[Basal cell carcinoma and rare form variants]

Dermatological guide for primary care physicians: full body skin checks, skin cancer detection, and patient education on self-skin checks and sun protection

Dermatological conditions and skin cancers are common health concerns that require early detection and intervention. Primary care physicians play a crucial role in recognizing these conditions and serving as the first line of defense against skin cancers. This guide provides a systematic approach to conducting thorough skin examinations and enhancing understanding of common presentations of precancerous and cancerous lesions. We emphasize the importance of performing annual full-body skin exams to facilitate early detection and management of skin conditions, including a step-by-step, systematic protocol for conducting these exams, comprising preparing the patient, documenting findings, educating the patient, and considering biopsy or referral for suspicious lesions. Furthermore, we explore the atypical features of skin lesions that raise clinical suspicion and warrant further investigation. We describe the characteristics of common skin cancers, such as basal cell carcinoma, squamous cell carcinoma, and melanoma. We stress the importance of patient education on self-skin checks and sun protection measures. By incorporating the knowledge and skills presented in this guide, primary care physicians can confidently perform thorough full-body skin checks, identify common dermatological findings and early signs of skin cancers, and provide comprehensive care to patients. This will help ensure optimal outcomes in dermatological health.

Pagetoid Spread in Basal Cell Carcinoma: Potential for Misdiagnosis

ABSTRACT

Basal cell carcinomas are one of the most common cutaneous carcinomas and show classical histologic features of basaloid nests with peripheral palisading. Pagetoid and intraepidermal spread has not been described in basal cell carcinoma to the best of our knowledge. We report 5 cases of basal cell carcinoma with classic histologic patterns and overlying basaloid nests and single intraepidermal tumor cells. A panel of immunostains were performed that included CK7, MOC31, CEA-m, EMA, androgen receptor, and Bcl2. Most of our cases were positive for both MOC31 and CK7, and all cases were negative for CEA-m and EMA excluding extramammary Paget disease, one of the most common differential diagnoses. These cases expand the spectrum of findings that can be seen in basal cell carcinoma and can help prevent misdiagnoses of basal cell carcinomas as more aggressive tumors.

Deeply Supervised UNet for Semantic Segmentation to Assist Dermatopathological Assessment of Basal Cell Carcinoma

Accurate and fast assessment of resection margins is an essential part of a dermatopathologist's clinical routine. In this work, we successfully develop a deep learning method to assist the dermatopathologists by marking critical regions that have a high probability of exhibiting pathological features in whole slide images (WSI). We focus on detecting basal cell carcinoma (BCC) through semantic segmentation using several models based on the UNet architecture. The study includes 650 WSI with 3443 tissue sections in total. Two clinical dermatopathologists annotated the data, marking tumor tissues' exact location on 100 WSI. The rest of the data, with ground-truth sectionwise labels, are used to further validate and test the models. We analyze two different encoders for the first part of the UNet network and two additional training strategies: (a) deep supervision, (b) linear combination of decoder outputs, and obtain some interpretations about what the network's decoder does in each case. The best model achieves over 96%, accuracy, sensitivity, and specificity on the Test set.

Basal Cell Carcinoma: From Pathophysiology to Novel Therapeutic Approaches

Basal cell carcinoma (BCC) is the most common human cancer worldwide, and is a subtype of nonmelanoma skin cancer, characterized by a constantly increasing incidence due to an aging population and widespread sun exposure. Although the mortality from BCC is negligible, this tumor can be associated with significant morbidity and cost. This review presents a literature overview of BCC from pathophysiology to novel therapeutic approaches. Several histopathological BCC subtypes with different prognostic values have been described. Dermoscopy and, more recently, reflectance confocal microscopy have largely improved BCC diagnosis. Although surgery is the first-line treatment for localized BCC, other nonsurgical local treatment options are available. BCC pathogenesis depends on the interaction between environmental and genetic characteristics of the patient. Specifically, an aberrant activation of Hedgehog signaling pathway is implicated in its pathogenesis. Notably, Hedgehog signaling inhibitors, such as vismodegib and sonidegib, are successfully used as targeted treatment for advanced or metastatic BCC. Furthermore, the implementation of prevention measures has demonstrated to be useful in the patient management.

Dermatopathology 101. Part 2 - Skin tumors

The present CME article highlights fundamental aspects with respect to the histopathology of the most common skin tumors (epidermal, adnexal, melanocytic, and mesenchymal), their laboratory workup, as well as the importance of supplementary immunohistochemical and molecular studies. The information provided is meant to assist experienced clinicians in choosing the correct biopsy technique and in interpreting dermatopathology reports, and to provide dermatology residents with a better understanding of dermatopathology. Similar to inflammatory dermatoses, the diagnosis of skin tumors, too, requires the close cooperation between clinicians and dermatopathologists. The diagnostic quality and the resultant therapeutic approach can be significantly improved if this collaboration is based on the same dermatological understanding.