deviation of the number of layers, and a less dense cellular network with fewer cells per layer, indicated by a decrease in cell surface density. Ethnicity-wise comparisons highlighted distinct biological features specific to each population. Asian individuals showed significantly higher DEJ undulation, higher compactness, and lower cell network atypia compared to their Caucasian counterparts across age groups. Differences in stratum corneum and viable epidermal thickness on the cheekbone were also significant. LC-OCT 3D imaging provides valuable insights into the aging process in different populations and underscores inherent biological differences between Caucasian and Asian female volunteers.

Epidermal renewal during the treatment of atopic dermatitis lesions: A study coupling line‐field confocal optical coherence tomography with artificial intelligence quantifications

AbstractObjectiveThis study explores the application of Line‐field Confocal Optical Coherence Tomography (LC‐OCT) imaging coupled with artificial intelligence (AI)‐based algorithms to investigate atopic dermatitis (AD), a common inflammatory dermatosis.Materials and methodsAD acute and chronic lesions (ADL) were compared to clinically healthy‐looking skin (ADNL). LC‐OCT was used noninvasively and in real‐time to image the skin of AD patients during flare‐ups and monitor remissions under topical steroid treatment for 2 weeks. Quantitative parameters were extracted from the images, including morphological and cellular‐level markers of epidermal architecture. A novel cellular‐level parameter, nuclei “atypia,” which quantifies the orderliness of epidermal renewal, was used to highlight abnormal maturation processes.ResultsCompared to healthy skin, AD lesions exhibited significant increases in both epidermal and stratum corneum (SC) thickness, along with a more undulated dermo‐epidermal junction (DEJ). Additionally, keratinocyte nuclei (KN) were larger, less compact, and less organized in lesional areas, as indicated by the atypia parameter. A higher degree of atypia was observed in chronic lesions compared to acute ones. Following treatment, all the parameters normalized to levels observed in healthy skin within 2 weeks, mirroring clinical improvements.ConclusionThis study provides insights into the quantification of epidermal renewal using a noninvasive imaging technique, highlighting differences between ADL/ADNL and acute/chronic lesions. It also presents the AD treatment mechanism, paving the way for future investigations on AD and other skin barrier function‐related conditions.

Line-Field Confocal Optical Coherence Tomography: A New Skin Imaging Technique Reproducing a "Virtual Biopsy" with Evolving Clinical Applications in Dermatology.

Line-field confocal optical coherence tomography is a novel technology able to reproduce a "virtual biopsy" of the skin. The aim of this review is to explore the application of line-field confocal optical coherence tomography (LC-OCT) in various skin diseases, covering skin cancers, inflammatory and infectious skin diseases, genetic diseases, cosmetic procedures, and less common disorders. Study selection was conducted based on LC-OCT and using pertinent MeSh terms, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from inception to March 2024; to evaluate the quality and risk of bias of studies, Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used. the search retrieved 154 papers according to the selection criteria; after removing publications by one or more of the exclusion criteria, a total of 96 studies were found to be suitable for the analysis. Increasing evidence supports the use of LC-OCT as an adjunctive diagnostic tool for the in vivo diagnosis of a variety of skin tumors. As this device can be considered a "bridge" between dermoscopy and histopathology, widening applications in numerous fields of clinical dermatology, including inflammatory skin disease treatment, presurgical mapping, cosmetic procedures, and monitoring of non-invasive therapies, have been explored.

The Usefulness of Line-Field Confocal Optical Coherence Tomography in Monitoring Epidermal Changes in Atopic Dermatitis in Response to Treatment: A Pilot Study.

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Due to its high prevalence, considerable morbidity, and chronicity, there is a need for the accurate in vivo evaluation of treatment efficacy. Line-field confocal optical coherence tomography (LC-OCT) is a new emerging imaging technique able to perform a non-invasive, real-time examination of the epidermis and the upper dermis. LC-OCT may represent a promising tool in the diagnosis and treatment follow-up of chronic eczematous skin diseases with barrier defects. We aimed to investigate the role of LC-OCT in the non-invasive monitoring of the treatment effect on five patients with severe atopic dermatitis during dupilumab treatment. LC-OCT imaging was performed on five patients (three women and two men) aged between 14 and 85 years old at the baseline and at 2, 4, and 6 weeks of treatment with dupilumab. The LC-OCT scans were performed at two sites, the lesional skin in the antecubital fossa and the extensor part of the arm, considered a control site on each patient for comparison. The captured images were later evaluated. Descriptive statistics and a t-test were used to compare the analyzed parameters over time and between involved atopic skin and clinically healthy skin. The LC-OCT imaging was able to detect the difference in stratum corneum (SC) thickness and quality and epidermal thickness (ET) and the changes before and after treatment with high accuracy. The main findings include a significant reduction in the epidermal and stratum corneum thickness and decreased epidermal spongiosis and inflammation, with better quality of the stratum corneum indicating restoration of its tightness at both lesional and control sites. This study demonstrates that clinical improvement of affected and unaffected atopic skin under dupilumab treatment correlates with the LC-OCT findings. LC-OCT represents a novel, non-invasive tool examining the in vivo skin barrier and inflammation and can help to monitor the treatment efficacy among patients with atopic dermatitis in daily practice.

Epidemiology and Risk Factors of Actinic Keratosis. What is New for The Management for Sun-Damaged Skin.

Actinic keratosis (AK) is considered a chronic skin disease mostly caused by long-term exposure to UV radiation and other risk factors such as immunosuppression, leading to an individual susceptibility for skin cancer manifestation. The treatment of AK is laborious and costly, and the incidence of skin cancer is forecasted to double until the year 2030 in an aging society.Risk factors in AK for malignant transformation in cutaneous squamous cell carcinoma (cSCC) are not fully understood, but studies suggest that histological features, such as atypia in the basal epidermal third and basal proliferation (PRO score) in AK play a pivotal role for development of malignancy. As the clinical appearance of AK does not correlate with the risk for malignancy, guidelines suggest treating every single AK lesion upon diagnosis. Skin imaging techniques, such as line-field confocal optical coherence tomography (LC-OCT) can help to provide an individual holistic follow-up for AK lesions by non-invasive visualization of atypia and basal proliferation. A follow-up for patients with AK may be critical for treatment success in terms of strengthening therapy adherence. When AK presents therapy refractory, cSCC manifests in nearly 30% of the cases after several years. Patients with AK suffering from field cancerization and immunosuppression are susceptible for a severe course of disease including metastasis and high mortality rates. Those vulnerable subgroups benefit from close skin cancer screening, early adequate treatment and chemoprevention, such as niacinamide or acitretin. Skin cancer prevention is substantial. Primary prevention should include chemical and physical UV-light protection and avoidance of indoor tanning. Secondary prevention is essential in high-risk populations, such as fair skin type elderly men and STORs. Tertiary prevention should comprise adequate treatment strategies to prevent therapy resistance, reoccurrence and cSCC, especially when field cancerization and immunosuppression are present.

Line-field confocal optical coherence tomography: Characteristic hints for the diagnosis of scarring alopecia due to lupus erythematodes: A preliminary study.

Lupus erythematosus (LE) is an inflammatory autoimmune disease, that can affect the skin to varying degree. In particular, discoid LE (DLE) and the rare form of lupus panniculitis/profundus are associated with scarring alopecia. The heterogeneity of the clinical, dermatoscopic, and histologic presentation poses a major challenge to the clinician in the diagnosis and differential diagnosis of other forms of scarring alopecia. While noninvasive imaging techniques using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) have proven to be helpful in the diagnosis of scarring alopecia in the context of LE, this study aimed to investigate line-field confocal OCT (LC-OCT) to identify characteristic features of cicatricial alopecia in LE. Fifteen patients with cicatricial alopecia in LE were included and the most affected/inflamed areas of the scalp were prospectively examined. In analogy to histopathology and previously reported criteria in RCM, all images were evaluated according to seven established criteria and underwent descriptive analyses. LC-OCT revealed characteristic features of cicatricial alopecia, such as lymphocytic interface dermatitis (14/15; 93.3%) and basal cell vacuolization (13/15; 86.7%). The most impressive feature was the occurrence of prominent hyperreflective fibers in 14/15 patients (93.3%). LC-OCT imaging can noninvasively detect morphologic criteria such as lymphocytic and vacuolar interface dermatitis of cicatricial alopecia due to LE. In particular, the presence of hyperreflective collagen fibers appears to be a characteristic easily recognizable feature that may facilitate differential diagnosis with other forms of cicatricial alopecia. Further studies are mandatory to differentiate other forms of scarring alopecia.

Line-Field Optical Coherence Tomography: Usefulness in the Non-Invasive Differential Diagnosis of Congenital Alopecia of Infancy.

Soon after birth, the clinical differential diagnosis between sebaceous of Jadassohn (NSJ), congenital triangular alopecia (CTA) and aplasia cutis congenita (ACC) may be challenging. A certain overlap of standard dermoscopic features can occur, especially in atypical cases, depending on scalp skin morphology and maturation age. The recently developed line-field confocal optical coherence tomography (LC-OCT) can provide morphological skin details with cellular resolution trough a rapid non-invasive examination. To assess the LC-OCT features of 6 cases of congenital alopecia of different aetiologies, with both typical and atypical clinical appearance. A non-invasive imaging examination combining standard dermoscopy, high-resolution videodermoscopy (HRVD) and LC-OCT was realized in 7 babies presenting for congenital alopecia with overlapping features, aged between 5 months and 5 years. Based on the specific LC-OCT features, and supported by HRVD features, a diagnosis of NSJ, congenital triangular alopecia (CTA) and AC) were made in 4, 2 and 1 case, respectively. The combined LC-OCT plus HRVD non-invasive imaging bring the advantage to have a real time diagnosis, to set the proper management and allows to avoid a skin biopsy in the perinatal age/first years of life at delicate skin site.

Line-field confocal optical coherence tomography for the differential diagnosis of porokeratosis from clinical simulators: a preliminary study.

Porokeratosis variants are relatively rare and can be clinically misdiagnosed with several common papulo-keratosic simulators. Line-field confocal optical coherence tomography (LC-OCT) is a new technology able to explore the skin in vivo up to 500µm depth. In this preliminary study we aimed to investigate the role of LC-OCT in the diagnosis of many porokeratosis variants. A total of 54 patients (28 was affected by one among 13 porokeratosis variants, 26 had a simulator condition) were examined at lesional and perilesional sites in vertical and horizontal view. We found an almost perfect interobserver agreement in LC-OCT images interpretation and a perfect correspondence with histologic slides. In addition, a series of morphologic in vivo and 3D features related to the cornoid lamella were detected by LC-OCT, not visible under histology. This device can be proposed for rapid bed-side non-invasive differentiation of porokeratosis variants from their simulators, possibly sparing incisional biopsy in doubtful cases.

The Role of Line-Field Confocal Optical Coherence Tomography in Detecting Extramammary Paget Disease Recurrences: A Pilot Diagnostic Study.

Extramammary Paget disease (EMPD) is an uncommon adenocarcinoma of apocrine gland-rich areas, presenting significant diagnostic challenges due to its nonspecific clinical appearance and frequent misidentification as benign, inflammatory skin conditions. Traditional diagnostic methods such as biopsy are invasive and uncomfortable, often required repeatedly due to high recurrence rates. Dermoscopy and non-invasive imaging techniques have been used but provide limited diagnostic accuracy due to their constraints in depth penetration and resolution. Recent advancements in imaging technologies, such as line-field confocal optical coherence tomography (LC-OCT), show promise in enhancing diagnostic precision while minimizing invasive procedures. LC-OCT merges high-resolution imaging with deep penetration capabilities, capturing detailed horizontal and vertical skin images akin to histopathology. This study evaluated the diagnostic performance of LC-OCT in detecting EMPD and its recurrence in 17 clinically suspicious anogenital regions, belonging to six patients. Data were collected prospectively at the patient's bedside by an LC-OCT expert with poor training for EMPD, and, then, reviewed retrospectively by an independent LC-OCT expert with adequate training for EMPD and no concerns about time. The prospective examination yielded 64.7% accuracy (11 true results out of 17 total cases), 71.4% sensitivity (10 true positives out of 14 actual positives), and 33.3% specificity (1 true negative out of 3 actual negatives). The retrospective analysis achieved 94.1% accuracy (16 true results out of 17 total cases), 100% sensitivity (14 true positives out of 14 actual positives), and 66.7% specificity (2 true positives out of 3 actual positives), with the only false positive case being a difficult-to-diagnose concomitant presentation of a lichen sclerosus et atrophicus. Despite the need for specialized training, our results suggest that LC-OCT represents a valuable tool for accurately identifying EMPD and improving its management by reducing unnecessary biopsies. Further studies are needed to standardize its clinical application.

Line-Field Confocal Optical Coherence Tomography for the Diagnosis of Skin Tumors: A Systematic Review and Meta-Analysis.

A line-field confocal optical coherence tomography (LC-OCT) combines confocal microscopy and optical coherence tomography into a single, rapid, easy-to-use device. This meta-analysis was performed to determine the reliability of LC-OCT for diagnosing malignant skin tumors. PubMed, EMBASE, Web of Science databases, and the Cochrane Library were searched for research studies in the English language from inception till December 2023. To assess quality and the risk of bias, the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used. The sensitivity and specificity of each study were calculated. The bivariate summary sensitivity and specificity were calculated using the linear mixed model. Five studies with 904 reported per lesion analyses in our study; the specificity and sensitivity ranged from 67% to 97% and 72% to 92%, respectively. The pooled specificity and sensitivity were 91% (95% CI: 76-97%) and 86.9% (95% CI: 81.8-90.8%), respectively. The summary sensitivity and specificity from the bivariate approach are 86.9% (95% CI: 81.8-90.8%) and 91.1% (95% CI: 76.7-97.0%), respectively. The area under the curve is 0.914. LC-OCT shows great sensitivity and specificity in diagnosing malignant skin tumors. However, due to the limited number of studies included in our meta-analysis, it is premature to elucidate the true potential of LC-OCT.

Integration of line-field confocal optical coherence tomography and in situ microenvironmental mapping to investigate the living microenvironment of reconstructed human skin and melanoma models

BackgroundIn tissue engineering, real-time monitoring of tumors and of the dynamics of the microenvironment within in vitro models has traditionally been hindered by the need to harvest the cultures to obtain material to analyze. Line-field confocal optical coherence tomography (LC-OCT) has proven to be useful in evaluating in vivo skin conditions, including melanoma, by capturing dynamic, three-dimensional (3D) information without the need for invasive procedures, such as biopsies. Additionally, the M-Duo Technology® developed by IMcoMET presents a unique opportunity for continuous in situ biomarker sampling, providing insights into local cellular behavior and interactions. ObjectiveThis study aimed to validate the non-destructive mapping capabilities of two advanced methodologies (LC-OCT by DAMAE Medical and M-Duo Technology® by IMcoMET) to investigate the living microenvironment of in vitro reconstructed human skin (RhS) and melanoma-RhS (Mel-RhS). MethodsLC-OCT and M-Duo Technology® were compared to conventional analysis of the RhS and Mel-RhS microenvironments. ResultsLC-OCT successfully visualized the distinct layers of the epidermis and tumor structures within the Mel-RhS, identifying keratinocytes, melanocytes, tumor nests, and fibroblasts. The M-Duo Technology® revealed differences in in situ cytokine (IL-6) and chemokine (CCL2, CXCL10, and IL-8) secretion between Mel-RhS and the control RhS. Notably, such differences were not detected through conventional investigation of secreted proteins in culture supernatants. ConclusionThe combination of LC-OCT's high-resolution imaging and M-Duo Technology®’s in situ microenvironmental mapping has the potential to provide a synergistic platform for non-invasive, real-time analysis, allowing for prolonged observation of processes within Mel-RhS models without the need for culture disruption.

Illuminating characteristic patterns of inflammatory dermatoses: A comprehensive dual-imaging approach using Optical coherence tomography and Line-field confocal optical coherence tomography.

Inflammatory skin diseases, such as psoriasis, atopic eczema, and contact dermatitis pose diagnostic challenges due to their diverse clinical presentations and the need for rapid and precise diagnostic assessment. While recent studies described non-invasive imaging devices such as Optical coherence tomography and Line-field confocal OCT (LC-OCT) as possible techniques to enable real-time visualization of pathological features, a standardized analysis and validation has not yet been performed. One hundred forty lesions from patients diagnosed with atopic eczema (57), psoriasis (50), and contact dermatitis (33) were imaged using OCT and LC-OCT. Statistical analysis was employed to assess the significance of their characteristic morphologic features. Additionally, a decision tree algorithm based on Gini's coefficient calculations was developed to identify key attributes and criteria for accurately classifying the disease groups. Descriptive statistics revealed distinct morphologic features in eczema, psoriasis, and contact dermatitis lesions. Multivariate logistic regression demonstrated the significance of these features, providing a robust differentiation between the three inflammatory conditions. The decision tree algorithm further enhanced classification accuracy by identifying optimal attributes for disease discrimination, highlighting specific morphologic criteria as crucial for rapid diagnosis in the clinical setting. The combined approach of descriptive statistics, multivariate logistic regression, and a decision tree algorithm provides a thorough understanding of the unique aspects associated with each inflammatory skin disease. This research offers a practical framework for lesion classification, enhancing the interpretability of imaging results for clinicians.

Line-field Confocal Optical Coherence Tomography (LC-OCT) for real-time differential diagnosis of toxic epidermal necrolysis versus staphylococcal scalded skin syndrome leading to an optimal initial management

We present here the cases of a 31-year-old male and a 68-year-old female, both presented with extensive erythema, a positive Nikolsky’s sign and major pain. Line-field Confocal Optical Coherence Tomography (LC-OCT) LC-OCT is a fast imaging tool able to visualize the cleavage level and epidermal necrosis to distinguish staphylococcal scalded skin syndrome from toxic epidermal necrolysis.

Line‐field confocal optical coherence tomography and optical coherence tomography for distinguishing basal cell carcinoma from dermal nevus: A case report

AbstractBasal cell carcinoma (BCC) is the most frequent skin cancer with a rising incidence. It can imitate benign lesions for example, dermal nevus clinically and dermoscopically. Both entities show specific morphologic features in line‐field confocal optical coherence tomography (LC‐OCT) and optical coherence tomography (OCT). The aim was to differentiate both lesions via noninvasive imaging to prevent unnecessary surgery. A 63‐year‐old woman presented with a light brownish nodule on the left cheek and a brownish nodule on the right nasal slope/cheek, which were both evident since a few months. The clinical and dermoscopic appearance of both lesions was very similar including the differential diagnosis of a dermal nevus or BCC. Dynamic OCT of the lesion on the left cheek showed multiple hyporeflective nodules in the dermis with hypervascularization. Using LC‐OCT several hyporeflective round to ovoid nodules with hyporeflective clefting embedded in a hyperreflective surrounding connective tissue could be observed. These specific morphological criteria called millefeuille pattern led to the diagnosis of a nodular BCC. The lesion of the right cheek presented with a thickened epidermis and elongated rete ridges in dynamic OCT. Upon LC‐OCT examination a so‐called large wave like pattern presenting as undulating hyporeflective and hyperreflective lobular structures could be identified. Therefore, the diagnosis of a dermal nevus was made. Both lesions were identified correctly as confirmed histopathologically after shave excision. Since BCC can imitate benign lesions for example, dermal nevi, the use of OCT and LC‐OCT can facilitate the identification of BCC and its imitators. Noninvasive imaging can help to avoid unnecessary biopsy especially in areas where the skin is vulnerable to punch biopsy.

Subclinical effects of botulinum toxin A and microwave thermolysis for axillary hyperhidrosis: A descriptive study with line-field confocal optical coherence tomography and histology.

Botulinum toxin A (BTX) and microwave thermolysis (MWT) are standard axillary hyperhidrosis treatments, but comparison of their subclinical effects is lacking. Line-field confocal optical coherence tomography (LC-OCT) is a promising non-invasive imaging tool for visualizing tissue-interactions. This study aimed to describe subclinical effects of BTX and MWT for axillary hyperhidrosis with LC-OCT-imaging compared to histology. This study derived from an intra-individual, randomized, controlled trial, treating axillary hyperhidrosis with BTX versus MWT. Subclinical effects based on LC-OCT images from baseline and 6-month follow-up (n = 8 patients) were evaluated and compared to corresponding histological samples. At baseline, LC-OCT visualized eccrine pores at the skin surface and ducts in the upper dermis (500 μm), but not deeper-lying sweat glands. Histology identified entire sweat glands. Six months post-treatment, LC-OCT revealed no detectable morphology changes in any BTX-treated axillae (100%), while recognizing obstructed eccrine pores and atrophy of eccrine ducts in most MWT-treated axillae (75%). Histology corroborated LC-OCT findings, while also showing substantial changes to entire sweat glands. LC-OCT enabled visualization of subclinical alterations of superficial eccrine ducts after MWT and unchanged morphology after BTX. LC-OCT is a promising tool for non-invasive assessment of treatment-specific tissue-interactions that can be complementary to histology.

Criteria for melanocytic lesions in LC-OCT.

Line-field confocal optical coherence tomography (LC-OCT) is an emerging diagnostic tool with imaging depth reaching ~400 μm and a novel three-dimensional (3D) cube providing cellular resolution. As far as we are aware, there are only a limited number of papers that have reported diagnostic criteria for melanocytic lesions using this technique, and none of them have been multicentric. Our aim was to establish the diagnostic criteria for melanocytic lesions using LC-OCT and identify the most significant architectural and cytologic features associated with malignancy. A retrospective evaluation of 80 consecutive melanocytic lesions from a prospective multicentric data set spanning three European centres was conducted. We excluded facial, acral and mucosal lesions from the study. Dermoscopic and LC-OCT images were evaluated by a consensus of four observers. Multivariate logistic regression with backward elimination was employed. The main melanoma diagnostic criteria include detecting >10 pagetoid cells in 3D acquisition, irregular 3D epidermal architecture, disrupted dermoepidermal junction (DEJ) and clefting. Significant risk factors were irregular 3D epidermal architecture, >10 pagetoid cells, dendritic cells at DEJ without underlying inflammation. Novel malignancy criteria in vertical view were DEJ disruption and clefting around atypical melanocyte nests. Exclusive melanoma features were epidermal nests, epidermal consumption, dense dermal nests with atypia. Protective features in the absence of any malignancy indicators were DEJ ring pattern, cobblestone, elongated rete ridges (vertical), well-defined DEJ and wave pattern (vertical). A series of diagnostic criteria for the identification of melanocytic lesions with LC-OCT have been established. Validation of these criteria in clinical practice through future studies is essential to further establish their utility.

Non-Invasive Diagnosis of Angioma Serpiginosum Plantaris: High-Resolution Dermoscopy, High-Frequency Ultrasound, and Line-Field Confocal Optical Coherence Tomography

We present a comprehensive study of acral serpiginous hemangioma, a rare vascular pathology. This distinctive manifestation was examined for the first time using high-resolution video dermoscopy (HRVD), high-frequency ultrasound (HFUS), and line-field confocal optical coherence tomography (LC-OCT). The combined application of these techniques provides new and detailed morphological features able to determine the in vivo structure of lesional skin. This innovative non-invasive approach emphasizes the importance of incorporating advanced diagnostic tools able to provide a virtual histology in order to avoid unnecessary biopsies in benign lesions, often causing pain and functional/aesthetic discomfort.