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A 59-year-old white woman presented with a 2-year history of a moderately painful nail-plate abnormality of the fifth toenail

Mohs micrographic surgery (MMS) is a good treatment option for epithelial neoplasms, especially when localized in areas where tissue conservation is crucial, such as the nail unit (NU). MMS is a method of radical excision offering high cure rates due to the margin control and functional preservation. Our aim is to provide a review on the use of MMS for the treatment of the most common nail tumours. We revised the current literature on the use of MMS to treat malignant neoplasms (Bowen's disease, squamous cell carcinoma, melanoma, basal cell carcinoma, keratoacanthoma, carcinoma cuniculatum) and benign neoplasms (onychomatricoma and glomus tumour). MMS represents a successful surgical option for nail tumours, firstly in terms of tissue conservation: the NU anatomy is complex and the preservation of the component structures is imperative for its functionality. Secondly, due to the surgical radicality, which is essential not only for the clearing of malignant tumours, but also for benign cases, in order to reduce recurrences. Although a conservative treatment of NU melanoma with MMS has been proposed, in our experience, the conservative approach with functional surgery is a good option for the treatment of non-invasive melanoma (in situ and Ia).

Breslow thickness (BT) is the most important histopathologic factor for primary melanoma staging. BT determines the margins for wide local excision whether sentinel lymph node biopsy should be performed and subsequent melanoma staging, and patient management. The correct determination of a 0.8-mm cutoff in melanoma is important for pathologists because discrepancies leading to a change in stage can have significant clinical implications, including incorrect and/or inappropriate prognostic information, investigation, management, and follow-up. Difficulties in BT determination are mostly represented by the presence of regression or melanoma associated with a pre-existing nevus. This study aimed at investigating a molecular parameter, namely microRNA (miRNA) expression, in reference to BT assessment. Melanoma cell proliferation is influenced by miRNA dysregulation. Indeed, some miRNAs sustain and induce proliferative signals or repress growth-suppressive pathways, thereby promoting melanoma carcinogenesis. To identify the miRNAs correlating with BT, we analyzed our global miRNA expression data of 20 thin melanomas and identified two potential candidates, miR-21-5p and miR-146a-5p. We assessed the expression of these two specific miRNAs in 90 archive formalin-fixed and paraffin-embedded samples of superficially spreading melanomas (SSMs) and 25 nodular melanomas from two independent cohorts and correlated the individual and combined miRNA expression with BT and other tumor characteristics. The individually normalized expression of miR-21-5p and miR-146a-5p showed a highly significant and linear correlation with BT in SSM, and their combined expression value was more strongly correlated (Pearson’s r = 0.799, 95% CI = 0.71–0.86) than their individual expressions. This correlation was not significant in nodular melanoma. In SSM, we observed that the combined miRNA expression above or below 1.5 was significantly associated with overall survival and successfully identified all patients with relapsing SSM. We concluded that the combined assessment of miR-21-5p and miR-146a-5p expression in superficially spreading melanoma, in association with BT measurement, could aid pathologists in SSM staging.

Acral lentiginous melanoma (ALM) is the most common type of malignant melanoma (MM) in Asians, Afro-Americans and Middle-Easterners. It represents 1.5-10% of all MM cases, being the most common histological type of MM arising on palms, soles and nail apparatus, which is more generically defined as acral MM. To date no risk factors have been officially established, however a history of trauma may be involved in the pathogenesis of acral MM. This shows heterogeneous clinical features and frequently presents with advanced stage and aggressive behavior, often as a result of misdiagnosis or delayed identification. Dermoscopy is helpful for an early diagnosis of ALM: the most characteristic dermoscopic patterns are the parallel ridge and the irregular diffuse pigmentation. On histopathology ALM displays a lentiginous growth pattern, with melanocytes arranged as solitary units along the basilar epidermis, without notable pagetoid growth in the early stage. Not all acral MMs present a lentiginous pattern: superficial spreading melanoma and nodular melanoma patterns are also possible. Novel studies investigating the biologic characteristics of acral MM reported variable results: the overall mutational rates ranged respectively between 8.5% and 23% for KIT, between 3.6% and 33.3% for BRAF and between 3% and 47% for NRAS in ALMs. Increasing attention has been recently given to other genes, such as telomerase reverse transcriptase, platelet-derived growth factor receptor alfa and cyclin D1. Larger molecular investigations urge to describe the molecular profile of acral MM, to allow the development of specific targeted therapies.

Background Skin biopsy is an important tool for various skin conditions. However, in the case of leg ulcers, some Authors still consider it highly risky and mandatory only in selected cases. Methods The aim of this study was to evaluate the rate of adverse events after leg ulcers biopsy in 866 consecutive patients referring to our Wound Care Unit in Bologna from January 2008 to December 2016. Two biopsies were performed (from the border and the centre) by the same dermatologist following a standardized structured protocol. Results A total of 329 males and 537 females (ratio of 1:1.6), mean age 72 years (range 50-97 years) underwent a skin biopsy. Up to 70% of all analyses revealed a vascular ulcer (614 patients; 70.9%) while other conditions (252 patients; 29.1%) included inflammatory dermatitis, vasculitis, ulcerated neoplasms, infective lesions, post-traumatic and pressure sores, erosive pustular, dermatitis and pyoderma gangrenosum. Adverse events occurred in 322 patients (38.43% of all biopsies), mostly a dull pain (320 patients, 37%) that resolved within some hours. Five patients with vasculitis (0.6%) experienced a worsening of the lesion and another five patients (0.6%) developed erysipelas. Only two patients, on double antithrombotic therapy (0.23%), had intraoperative bleeding. No allergic reactions were detected. Conclusions According to our experience, skin biopsy should be mandatory for non-healing wounds. It is safe and involves only a low rate of adverse events.

Spitzoid neoplasms may represent a difficult diagnosis in the practice of dermatopathology. We evaluated the concordance of the fluorescence in-situ hybridization (FISH) assay, histopathology, and dermoscopy in a group of adults and in a group of children with spitzoid neoplasms. The FISH assay, designed to detect the copy number of the RREB1 (6p25), MYB (6q23), and CCND1 (11q13) genes and of centromere 6 (Cep 6), was performed in a group of children and in a group of adults with a histopathologic diagnosis of spitzoid neoplasms. FISH data were compared with dermoscopy and histopathology. Fifteen spitzoid neoplasms were collected from 13 patients (five children and eight adults): nine lesions were histologically diagnosed as typical Spitz nevi; three lesions were melanomas and three were atypical Spitz nevi. The conventional FISH criteria were concordant with the clinical and histopathologic diagnosis of Spitz nevi in four adults and in three children. FISH criteria of the other neoplasms showed a concordance with the histopathologic diagnosis in three cases. Discordant results were obtained in five cases (two children, three adults). The FISH melanoma assay proved more reliable in spitzoid lesions found in adults than in children. This assay should be interpreted carefully in pediatric patients with Spitz nevi in the context of histological features as melanomas in the pediatric population may show distinct chromosomal aberrations.

The observation of a black-brown pigmentation of the nail is often alarming for the patient and for the clinician, as they are aware that it can be a possible clinical manifestation of melanoma of the nail apparatus. Luckily, however, nail melanoma is a much less frequent cause of brown-black nail color than other melanocytic and nonmelanocytic pigmentations, which include subungual hematoma, exogenous pigmentations, and melanonychia due to benign conditions. A correct clinical history and careful examination help the clinician to distinguish the different conditions and to decide the correct management of melanonychia both in children and in adults.