Preliminary Clinical Experience with a Novel Optical–Ultrasound Imaging Device on Various Skin Lesions

A compact handheld skin ultrasound imaging device has been developed that uses co-registered optical and ultrasound imaging to provide diagnostic information about the full skin depth. The aim of the current work is to present the preliminary clinical results of this device. Using additional photographic, dermoscopic and ultrasonic images as reference, the images from the device were assessed in terms of the detectability of the main skin layer boundaries and characteristic image features. Combined optical-ultrasonic recordings of various types of skin lesions (melanoma, basal cell carcinoma, seborrheic keratosis, dermatofibroma, naevus, dermatitis and psoriasis) were taken with the device (N = 53) and compared with images captured with a reference portable skin ultrasound imager. The investigator and two additional independent experts performed the evaluation. The detectability of skin structures was over 90% for the epidermis, the dermis and the lesions. The morphological and echogenicity information observed for the different skin lesions were found consistent with those of the reference ultrasound device and relevant ultrasound images in the literature. The presented device was able to obtain simultaneous in-vivo optical and ultrasound images of various skin lesions. This has the potential for further investigations, including the preoperative planning of skin cancer treatment.

Pigmented Lesions of the Eyelid Margin

The eyelid area poses a diagnostic and therapeutic challenge due to its specific anatomy. The eyelid is composed of skin, orbicularis muscle, tarsus, and the eyelid margin is continuous with palpebral conjunctiva. Among pigmented tumors, benign lesions such as epidermal or intradermal nevi, freckles, lentigo, or seborrheic keratosis are the most common. Melanoma is relatively rare in this location. A suspicious lesion may be biopsied or excised. Surgery in the eyelid area requires special considerations to maintain a safe surgical margin, vital function of the eyelid, and acceptable cosmetic effect due to the exposure of the eyelid region of the face.

Characterizing Malignant Melanoma Clinically Resembling Seborrheic Keratosis Using Deep Knowledge Transfer

Malignant melanomas resembling seborrheic keratosis (SK-like MMs) are atypical, challenging to diagnose melanoma cases that carry the risk of delayed diagnosis and inadequate treatment. On the other hand, SK may mimic melanoma, producing a ‘false positive’ with unnecessary lesion excisions. The present study proposes a computer-based approach using dermoscopy images for the characterization of SΚ-like MMs. Dermoscopic images were retrieved from the International Skin Imaging Collaboration archive. Exploiting image embeddings from pretrained convolutional network VGG16, we trained a support vector machine (SVM) classification model on a data set of 667 images. SVM optimal hyperparameter selection was carried out using the Bayesian optimization method. The classifier was tested on an independent data set of 311 images with atypical appearance: MMs had an absence of pigmented network and had an existence of milia-like cysts. SK lacked milia-like cysts and had a pigmented network. Atypical MMs were characterized with a sensitivity and specificity of 78.6% and 84.5%, respectively. The advent of deep learning in image recognition has attracted the interest of computer science towards improved skin lesion diagnosis. Open-source, public access archives of skin images empower further the implementation and validation of computer-based systems that might contribute significantly to complex clinical diagnostic problems such as the characterization of SK-like MMs.

Erbium Laser for Skin Surgery: A Single-Center Twenty-Five Years’ Experience

(1) Introduction: The Erbium laser is a very versatile laser system used in dermatology. Its ability to be almost selectively absorbed by water makes it a perfect device for managing various cutaneous skin conditions. (2) Methods: In this paper, we report our twenty-five years’ experience with the Erbium laser. More than three thousand patients were treated for common skin disorders such as flat warts, seborrheic keratosis, xanthelasmas, and scars. (3) Results: A complete response was observed in 89.6%, without significant side effects. Local anesthesia was used in only a tiny percentage of patients. (4) Conclusions: This study confirms that the Erbium laser is a valuable and flexible procedure for laser surgery with excellent safety and short healing times.

Upregulated Guanine Deaminase Is Involved in Hyperpigmentation of Seborrheic Keratosis via Uric Acid Release

Seborrheic keratosis, which is a benign tumor composed of epidermal keratinocytes, develops common in the elderly. Uric acid generated by upregulated guanine deaminase (GDA) has been identified to cause UV-induced keratinocyte senescence in seborrheic keratosis. Seborrheic keratosis is also frequently pigmented. Growing evidences indicate that hyperuricemia is a risk factor of acanthosis nigricans, an acquired skin hyperpigmentation. The objective of this study was to investigate role of GDA and its metabolic end product, uric acid, in hyperpigmentation of patients with seborrheic keratosis using their lesional and non-lesional skin specimen sets and cultured primary human epidermal keratinocytes with or without GDA overexpression or uric acid treatment. GDA-overexpressing keratinocytes or their conditioned media containing uric acid increased expression levels of MITF and tyrosinase in melanocytes. Uric acid released from keratinocytes was facilitated by ABCG2 transporter with the help of PDZK1 interaction. Released uric acid was taken by URAT1 transporter in melanocytes, stimulating melanogenesis through p38 MAPK activation. Overall, GDA upregulation in seborrheic keratosis plays a role in melanogenesis via its metabolic end product uric acid, suggesting that seborrheic keratosis as an example of hyperpigmentation associated with photoaging.

ANATOMOCLINICAL CONFRONTATION BETWEEN MELANOMA, SOLAR LENTIGO AND SEBORRHEIC KERATOSIS: A CASE REPORT

The primary diagnosis in case of a rapidly developing facipigmented lesion in an elderly patient is Dubreuilhs melanoma . This case report is highlighting the issue of anatomoclinical confrontation between a clinically suspected melanoma and a pathologically confirmed solar lentigo and seborrheic keratosis.