BACKGROUND: Numerous melanoma-specific dermoscopic features have been described in invasive melanomas, while fewer features are found in melanoma in situ (MIS) and atypical nevi (ATN). Consensus regarding which features are critical for the differentiation of MIS from ATN has not been reached.
OBJECTIVE: Determine 1) whether there are dermoscopic features that differentiate early MIS from ATN, and 2) whether non-invasive assessment of genomic biomarkers (LINC00518 and PRAME) can aid in patient management.
METHODS: From 2018 to 2023, 56 melanomas were evaluated for 5 clinical and 13 dermoscopic features and melanoma-associated genomic biomarkers. Two groups of ATN with positive and negative genomic biomarkers were randomly selected for comparison.
RESULTS: All melanomas in this study expressed one or both melanoma-associated genomic markers. MIS had an average of 3.90 (range, 2-7) of the 13 dermoscopic features, while invasive melanomas had an average of 4.44 (range, 3-6). Sixteen of 40 (40%) MIS and 3 of 16 (18.8%) invasive melanomas had 3 or fewer dermoscopic features. These findings were comparable to those observed in both ATN groups. The most common dermoscopic features were absent or diminished pigment network, regression structures, and granularity. This combination of features was most helpful in identifying lesions for genomic testing.
CONCLUSIONS: Clinical and dermoscopic features alone could not differentiate MIS from ATN. Non-invasive genomic testing helped differentiate lower from higher-risk lesions and aid in clinical management decisions. Genomic testing was particularly helpful in patients with large numbers of lesions with several being considered for biopsy based on clinical and dermoscopic examination. J Drugs Dermatol. 2024;23(9):717-723. doi:10.36849/JDD.8454.

Skin diseases manifesting as agminated pigmented lesions have overlapping clinical manifestations. Therefore, accurate differentiation is challenging. The clinical characteristics, histopathological findings, and treatment response of patients diagnosed with partial unilateral lentiginosis, nevus spilus, or linear and whorled nevoid hypermelanosis were retrospectively analysed. Each disease demonstrated distinct demographic and clinical characteristics, and the responses to laser treatment varied. The median age at onset varied significantly among the groups: 0.1, 6.6, and 0.5 years in patients with nevus spilus, partial unilateral lentiginosis, and linear and whorled nevoid hypermelanosis, respectively. Regarding the locations of the skin lesions, partial unilateral lentiginosis occurred predominantly on the head and neck, while approximately half of nevus spilus and linear and whorled nevoid hypermelanosis were observed on the extremities. Although linear and whorled nevoid hypermelanosis and partial unilateral lentiginosis share a similar histological feature of basal hyperpigmentation, patients with linear and whorled nevoid hypermelanosis showed the best response to laser treatment, while patients with partial unilateral lentiginosis demonstrated a poor treatment response. The study\'s data may provide important clues for the differential diagnosis and clinical decision-making regarding the treatment of these agminated pigmented lesions.

Phenylalanine is a crucial amino acid in the process of melanogenesis. However, the exact mechanism by which it is transported into melanocytes has not been disclosed. The aim of this study was to identify and examine the key transporters that are responsible for phenylalanine transportation and evaluate their significance in melanogenesis. The amino acid transporter SLC16A10 was found to be up-regulated in both melasma (GSE72140) and sun-exposed skin (GSE67098). The protein levels of SLC16A10 were proportional to the melanin content in melanocytic nevi, indicating that SLC16A10 was related to melanogenesis. After SLC16A10 overexpression, melanin increased significantly in MNT1 cells. Meanwhile, the expression of melanogenesis-related proteins such as TYR and TYRP1 increased, while their RNA levels did not change. Transcriptomics data indicated that SLC16A10 can enhance the function of ribosome. Furthermore, targeted metabolomics data and ELISA results demonstrated SLC16A10 mainly affected the transport of phenylalanine into the cells. Then, phenylalanine was added to the cell culture medium after SLC16A10 overexpression, melanin synthesis in cells furtherly increased, which verified that SLC16A10 enhances melanogenesis by promoting the uptake of phenylalanine. Finally, we found that SLC16A10 expression increased after UVB irradiation. Knockdown SLC16A10 reduced UVB-induced melanin production and phenylalanine uptake by cells. In summary, SLC16A10 enhances melanogenesis by promoting the uptake of phenylalanine, and upregulation SLC16A10 is likely responsible for the UVB-induced hyperpigmentation as well.

With rising melanoma incidence and mortality, early detection and surgical removal of primary lesions is essential. Multispectral imaging is a new, non-invasive technique that can facilitate skin cancer detection by measuring the reflectance spectra of biological tissues. Currently, incident illumination allows little light to be reflected from deeper skin layers due to high surface reflectance. A pilot study was conducted at the University Hospital Basel to evaluate, whether multispectral imaging with direct light coupling could extract more information from deeper skin layers for more accurate dignity classification of melanocytic lesions. 27 suspicious pigmented lesions from 23 patients were included (6 melanomas, 6 dysplastic nevi, 12 melanocytic nevi, 3 other). Lesions were imaged before excision using a prototype snapshot mosaic multispectral camera with incident and direct illumination with subsequent dignity classification by a pre-trained multispectral image analysis model. Using incident light, a sensitivity of 83.3% and a specificity of 58.8% were achieved compared to dignity as determined by histopathological examination. Direct light coupling resulted in a superior sensitivity of 100% and specificity of 82.4%. Convolutional neural network classification of corresponding red, green, and blue lesion images resulted in 16.7% lower sensitivity (83.3%, 5/6 malignant lesions detected) and 20.9% lower specificity (61.5%) compared to direct light coupling with multispectral image classification. Our results show that incorporating direct light multispectral imaging into the melanoma detection process could potentially increase the accuracy of dignity classification. This newly evaluated illumination method could improve multispectral applications in skin cancer detection. Further larger studies are needed to validate the camera prototype.

UNASSIGNED: Melanocytic nevi can show a great number of morphological, cytoarchitectural, and stromal variations. Some of these histopathological patterns, infrequent or unusual, can occasionally produce diagnostic doubts or problems. A 22-year-old female patient presented a poorly pigmented cutaneous polypoid lesion of the scalp. Histopathological examination showed an intradermal melanocytic nevus composed of aggregates, nests, and cords of benign melanocytes, with collagenous stroma and large lipomatous areas. In the lipidized portion of the lesion, nevus cells, arranged in clusters, nests, and cords, were intimately associated with mature-appearing adipocytes, CD34-positive spindle cells, Alcian Blue-positive fibromyxoid stroma, and eosinophilic collagen bundles, findings resembling those typically seen in spindle cell lipoma. Spindle cell lipomatous metaplasia, rarely observed in some benign nonmelanocytic skin lesions, can be considered an additional unusual, not previously described, stromal variation occurring in melanocytic nevi.

Correlative imaging of cutaneous tumors provides additional information to the standard histopathologic examination. However, the joint progress in the establishment of analytical techniques, such as Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) in clinical practice is still limited. Their combination provides complementary information as it is also shown in our study in terms of major biotic (Ca, Mg, and P) and trace (Cu and Zn) elements. To elucidate changes in the elemental composition in tumors, we have compiled a set of malignant tumors (Squamous Cell Carcinoma, Basal Cell Carcinoma, Malignant Melanoma, and Epithelioid Angiosarcoma), one benign tumor (Pigmented Nevus) and one healthy-skin sample. The data processing was based on a methodological pipeline involving binary image registration and affine transformation. Thus, our paper brings a feasibility study of a practical methodological concept that enables us to compare LIBS and LA-ICP-MS results despite the mutual spatial distortion of original elemental images. Moreover, we also show that LIBS could be a sufficient pre-screening method even for a larger number of samples according to the speed and reproducibility of the analyses. Whereas LA-ICP-MS could serve as a ground truth and reference technique for preselected samples.

BACKGROUND: Melanocytic nevi (MN), warts, seborrheic keratoses (SK), and psoriasis are four common types of skin surface lesions that typically require dermatoscopic examination for definitive diagnosis in clinical dermatology settings. This process is labor-intensive and resource-consuming. Traditional methods for diagnosing skin lesions rely heavily on the subjective judgment of dermatologists, leading to issues in diagnostic accuracy and prolonged detection times.
OBJECTIVE: This study aims to introduce a multispectral imaging (MSI)-based method for the early screening and detection of skin surface lesions. By capturing image data at multiple wavelengths, MSI can detect subtle spectral variations in tissues, significantly enhancing the differentiation of various skin conditions.
METHODS: The proposed method utilizes a pixel-level mosaic imaging spectrometer to capture multispectral images of lesions, followed by reflectance calibration and standardization. Regions of interest were manually extracted, and the spectral data were subsequently exported for analysis. An improved one-dimensional convolutional neural network is then employed to train and classify the data.
RESULTS: The new method achieves an accuracy of 96.82 % on the test set, demonstrating its efficacy.
CONCLUSIONS: This multispectral imaging approach provides a non-contact and non-invasive method for early screening, effectively addressing the subjective identification of lesions by dermatologists and the prolonged detection times associated with conventional methods. It offers enhanced diagnostic accuracy for a variety of skin lesions, suggesting new avenues for dermatological diagnostics.

暂无摘要。

暂无摘要。

BACKGROUND: Childhood and adolescence are dynamic period in terms of nevogenesis, and the development and growth of new melanocytic nevus are frequently observed. In this study, the aim was to examine the pattern and diameter changes seen in the follow-up of pediatric melanocytic nevus.
OBJECTIVE: To describe the pattern and diameter changes seen in the follow-up of pediatric melanocytic.
METHODS: Our study involved the assessment of 301 pediatric melanocytic nevi in 50 patients attended at the Dermatology Clinic of Istanbul Training and Research Hospital between January 2008 and 2022. The pediatric melanocytic nevi were diagnosed clinically and dermoscopically. Subsequently, we conducted video-dermoscopic monitoring of these nevi over a span of 3 months to 3 years.
RESULTS: 46% of our patients were female (n = 23), with a mean age of 11.5 years. While the pattern of nevi was globular in 40% patients, the rate of globular pattern decreased to 30% in the follow-up. The basal homogeneous nevus pattern was seen in 10% patients, but was detected in 13.9% in the follow-up. Peripheral globules were observed in 19.3% of the cases, but in the follow-up, 61.1% of the globules regressed completely. Nevus excision was indicated in only 11 of 301 nevi.
CONCLUSIONS: Single-center study and a small of studies available on this subject.
CONCLUSIONS: Pediatric melanocytic nevi can show dynamic changes compared to nevi in adults. In this study, growth rates, dermoscopic features, and pattern changes seen in the follow-up of melanocytic nevi were evaluated. The globular pattern was observed most frequently. The presence of peripheral globules is frequently observed in pediatric melanocytic nevi with regression during the follow-up period.