Polyomavirus-positive Merkel cell carcinoma: the beginning of the beginning.

Merkel cell carcinoma (MCC) is an aggressive, fast-growing, highly metastatic neuroendocrine skin cancer. The Merkel cell polyomavirus (MCPyV) is an oncogenic driver in the majority of MCC tumors. In this issue of the JCI, Hansen and authors report on their tracking of CD8+ T cells reactive to MCPyV T antigen (T-Ag) in the peripheral blood of 26 patients with MCC who were undergoing frontline anti-programmed cell death protein-1 (anti-PD-1) immunotherapy. They discovered unique T cell epitopes and used the power of bar-coded tetramers to portray immune checkpoint inhibitor-induced immunogenicity as a predictor of clinical response. These findings provide the foundation for therapeutic possibilities for MCC, including vaccines and adoptive T cell- and T cell receptor-driven (TCR-driven) treatments.

[Chinese guildeline on diagnosis and treatment of basal cell carcinoma (2023 edition)].

Basal cell carcinoma (BCC) is the most common skin malignancy, with a higher prevalence in Caucasians than in East Asians. Although there is a lack of epidemiological data in China, it is generally believed that the incidence of BCC in China is increasing due to the aging population. A variety of risk factors are related to the occurrence of BCC, among which ultraviolet rays and gene mutations play a major role, especially the abnormal activation of Hedgehog (Hh) signaling pathway, which is considered to be the most important pathogenesis of BCC. The clinical manifestations of BCC are highly specific, and most experienced doctors can make a preliminary diagnosis by clinical manifestations. Dermoscopy and other imaging methods can greatly improve the accuracy of diagnosis, but there are still some atypical or rare types of BCC that need further confirmation through histopathological examination. This guideline is initiated by the National Clinical Research Center for Skin and Immune Diseases (based on Peking University First Hospital). It has invited a panel of experts consisting of 24 senior dermatologists specializing in dermatologic surgery from the Dermatologic Surgery Group of the Chinese Medical Doctor Association of Dermatology, the Dermatologic Surgery Group of the Dermatology & Venereology Committee, Chinese Association of Integration Medicine, and the Dermatologic Surgery and Cosmetic Branch of Clina Leprosy Association. In addition, experts from the Burn and Plastic Surgery (Maxillofacial), Ophthalmology, Otolaryngology, Head and Neck Surgery, Radiation Therapy, and Pathology were also invited to participate. This panel forms the "Chinese Guideline for the Diagnosis and Treatment of Basal Cell Carcinoma" expert group. Based on the latest domestic and international research findings, the guideline was developed through four rounds of discussions by the expert group and revised to provide valuable references for clinical healthcare providers in the diagnosis and treatment of BCC.

Role of the NLRP1 inflammasome in skin cancer and inflammatory skin diseases.

Inflammasomes are cytoplasmic protein complexes that play a crucial role in protecting the host against pathogenic and sterile stressors by initiating inflammation. Upon activation, these complexes directly regulate the proteolytic processing and activation of proinflammatory cytokines interleukin (IL)-1ß and IL-18 to induce a potent inflammatory response, and induce a programmed form of cell death called pyroptosis to expose intracellular pathogens to the surveillance of the immune system, thus perpetuating inflammation. There are various types of inflammasome complexes, with the NLRP1 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-1) inflammasome being the first one identified and currently recognized as the predominant inflammasome sensor protein in human keratinocytes. Human NLRP1 exhibits a unique domain structure, containing both an N-terminal pyrin (PYD) domain and an effector C-terminal caspase recruitment domain (CARD). It can be activated by diverse stimuli, such as viruses, ultraviolet B radiation and ribotoxic stress responses. Specific mutations in NLRP1 or related genes have been associated with rare monogenic skin disorders, such as multiple self-healing palmoplantar carcinoma; familial keratosis lichenoides chronica; autoinflammation with arthritis and dyskeratosis; and dipeptidyl peptidase 9 deficiency. Recent research breakthroughs have also highlighted the involvement of dysfunctions in the NLRP1 pathway in a handful of seemingly unrelated dermatological conditions. These range from monogenic autoinflammatory diseases to polygenic autoimmune diseases such as vitiligo, psoriasis, atopic dermatitis and skin cancer, including squamous cell carcinoma, melanoma and Kaposi sarcoma. Additionally, emerging evidence implicates NLRP1 in systemic lupus erythematosus, pemphigus vulgaris, Addison disease, Papillon-Lefèvre syndrome and leprosy. The aim of this review is to shed light on the implications of pathological dysregulation of the NLRP1 inflammasome in skin diseases and investigate the potential rationale for targeting this pathway as a future therapeutic approach.

Epithelioid malignant peripheral nerve sheath tumour of the ulnar nerve around the elbow: a diagnostic and therapeutic challenge.

Epithelioid malignant peripheral nerve sheath tumour (EMPNST) is a rare histological subtype of malignant peripheral nerve sheath tumour (MPNST), accounting for 5% to 17% of MPNSTs. The clinical and MRI findings of EMPNST mimic those of nerve abscesses, similar to the presentation in Hansen's disease. We present one such case with this kind of diagnostic dilemma. Intraoperative findings suggest a tumour changed the course of management subsequently. The development of neurological deficits postoperatively after tumour resection was a reconstructive challenge. To provide motor power and sensation through a procedure that provides a complete functional outcome for a young patient, distal nerve transfers were chosen. This provided an improvement in the quality of life and hastened the neurological recovery of the involved limb. Level of evidence: V.

Use of preoperative and perioperative ex vivo dermoscopy for precise mapping of margins for standard surgical excision of primary basal cell carcinoma.

Background The utility of preoperative and perioperative dermoscopy in standard surgical excision for radical excision of primary basal cell carcinoma remain unexplored. Aims To evaluate the use of preoperative and perioperative dermoscopy for precise mapping of margins during standard surgical excision of primary basal cell carcinoma. Methods In this retrospective, observational study, 17 patients clinically diagnosed with various morphological subtypes of basal cell carcinoma were included. Data about previous history, clinical examination of lesions and regional lymph nodes and preoperative dermoscopy were retrieved. After standard surgical excision had been carried out as per mapping of lateral margins, all the excised surgical specimens were subjected to perioperative dermoscopy and later reconfirmed with histopathology. Results Seventeen patients with mean age of 60.82 ± 9.99 years and median disease duration of 14 months were analysed. Clinically, basal cell carcinomas were of pigmented superficial subtype [6 (35.3%)], followed by pigmented nodular [5 (29.4%)], nodulo-ulcerative [4 (23.5%)] and micro nodular [2 (11.8%)]. Mean extension of clinical margin after dermoscopy was 0.59 ± 0.52 mm. Mean pre-assessed depth of tumour and mean depth of tumour were 3.46 ± 0.89 mm and 3.49 ± 0.92 mm, respectively. No recurrence was reported. Frequently found pre-operative dermoscopic features were maple leaf like structures [6 (35%)], blue grey dots and globules [6 (35%)] and short fine telangiectasias [6 (35%)]. Commonly observed perioperative dermoscopic features were: (1) irregular band with brown-grey pigmentation of dots, globules, streaks and pseudopodia like extensions [3 (50%)]; (2) irregular band of pseudo granulomatous structureless vascular areas in psoriasiform pattern with diffuse white streaks in pseudopodia like manner [1 (50%)]; (3) irregular band of pseudo granulomatous structureless vascular areas in psoriasiform pattern with streaks of white pseudopodia like structureless areas [1 (50%)]. Limitation This was a single-centre study with a small sample size. Conclusion This study highlights significance of preoperative and perioperative dermoscopy for precise planning and radical excision of primary basal cell carcinoma by standard surgical excision.

Follicular mycosis fungoides: Clinicohistopathologic features and outcomes in a series of 12 Chinese cases.

Background Follicular mycosis fungoides is a distinct variant of mycosis fungoides with a broad clinical spectrum. Recently, many studies have indicated that follicular mycosis fungoides should be divided into different subtypes with disparate prognoses. Objective To define the clinicohistopathologic features and outcomes of follicular mycosis fungoides and to identify risk factors that may be related to the prognosis of Chinese patients with follicular mycosis fungoides. Materials and methods We conducted a single-centre retrospective study and reviewed the clinical, histopathologic and immunophenotypic data of 12 patients diagnosed with follicular mycosis fungoides between 2009 and 2020 in the Department of Dermatology of West China Hospital of Sichuan university. Results A total of 12 patients (seven males and five females) with a mean age of 30 ± 14 years (age range 16-55 years) were included. Scalp and face were the most common involved sites (100%). Follicular papules, acneiform lesions, plaques, and nodules, were the main clinical presentations. Histopathological findings were consistent with the classic manifestations of follicular mycosis fungoides, including folliculotropism, perifollicular and intrafollicular lymphocytic infiltrates and mucinous degeneration. Interferon α-1b was the most common treatment. Four patients died of follicular mycosis fungoides in three years. Notably, immunohistochemical analysis revealed a decreased number of CD20+ cells in the deceased patients. Limitations This is a retrospective evaluation with a small number of cases; further prospective studies are warranted to support our inferences. Conclusion Our patients were much younger than in previous studies. The observed difference in this cohort may be explained by race, in addition to the limited number of cases. A decreased number of B cells might be associated with a poor prognosis, and more studies are necessary to discover the role of B cells in follicular mycosis fungoides as well as in mycosis fungoides.

Clinical analysis of 20 cases of cutaneous extranodal NK/T-Cell lymphoma.

Background To investigate the clinical features, pathological features and prognostic factors of cutaneous extranodal natural killer/T-cell lymphoma (CENKTL). Methods A total of 20 cases with CENKTL from February 2013 to November 2021 were analysed retrospectively. Results The patients included 15 men and five women, and their ages ranged from 19 to 92 (median age of 61) years. The most common lesions were on the extremities, followed by the trunk. Histopathological examination showed atypical lymphocyte infiltrate in dermis and subcutaneous fat. The tumour tissue showed vascular proliferation, vascular occlusion, and coagulation necrosis. In situ hybridisation revealed that 20 patients were positive for Epstein-Barr virus-coding ribonucleic acid. Immunohistochemistry showed that the tumour cells were positive for CD3 (18/20 and 90%), CD56 (19/20 and 95%), T-cell intracellular antigen (TIA-1) (13/14 and 92.9%) and CD20 (5/20, 25%). About 20 patients were positive for Ki-67 with values of 30-90%. A total of 11 of the 20 patients died, and two patients were lost to follow-up. The 2-year overall survival was 24%, and the median overall survival was 17 months. Univariate analysis revealed that involvement of lymph nodes (P = 0.042) correlated with worse survival. Limitation This is a retrospective study design and has a limited number of patients. Conclusion CENKTL is rare and has a poor prognosis. Diagnosis is challenging due to non-specific clinical symptoms and histopathology results. A comprehensive judgement should be made based on related clinical manifestations and histopathological and molecular examination. Lymph node involvement is an independent prognostic factor for CENKTL.

The association between skin cancer and HIV infection.

Background People affected by Human Immunodeficiency Virus (HIV), are burdened by a higher risk of developing malignancies including non-melanoma skin cancer (NMSC) and melanoma skin cancer. Objective To evaluate the association of HIV with melanoma and NMSC at a University Hospital. Methods This is a cross-sectional retrospective study of HIV-infected and a matched comparison group, analyzing the associations between skin cancer and HIV infection. Results Compared to the HIV-uninfected, HIV-infected had 80% association with skin cancer (CI 95%: 1.3-2.4, P = 0.001) The risk was 45-fold higher by patients" age (CI 95%: 3.3-15.9: P = 0.001). When adjusted for patient age, sex and race, the risk was 6.4 fold ligher of having cancer if compared to the others (CI 95%: 49-84, P = 0.001). Melanoma was not found in HIV-infected. Conclusion With this study, we have demonstrated that HIV-infected patients have an increased risk of BCC and SCC. Preventive dermatologic management is pivotal in the care of immunosuppressed patients. These patients must undergo the dermatological examination annually and should receive extensive counseling regarding sun avoidance, use of sunscreens,and sun-protective clothing.

The role of mobile teledermoscopy in skin cancer triage and management during the COVID-19 pandemic.

The unprecedented onset of the COVID-19 crisis poses a significant challenge to all fields of medicine, including dermatology. Since the start of the coronavirus outbreak, a stark decline in new skin cancer diagnoses has been reported by countries worldwide. One of the greatest challenges during the pandemic has been the reduced access to face-to-face dermatologic evaluation and non-urgent procedures, such as biopsies or surgical excisions. Teledermatology is a well-integrated alternative when face-to-face dermatological assistance is not available. Teledermoscopy, an extension of teledermatology, comprises consulting dermoscopic images to improve the remote assessment of pigmented and non-pigmented lesions when direct visualisation of lesions is difficult. One of teledermoscopy's greatest strengths may be its utility as a triage and monitoring tool, which is critical in the early detection of skin cancer, as it can reduce the number of unnecessary referrals, wait times, and the cost of providing and receiving dermatological care. Mobile teledermoscopy may act as a communication tool between medical practitioners and patients. By using their smartphone (mobile phone) patients can monitor a suspicious skin lesion identified by their medical practitioner, or alternatively self-detect concerning lesions and forward valuable dermoscopic images for remote medical evaluation. Several mobile applications that allow users to photograph suspicious lesions with their smartphones and have them evaluated using artificial intelligence technology have recently emerged. With the growing popularity of mobile apps and consumer-involved healthcare, this will likely be a key component of skin cancer screening in the years to come. However, most of these applications apply artificial intelligence technology to assess clinical images rather than dermoscopic images, which may lead to lower diagnostic accuracy. Incorporating the direct-to-consumer mobile dermoscopy model in combination with mole-scanning artificial intelligence as a mobile app may be the future of skin cancer detection.