Cutaneous melanoma is the most severe form of skin cancer. The incidence of the disease has been increasing in the last decades, largely due to increased ultraviolet radiation exposure. A comprehensive understanding of the complex biological processes involved in melanoma development and progression is essential for advancing patient care. Improvement in surveillance strategies, widespread use of sentinel lymph node biopsy, and breakthroughs in systemic therapy have all contributed considerably to enhancing patient outcomes and survival. Rapid advancements in melanoma management are expected to continue, particularly through innovations in molecular biology and genetics. These emerging technologies aim to enhance diagnostic accuracy, predict disease progression, and improve prognosis. Staying informed about these evolving developments is essential for professionals dealing with melanoma patients. This narrative review provides a comprehensive overview of the current state of cutaneous melanoma, covering fundamental areas, such as histopathology, genetics, epidemiology, diagnosis, and staging. It provides a foundation to enhance understanding of current treatment approaches and the principles behind emerging technologies. This review also highlights future directions in melanoma care, including improvements in neoadjuvant therapy, use of artificial intelligence-based algorithms, use of molecular biomarkers to improve diagnosis and prognosis, and development of personalized neoantigen mRNA vaccines. Ultimately, this review aims to support clinicians in understanding the current landscape and anticipated innovations in melanoma management to improve clinical decision-making.

Basosquamous carcinoma (BSC), an uncommon and aggressive nonmelanoma skin cancer exhibiting characteristics ranging from basal cell carcinoma (BCC) to squamous cell carcinoma (SCC), is a subject of controversy in terms of its classification, pathogenesis, histologic morphology, biologic behavior, prognosis, and management. This narrative review is based on an electronic search of English-language articles in PubMed that included the terms “basosquamous carcinoma” and/or “metatypical carcinoma of the skin” in their titles. The review aims to succinctly present and assess current data on the epidemiology, clinical presentation, dermoscopic, LC-OCT, and histopathologic characteristics, as well as the genetics and management of BSC, providing insight into this intriguing entity. As a conclusion, dermoscopy, deep incisional biopsies, and immunohistologic techniques should be applied in clinically suspicious lesions to achieve an early diagnosis and better prognosis of this tumor. Surgical treatments, including wide excision and Mohs’ micrographic surgery, remain the treatment of choice. Finally, Hedgehog pathway inhibitors and checkpoint inhibitors, must be thoroughly investigated with large controlled trials, since they may offer an alternative solution to irresectable or difficult-to-treat locally advanced cases of basosquamous carcinoma.

Cutaneous metastases represent 2% of all skin tumours. Their recognition can be challenging, as they may present with different clinical features, with consequent frequent delay and failure in diagnosis. To review our series of cutaneous metastatic lesions, analyse their frequency according to patient gender, histotype, localization of the primary tumour, and site of cutaneous metastasis, and correlate this data with clinicopathological parameters. We conducted a retrospective review of all cases of cutaneous metastases from visceral neoplasms diagnosed in our dermatopathology department from July 2003 to February 2017. We registered clinical, histological, and immunohistochemical data. Additional immunohistochemical staining panels were elaborated to confirm or identify the origin of the primary tumour, or at least to specify the histological subtype. We identified 45 histological diagnoses of cutaneous and mucocutaneous metastases. The primary tumour that was most likely to metastasize to the skin was breast cancer. Most cases of breast (89%) and lung cancer (86%) metastasized to the trunk. Of the lesions, 57.5% were nodules and 32.5% were plaques, more frequently multiple (64.4%). In 58% of cases, a metastasis was clinically suspected. Histological examination most frequently revealed an adenocarcinoma, sometimes suggestive of the site of origin. Cutaneous metastases should be primarily considered when discrete firm painless nodules emerge rapidly. Clinicians should carefully consider infiltrated lesions of the chest in women since scleroderma and erysipelas-like presentation can be a clue for undiagnosed breast cancer.

The global outbreak of human monkeypox virus (hMPXV1) in 2022 highlighted the usefulness of dermatological manifestations for its diagnosis. Infection by the human monkeypox virus thus necessitated inclusion in the diagnostic repertoire of dermatopathology. To assess the histopathological and microscopical findings of cutaneous lesions related to hMPXV infection, we analyzed skin biopsies from patients with positive MPXV DNA polymerase chain reaction presenting with a typical course of hMPXV1 infection. The most prominent histopathological findings were ascribable to a pustular stage in which epidermal necrosis with areas of non-viable keratinocytes and a “shadow cell” appearance were evident; in some cases, the deep portion of the hair follicle and the acrosyringial epithelium were affected. The main cytopathic modifications included ballooning keratinocytes, followed by Guarnieri bodies and a ground glass appearance of the keratinocytes’ nuclei, together with a dense mixed inflammatory cell infiltrate with prominent neutrophil exocytosis. Transmission electron microscopy analysis demonstrated viral particle aggregates in the cytoplasm of keratinocytes, without any involvement of the nucleus. Interestingly, we also found the presence of viral particles in infected mesenchymal cells, although to a lesser extent than in epithelial cells. Through this study, we contributed to expanding the histological and microscopic knowledge of the human mpox virus, a key step to understanding current and potential future trends of the disease, as well as of other Orthopoxvirus infections.