Pigmented Basal Cell Carcinoma Masquerading as a Melanoma

Pigmented basal cell carcinoma diagnosed in a dental setup: Report of a case with review of the literature

Pigmented basal cell carcinoma is a rare variant of basal cell carcinoma, with only a limited number of reported cases. Because of its similar clinical presentation, it is often over‐diagnosed as malignant melanoma. Along with case presentation, the clinical, microscopic features, and differential diagnosis are discussed in this case report.

Molecular Mechanisms and Targeted Therapies of Advanced Basal Cell Carcinoma

Among human cutaneous malignancies, basal cell carcinoma is the most common. Solid advances in unveiling the molecular mechanisms of basal cell carcinoma have emerged in recent years. In Gorlin syndrome, which shows basal cell carcinoma predisposition, identification of the patched 1 gene (PTCH1) mutation was a dramatic breakthrough in understanding the carcinogenesis of basal cell carcinoma. PTCH1 plays a role in the hedgehog pathway, and dysregulations of this pathway are known to be crucial for the carcinogenesis of many types of cancers including sporadic as well as hereditary basal cell carcinoma. In this review, we summarize the clinical features, pathological features and hedgehog pathway as applied in basal cell carcinoma. Other crucial molecules, such as p53 and melanocortin-1 receptor are also discussed. Due to recent advances, therapeutic strategies based on the precise molecular mechanisms of basal cell carcinoma are emerging. Target therapies and biomarkers are also discussed.

Basal cell carcinoma: Comprehensive clinical and histopathological aspects, novel imaging tools and therapeutic approaches (Review)

Basal cell carcinoma (BCC) is one of the most common malignant tumors worldwide, involving the skin. It is also part of keratinocyte carcinomas, alongside its squamous counterpart. It has low mortality and extremely low metastatic rates (although when present, it indicates a poor patient prognosis); it also has a high morbidity rate through local destruction and recurrence, particularly when perineural invasion is observed, clinically or histopathologically. BCC development is the result of environmental and patient factors, with genetics and ultraviolet radiation playing major roles. The clinical and histopathological aspects vary according to tumor subtype, being classified as high-risk tumors (nodular, superficial, pigmented and infundibulocystic BCC with adnexal differentiation) and fibroepithelial subtypes, or as high-risk tumors (micronodular, infiltrating, sclerosing/morphoeic and basosquamous subtype or the type with sarcomatoid differentiation). Dermoscopy is now complimented by novel in vivo diagnostic tools (optical coherence tomography, reflectance confocal microscopy, high-resolution ultrasonography, Raman spectroscopy or terahertz pulse imaging), improving the diagnostic accuracy and providing tumor depth and lateral margins without the use of invasive techniques. Novel treatment approaches for the treatment of BCC have recently been investigated with the use of hedgehog pathway inhibitors, such as Vismodegib. These approaches aim for complete resolution, minimal side-effects, high patient satisfaction with the optimal cosmetic results, particularly in key areas, such as the face. The present review article summarizes and discusses the comprehensive clinical and histopathological aspects of BCC, and presents novel imaging tools and therapeutic approaches that have been identified.

Dermoscopic features of neoplasms in skin of color: A review

BACKGROUND

Dermoscopy is undoubtedly a useful tool to improve diagnostic accuracy and minimize the number of unnecessary biopsies. However, much of the literature on dermoscopy focuses on findings in lighter-skin phototypes, leaving potential gaps of knowledge regarding its use in skin of color (SoC). As the clinical applications of dermoscopy continue to increase, understanding dermoscopic patterns in SoC is imperative.

OBJECTIVE

This review discusses the literature on dermoscopic findings of neoplasms in SoC, highlighting unique and characteristic dermoscopic features.

METHODS

A literature review was performed using the PubMed database. Case reports, case series, case-control studies, and systematic reviews were included.

RESULTS

A total of 8326 studies were identified based on the selected search terms, and 41 were included in this review based on relevance.

CONCLUSION

There are specific dermoscopic characteristics in SoC for benign nevi, acral lentiginous melanoma, ethnic melanonychia, and dermatofibroma; however, there is a lack of published data about specific features of cutaneous melanoma, subungual melanoma, pigmented basal cell carcinoma, and pigmented squamous cell carcinoma in SoC. Because pigmented basal cell carcinoma, pigmented squamous cell carcinoma, ethnic melanonychia, and acral lentiginous melanoma are diagnosed at later stages in this population, it is important to understand their dermoscopic features. Further descriptive studies are needed to better characterize unique dermoscopic features in neoplasms in SoC.

Multiple Skin Neoplasms at One Site (MUSK IN A NEST): A Comprehensive Review of Basal Cell Carcinoma and Benign or Malignant "Collision" Tumors at the Same Cutaneous Location

Multiple skin neoplasms at one site (MUSK IN A NEST), initially referred to as a collision tumor, describes the occurrence of two or more benign or malignant neoplasms that are adjacent or intermingled at the same cutaneous site. A mononeoplastic cutaneous tumor refers to a single tumor at any cutaneous site. Two, three, four, five, and six tumors at the same site are described as dineoplastic, trineoplastic, tetraneoplastic, pentaneoplastic, and hexaneoplastic cutaneous tumors, respectively; the prefixes are based on the numerical multiplier used by the International Union of Pure and Applied Chemistry (IUPAC). MUSK IN A NEST can be classified based upon their mechanism of pathogenesis-either being composed of mixed clones of cells (clonalium, which has three subtypes: collision, colonization, and combination) or the same clone of cells that has undergone clonal evolution (clonalidem, which has one subtype: biphenotypic). Basal cell carcinoma (BCC)-associated MUSK IN A NEST can be observed with either benign tumors, malignant tumors, or both. Nevi and seborrheic keratoses are the most common benign tumors associated with BCC; melanoma in situ and invasive melanoma are the most commonly reported malignant tumors associated with BCC. The definitive etiology of BCC-associated MUSK IN A NEST remains to be established-whether the development of the BCC at that site occurs as a direct or indirect consequence of the coexisting neoplasm or whether the occurrence of the BCC and the other neoplasm is merely the result of a coincidental juxtaposition of the tumors.