Pigmented Macules on the Head and Neck: A Systematic Review of Dermoscopy Features

Dermoscopy-based Radiomics Help Distinguish Basal Cell Carcinoma and Actinic Keratosis: A Large-scale Real-world Study Based on a 207-combination Machine Learning Computational Framework

This study has used machine learning algorithms to develop a predictive model for differentiating between dermoscopic images of basal cell carcinoma (BCC) and actinic keratosis (AK). We compiled a total of 904 dermoscopic images from two sources - the public dataset (HAM10000) and our proprietary dataset from the First Affiliated Hospital of Dalian Medical University (DAYISET 1) - and subsequently categorised these images into four distinct cohorts. The study developed a deep learning model for quantitative analysis of image features and integrated 15 machine learning algorithms, generating 207 algorithmic combinations through random combinations and cross-validation. The final predictive model, formed by integrating XGBoost with Lasso regression, exhibited effective performance in the differential diagnosis of BCC and AK. The model demonstrated high sensitivity in the training set and maintained stable performance in three validation sets. The area under the curve (AUC) value reached 1.000 in the training set and an average of 0.695 in the validation sets. The study concludes that the constructed discriminative diagnostic model based on machine learning algorithms has excellent predictive capabilities that could enhance clinical decision-making efficiency, reduce unnecessary biopsies, and provide valuable guidance for further treatment.

A Systematic Review of Diagnoses with Rosettes Under Dermoscopy

INTRODUCTION

Rosettes are a cluster of shiny white dots in the shape of a four-leaf clover seen under polarized dermoscopic light. Historically, rosettes were primarily reported in actinic keratoses and squamous cell carcinoma. However, rosettes have also been reported in other conditions.

OBJECTIVES

The objective of this systematic review to elucidate the breadth of diagnoses exhibiting this unique dermoscopic phenomenon.

METHODS

A review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Literature searches were performed in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science, as well as a manual search of the reference lists of screened articles.

RESULTS

A total of 73 articles met the inclusion criteria. Out of these, 47 distinct diagnoses with rosette were identified. Among neoplastic conditions, keratinizing neoplasms had the highest number of articles reported (N = 19). Discoid lupus was the most commonly reported diagnosis within the inflammatory category (N = 6). Molluscum contagiosum was the predominant diagnosis among infectious entities (N = 3), while acroangiodermatitis was the sole diagnosis reported in the vascular category (N = 1).

CONCLUSIONS

These findings confirm rosettes are not specific to keratinocytic growths and are observed in a wide range of conditions. Knowledge of the breadth of conditions with rosettes may aid clinicians when developing a differential diagnosis of a growth or an eruption with rosettes under dermoscopy.

Photodynamic Therapy is an Effective Treatment of Facial Pigmented Actinic Keratosis

BACKGROUND

Actinic keratosis (AK), or solar keratosis, is a precancerous condition of the skin, mainly caused by excessive and chronic exposure to ultraviolet radiation. Pigmented AK (pAK) is a rare variant of AK. Photodynamic therapy (PDT) is widely used to treat the classical variant of AK, but very limited data are available on the use of PDT in patients with pAK. The objective of this study was to assess the usefulness of PDT in the treatment of pAK.

METHODS

The study included 16 patients with 20 pAK lesions treated with PDT. All skin lesions were clinically and dermatoscopically assessed for typical features characteristic of pAK. Reflectance confocal microscopy (RCM) was also used to assess keratinocyte atypia, confirm pAK diagnosis, and rule out other disease entities.

RESULTS

After three PDT sessions, the complete resolution of all clinical features of pAK was observed in 80% of the studied lesions. Dermatoscopically, 65% of the lesions achieved 100% response and no cellular atypia was seen in the follow-up RCM images of 85% of lesions.

CONCLUSIONS

Photodynamic therapy is an effective treatment modality for pAK in fair-skinned individuals.