Concordance between reflectance confocal microscopy and histopathology for the diagnosis of acral lentiginous melanoma.

BACKGROUND: Acral lentiginous melanoma (ALM) is a highly malignant and invasive type of melanoma with unique locations of onset. Its incidence is increasing and early diagnosis is challenging. Reflectance confocal microscopy (RCM) is a non-invasive technique that provides an accurate image of tissue pathology. There are few reports on the use of RCM for the assessment of ALM. MATERIALS AND METHODS: In this retrospective study, data from 31 patients with a clinical diagnosis of ALM were collected. RCM image features were compared with histopathological findings to determine the concordance between the two methods. The sensitivity, specificity, positive predictive value, and negative predictive value of RCM for the diagnosis of ALM were evaluated. RESULTS: RCM and histopathology findings were concordant in 29 of 31 patients (93.5%). There were no false-negative results, although there were two false positives in RCM diagnosis. The sensitivity of RCM for diagnosing ALM was 100%, specificity was 50%, positive predictive value was 93.1%, and negative predictive value was 100%. CONCLUSIONS: RCM showed substantial concordance with histopathology in the diagnosis of ALM. It is a reliable and valuable non-invasive diagnostic tool that holds promise for the early diagnosis of ALM.

ETU-Net: edge enhancement-guided U-Net with transformer for skin lesion segmentation.

Objective.Convolutional neural network (CNN)-based deep learning algorithms have been widely used in recent years for automatic skin lesion segmentation. However, the limited receptive fields of convolutional architectures hinder their ability to effectively model dependencies between different image ranges. The transformer is often employed in conjunction with CNN to extract both global and local information from images, as it excels at capturing long-range dependencies. However, this method cannot accurately segment skin lesions with blurred boundaries. To overcome this difficulty, we proposed ETU-Net.Approach.ETU-Net, a novel multi-scale architecture, combines edge enhancement, CNN, and transformer. We introduce the concept of edge detection operators into difference convolution, resulting in the design of the edge enhanced convolution block (EC block) and the local transformer block (LT block), which emphasize edge features. To capture the semantic information contained in local features, we propose the multi-scale local attention block (MLA block), which utilizes convolutions with different kernel sizes. Furthermore, to address the boundary uncertainty caused by patch division in the transformer, we introduce a novel global transformer block (GT block), which allows each patch to gather full-size feature information.Main results.Extensive experimental results on three publicly available skin datasets (PH2, ISIC-2017, and ISIC-2018) demonstrate that ETU-Net outperforms state-of-the-art hybrid methods based on CNN and Transformer in terms of segmentation performance. Moreover, ETU-Net exhibits excellent generalization ability in practical segmentation applications on dermatoscopy images contributed by the Wuxi No.2 People's Hospital.Significance.We propose ETU-Net, a novel multi-scale U-Net model guided by edge enhancement, which can address the challenges posed by complex lesion shapes and ambiguous boundaries in skin lesion segmentation tasks.

Reflectance Confocal Microscopy Follow-up of Multifocal Superficial Basal Cell Carcinomas Treated With Imiquimod 5% Cream.

Introduction: Patients with multifocal superficial basal cell carcinomas (sBCC) require a non-invasive treatment and follow-up with a non-invasive technique. Imiquimod 5% cream is a new non-invasive therapy for BCC. Reflectance confocal microscopy (RCM) is a non-invasive, real-time imaging technique. Objectives: To evaluate and describe the feasibility and efficacy of imiquimod 5% cream for the treatment of multifocal sBCC using RCM. Methods: The efficacy of imiquimod 5% cream for the treatment of multifocal sBCC was evaluated, as well as the potential of RCM for assessing therapeutic effects. We reported four patients with 34 sBCC lesions were treated with imiquimod 5% cream. RCM was performed in the baseline and at 12 weeks, 24 weeks and 52 weeks after starting treatment. Results: Of 34 lesions treated with imiquimod 5%, 32 responded to the treatment and showed complete clinical clearing. Two subclinical BCC lesions were identified by RCM. The complete tumor clearance rate was 88.2%, and the efficiency rate was 97.1%. No lesion recurred at 24-month follow-up. RCM identified previously described confocal features of BCC and was more sensitive than clinical examination. Local skin reactions were relieved after expectant treatment. Conclusions: Imiquimod 5% cream may be useful for the treatment of multifocal sBCC, and its side effects are easy to manage. RCM can be used for non-invasive monitoring of treatment response and improved the tumor clearance rate.

Reflectance Confocal Microscopy for Identification of Vulvar Lichen Sclerosus et Atrophicus and Vitiligo.

ABSTRACT: Lichen sclerosus et atrophicus (LSA) is a chronic inflammatory disease. The clinical presentation is clustered distribution of porcelain white spots that can be fused together. Early diagnosis of LSA is difficult, especially in the vulva, where it is difficult to distinguish from vitiligo. Traditional diagnostic methods mainly rely on histopathology. In this study, we used reflectance confocal microscopy (RCM) to study the characteristics of LSA and vitiligo. We investigated the clinical and confocal features of 40 cases of histopathologically proven genital LSA or vitiligo, and correlated the features with histopathologic findings. Through the analysis of the results, by RCM, we can easily distinguish genital LSA from vitiligo, which are clinically indistinguishable. This can reduce the number of unnecessary biopsies, and help with early diagnosis and timely treatment.

The expression profiles of microRNAs in Kaposi's sarcoma.

Kaposi's sarcoma (KS) is a multicentric angioproliferative tumor of mesenchymal origin. The molecular and biologic aspects of KS are not fully understood. MicroRNAs are non-protein-coding small RNAs in the size range 19-25 nucleotides (nt) that play important roles in biological processes, including cellular differentiation, proliferation, and death. We performed a miRNA microarray analysis by detecting six paired KS and matched adjacent healthy tissues using the 7th generation of miRCURY(TM) LNA Array (v.18.0) (Exiqon) containing 3100 capture probes. We selected 10 significant differentially expressed miRNAs, which were confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) in 18 paired KS and matched adjacent healthy tissue specimens. We also investigated the associations between clinical features and miRNA expression. Among the 3100 human miRNA probes in the microarrays, we identified 170 differentially expressed miRNAs (69 upregulated and 101 downregulated miRNAs) in KS versus adjacent healthy tissues. Among the most significantly upregulated miRNAs were miR-126-3p, miR-199a-3p, miR-16-5p, and the 13 KSHV-related miRNAs. The most significantly downregulated miRNAs included miR-125b-1-3p and miR-1183. Eight upregulated miRNAs, miR-181b-5p, miR-199a-3p, miR-15a-5p, miR-126-3p, miR-1297, kshv-miR-k12-12-3p, kshv-miR-k12-1-5p, and miR-16-5p, and two downregulated miRNAs, miR-125b-1-3p and miR-1183, were confirmed by qRT-PCR in 18 paired KS samples. The qRT-PCR results for 10 miRNAs were consistent with our microarray results. The miR-125b-1-3p and miR-16-5p had statistically significant associations with HHV-8 and HIV infections in KS. The results of miRNA profiling showed that KS appears to have unique expression patterns when compared with paired adjacent healthy tissues, suggesting that deregulation of miRNAs plays an important role in the progression of KS. These differentially expressed miRNAs may provide novel diagnostic and prognostic tools.