Noninvasive diagnostic techniques in the preoperative setting of Mohs micrographic surgery: A review of the literature.

Mohs micrographic surgery (MMS) is considered the gold standard treatment for skin cancers. Though the high cure rates it offers, MMS presents some disadvantages, as it is a relatively time-consuming procedure involving several professionals (physicians and technicians). A better definition of tumor margins in the preoperative setting with any optical noninvasive diagnostic method may reduce the numbers of MMS steps and the overall duration of the procedure. The present review was conducted and reported using validated search strategies from the following databases: PUBMED and Ovid MEDLINE. Our review describes the use of procedures such as dermoscopy, optical coherence tomography, reflectance confocal microscopy and fluorescent confocal microscopy to determine tumor extension in the preoperative setting of Mohs surgery for the treatment of skin cancers. Presurgical margin assessment with noninvasive diagnostic techniques seem to provide a benefit in the patients' management, especially for tumors located in critical areas with a high risk of recurrence. The use is limited to the high costs and limited availability of new technologies.

Fluorescence-advanced videodermatoscopy (FAV) for the differential diagnosis of suspicious facial lesions: A single-centre experience with pattern analysis and histopathological correlation.

BACKGROUND: Fluorescence-advanced videodermatoscopy (FAV) is a new non-invasive high-resolution skin imaging technique to assess pigmented lesions in conjunction with the clinical examination and dermatoscopy. OBJECTIVES: This is the first prospective study to identify morphologic descriptors and standardized terminology to examine facial pigmented lesions using FAV. The objectives were to identify FAV indicators, which can assist physicians in diagnosing suspicious flat facial pigmented lesions. METHODS: Consecutive equivocal pigmented lesions were retrospective analysed. Histopathological examination was performed for all the lesions. The main cytomorphological and cytoarchitectural FAV features were described and correlated with histopathological characteristics. RESULTS: From January to October 2020, 21 consecutive clinically suspected pigmented lesions in 20 patients were analysed using dermatoscopy and FAV and then surgically excised. Histopathological examination identified lentigo maligna (LM), lentigo maligna melanoma (LMM), solar lentigo (SL), flat seborrheic keratosis (SK) and pigmented actinic keratosis (PAK). Thirteen malignant melanocytic lesions were removed (11 LM, 2 LMM), two were diagnosed as PAK, and the remaining six pigmented lesions were SL-SKs. With FAV, large ovoid pleomorphic and dendritic cells arranged in the intrafollicular disposition, are typical of most malignant melanocytic lesions (12/13, 92.3%). No benign lesions displayed these features. In dermatoscopy, this folliculotropism corresponded to the presence of an annular-granular pattern with slate grey dots that were aggregated asymmetrically around follicular openings. CONCLUSIONS: FAV features can provide an improved diagnostic approach in the differential diagnosis of flat pigmented facial lesions.

Cutaneous immune-related adverse events and photodamaged skin in patients with metastatic melanoma: could nicotinamide be useful?

Cutaneous immune-related adverse events (irAEs) occur in more than one-third of patients treated with immune checkpoint inhibitors; they are often the first clinical manifestation, although they may occur months after initiation of therapy. We noticed that our patients usually have these cutaneous AEs on photodamaged skin. In fact, out of 19 patients being treated for metastatic melanoma, 8 (42%), all of whom had significant cutaneous actinic damage, developed cutaneous irAEs earlier and in a more serious form than those without such damage. Thus, we gave a high oral dose of nicotinamide (500 mg twice daily) to the patients with metastatic melanoma who had photodamaged skin, and continued this for the entire duration of the immunotherapy. The appearance of the first signs of cutaneous irAEs was 180 days after starting therapy in nicotinamide-treated patients, compared with 65 days for patients not treated with nicotinamide.

Atypical Spitz tumours: an epidemiological, clinical and dermoscopic multicentre study with 16 years of follow-up.

BACKGROUND: Atypical Spitz tumours (ASTs) are regarded as an intermediate category distinguished from prototypical Spitz naevus by presenting one or more atypical features and often by an uncertain malignant potential. Clinical and dermoscopic features may play a relevant role in the diagnostic approach. AIM: To evaluate the clinical and dermoscopic features of ASTs, and their evolution over time. METHODS: This was a descriptive, multicentre study of the clinical and dermoscopic characteristics of ASTs. Data on clinical and dermoscopic characteristics, histopathology, local extension, therapy and follow-up, lymph node staging, complete lymph node dissection, and outcome were collected from the databases of four Italian Dermatology Units for the period 2004-2021. RESULTS: The study population consisted of 99 patients (62 female, 37 male) with a histologically confirmed diagnosis of AST, including age at presentation ranged from 2 to 70 years (mean 28.1 years, median 24 years). Of the 99 patients, 29 (29.3%) underwent sentinel lymph node biopsy, which showed evidence of micrometastases in three cases (10.3%); all three patients underwent complete lymph node dissection with no evidence of further metastasis. Considering the whole study population, the clinical outcome was excellent, as all of the patients have no evidence of recurrence or distant metastasis. The follow-up period ranged from 6 to 216 months (mean 81.6 months, median 78 months). In addition, we collected data on the clinical and dermoscopic features of 26 lesions. The most frequent dermoscopic pattern observed was the multicomponent pattern (34.6%), followed by homogeneous (26.9%) and nonspecific (23.2%). In 66.7% of amelanotic ASTs, we observed glomerular (coiled) vessels uniformly distributed within the entire lesion, without asymmetry. CONCLUSION: The results of our study with a long follow-up show no recurrence or distant metastases, confirming the good clinical outcome, even in the case of sentinel lymph node positivity. From a diagnostic point of view, our series identified a typical dermoscopic picture for amelanotic ASTs, with a glomerular vascular pattern throughout the lesion in the absence of other dermoscopic parameters, making the correct diagnosis possible.

Clinical and dermoscopic polymorphisms in agminated Spitz nevi: Ugly presentation but benign behavior.

Agminated Spitz nevi are an uncommon entity, and their management is challenging due not only the young age of the patients but also the tumor's uncertain malignant potential and the variability in the dermoscopic and clinical presentation. We report a case of a 6-year-old boy with multiple agminated Spitz nevi on a café au lait macule with different atypical clinical patterns and dermoscopic features.

Towards a holographic approach to spherical aberration correction in scanning transmission electron microscopy.

Recent progress in phase modulation using nanofabricated electron holograms has demonstrated how the phase of an electron beam can be controlled. In this paper, we apply this concept to the correction of spherical aberration in a scanning transmission electron microscope and demonstrate an improvement in spatial resolution. Such a holographic approach to spherical aberration correction is advantageous for its simplicity and cost-effectiveness.