INTRODUCTION: With the advancement of digital image analysis, predictive analysis, and machine learning methods, studies have emerged regarding the use of artificial intelligence in imaging tests such as dermoscopy.
OBJECTIVE: Construction, testing, and implementation of an artificial neural network based on characteristics of dermoscopic images.
METHODS: 1949 images of melanocytic nevi and melanomas were included, both from the authors’ files and from dermoscopic image banks available on the internet, and routines and plugins were developed to extract 58 features applied to a multilayered neural network construction algorithm. Also, 52 dermatologists assessed 40 random images and compared the results compared.
RESULTS: The training and testing of the neural network obtained a correct percentage of classification of 78.5% and 79.1%, respectively, with a ROC curve covering 86.5% of the area. The sensitivity and specificity of dermatologists were 71.8% and 52%. For the same images and a cutoff point of 0.4 (40%) of the output value, the application obtained 62% and 56% values, respectively.
CONCLUSIONS: Multilayer neural network models can assist in the dermoscopic evaluation of melanocytic nevi and melanomas regarding the differential diagnosis between them.

Keywords: Artificial intelligence; Diagnosis; Melanoma; Nevus

Malignant fibrous histiocytoma (MFH) or undifferentiated pleomorphic sarcoma (UPS) is a sarcoma capable of invading adjacent structures. It is a mesenchymal neoplasia that predominates in men between the sixth and seventh decades of life. It is located mainly in the lower limbs and may affect the head and neck, trunk, and retroperitoneum, presenting a tendency to recurrence and local metastasis. This report aims to present a case of MFH in the ankle of a 49-year-old woman with an adjacent bone invasion, which evolved with transtibial amputation. Clinical, radiological, histopathological, and therapeutic aspects were addressed, highlighting the importance of early diagnosis.

Keywords: Amputation; Malignant fibrous histiocytoma; Sarcoma

Eruptive vellus hair cyst is a rare and benign dermatological condition in the development of vellus-type hair follicles. It affects mainly children and young adults, and is characterized by multiple asymptomatic papules, especially on the trunk. We report the case of a 33-year-old white man who presented multiple erythematous papules and pustules located on the trunk for about five years, refractory to topical treatments for acne. Dermoscopy revealed oval lesions with eccentric exulceration and rare protruding filiform structures. We established the diagnosis of eruptive vellus hair cyst based on the findings of dermoscopy and histopathological examination.

Keywords: Cysts; Acneiform eruptions; HIV