Nevus-associated Lentigo Maligna and Lentigo Maligna Melanoma, Clinicopathological Features

Nevus-associated lentigo maligna and lentigo maligna melanoma (NALMM) are rarely described in the literature and are considered an incidental finding. This study aimed to evaluate the frequency of NALMM and its clinicopathological features. A total of 201 histopathology reports were reviewed and among them 20% of the samples corresponded to NALMM, with females overrepresented in this group (p = 0.02). A significant association was also observed between NALMM with the presence of multiple nevi (p = 0.01), and dysplastic nevi (p = 0.04). Moreover, the risk of developing a second melanoma of nevus-associated type was 4.3 times higher in patients with NALMM. These results indicate that NALMM is more frequent than previously reported, suggesting that the associated nevus could interact or even act as a precursor for LM/LMM. Future studies with larger samples allied to techniques like confocal microscopy and molecular analysis are essential to determine this biological link between nevus and LM/LMM.

Targeted intradermal delivery of alpha-arbutin-loaded dissolving polymeric microneedles visualized by three-dimensional Orbitrap secondary ion mass spectrometry (3D OrbiSIMS)

Hyperpigmentation, a prevalent dermatological condition characterized by melanin overproduction, poses treatment challenges due to the hydrophilicity of alpha-arbutin, a widely utilized tyrosinase inhibitor. This study investigates the efficacy of dissolving microneedles (DMNs) in augmenting skin permeation for alpha-arbutin delivery to the targeted epidermal site. Porcine full-thickness skin was employed in a 24-hour Franz cell study, commencing with the assessment of commercial alpha-arbutin-containing products. Solid steel microneedles (CMNs) from Dermapen® were utilized as both pre- and post-treatment modalities to evaluate the influence of different applications on alpha-arbutin delivery. Additionally, alpha-arbutin-loaded polyvinylpyrrolidone-co-vinyl acetate (PVPVA) DMNs, containing 2 % w/w alpha-arbutin, were fabricated and examined for their permeation-enhancing capabilities. HPLC analysis and 3D Orbitrap Secondary Ion Mass Spectrometry (OrbiSIMS) were employed to quantify and visualize alpha-arbutin in various Franz cell components. Results indicate that alpha-arbutin permeation to the skin was restricted (less than 1 %) without microneedle application and significantly increased by 6-fold (4-5 %) with post-treatment CMNs and DMNs, but not with pre-treatment CMNs. Notably, DMNs exhibited a more sustainable and robust capacity than post-treatment CMNs. OrbiSIMS imaging analysis revealed that DMNs visually enhance skin permeation of alpha-arbutin by delivering the compound to the basal layer of the targeted skin location. Overall, this study underscores the potential of DMNs as a promising delivery system for promoting targeted intradermal delivery of alpha-arbutin, providing a comprehensive exploration of various methodologies to identify innovative and improved microneedle approaches for alpha-arbutin permeation.

Invasive cellular blue nevus in the cervical spine: A case report

INTRODUCTION

Cellular blue nevus is an uncommon neoplasm in the spine.

PATIENT CONCERNS

Here, we present a case of a 24 years old male with a 2 months history of numbness in the right upper limb and shoulder.

DIAGNOSIS

Cervical spine and subcutaneous tissue invasive cellular blue nevus.

INTERVENTIONS

The patient underwent C4 laminectomy and partial C3 and C5 laminectomy for total resection of the lesion. Histopathology revealed a nodular tumor with unclear boundaries, which was composed of heavily pigmented dendritic cells and more pigmented spindle cells.

OUTCOMES

There was no recurrence during 3 years follow-up.

CONCLUSION

Invasive cellular blue nevus of the spine can be wrongly diagnosed as spinal meningeal melanocytoma and meningeal melanoma due to its special cell behavior and rarity. Therefore, it is important to understand its pathological and clinical characteristics to avoid over-treatment.

Nevus lipomatosus superficialis: A series of six cases

Nevus lipomatosus still imposes diagnostic, categorization, and etiologic challenges. Even though an intradermal adipose tissue is a histopathologic prerequisite, the lesions are clinically divided into classic multiple forms and a solitary variant, which some consider a separate so-called lipofibroma clinicopathologic entity. This further complicates the true prevalence, classification and etiopathogenesis of nevus lipomatosus. Case reports and series studies have reflected either consistent or variable and sometimes conflicting clinicopathologic findings. A few have reported electron microscopic findings. Immunohistochemistry is lacking. We report two multiple and four solitary forms of nevus lipomatosus in six patients, highlighting their salient histopathologic features and immunohistochemical profile. Both forms showed intradermal groups of perivascular S100+ lipogenic and CD34+ mesenchymal cells intermixed with scattered CD1a+ and FXIIIa+ dendrocytes, CD3 lymphocytic and CD117 mast cells in a fibromyxoid milieu. Epidermal nevoid and comedonal follicular alterations, attenuated dermal connective tissue and adnexal structures were variably present in both forms. We compared our findings with seven series of studies reporting classic and solitary forms. Both forms showed similar histopathologic findings, comparable clinicopathologic features, predominantly pelvic, and shoulder girdle distribution patterns in bimodal age onsets. Even though some lipomatous skin lesions clinically and histopathologically overlap with nevus lipomatosus, certain findings are helpful distinguishing features. Small intradermal islands of lipocytic fibroplasia have characteristic perivascular milieu that may function as a niche of preadipose CD34 mesenchymal stem cells. They are most likely represented in the dermis of the pelvic and shoulder areas in certain individuals prone to maintain these embryonic reservoirs, which are clinically manifested at different ages. Some may have unifocal or multifocal residues reflecting multiple and solitary forms.

Cutaneous melanocytic tumor with CRTC1::TRIM11 fusion: a case report

BACKGROUND

Cutaneous Melanocytic Tumor with CRTC1::TRIM11 Fusion (CMTCT) represents a novel and rare entity in the realm of dermatological oncology, characterized by distinct melanocytic differentiation. This particular tumor type has yet to be officially recognized by the World Health Organization (WHO). CMTCT is generally perceived as a tumor with a relatively indolent nature; however, it is not devoid of metastatic potential. Therefore, ensuring complete surgical excision of the tumor, coupled with rigorous long-term follow-up, is paramount for patient management. In this context, we report the case of an 18-year-old female patient who presented with a dull red nodule on her left leg. Initial surgical intervention led to a pathological diagnosis of CMTCT, but it was determined that the tumor had not been fully excised. Consequently, a second surgical procedure was undertaken to achieve complete removal of the tumor. During a follow-up period of six months post-surgery, the patient showed no signs of local recurrence or metastasis, indicating a successful outcome.

CASE PRESENTATION

An 18-year-old female patient noticed a dull red nodule on her left leg three years ago, which exhibited slow growth over time. She underwent a subcutaneous tumor resection. Histological examination under high-power magnification revealed that the neoplasm consisted of epithelioid cells arranged in nests, fascicles, bundles, or sheets. The tumor cells had round or ovoid nuclei with prominent nucleoli and visible mitotic figures. Notably, areas resembling nevus cell clusters were observed. Immunohistochemical analysis confirmed melanocytic differentiation. Next-generation sequencing (NGS) identified a CRTC1::TRIM11 fusion, and fluorescence in situ hybridization (FISH) for CRTC1 confirmed rearrangement. Consequently, a diagnosis of cutaneous melanocytic tumor with CRTC1::TRIM11 fusion was established.

CONCLUSIONS

CMTCT is a rare tumor characterized by melanocytic differentiation. In this case, the tumor predominantly comprised epithelioid cells with localized nevus cell clusters. The expression of melanocyte markers could easily lead to a misdiagnosis as cutaneous melanoma. However, several distinguishing features were noted: the tumor was not connected to the epidermis, exhibited low cellular heterogeneity and proliferation index, and showed minimal cellular atypia. Additionally, tests for EWSR1 rearrangement (FISH) and BRAF V600E mutation (PCR-ARMS) were negative.This case underscores the importance of a comprehensive diagnostic approach when clinical, microscopic, immunohistochemical, and molecular findings do not align. The presence of nevus cell clusters morphology in the tumor cells enhances our understanding of this disease's histological spectrum and aids in avoiding misdiagnosis or missed diagnosis.

Iris melanoma: Review of clinical features, risks, management, and outcomes

Primary uveal melanoma is rare and affects approximately 8,000 persons per year worldwide. This malignancy can involve the iris, ciliary body, and choroid. Of these three structures, the iris is the least commonly affected site, representing only 4% of all uveal melanomas. Iris melanoma can arise from iris melanocytic nevus, iris melanocytosis, or de novo. In a longitudinal study of 1,611 patients with iris nevus, transformation into melanoma, using Kaplan-Meier estimates, was found in 2.6% by five years and in 4.1% by 10 years. The factors that predicted growth of iris melanocytic nevus into melanoma are denoted by a letter (ABCDEF) guide: A for age ≤40 years old at presentation (hazard ratio [HR] = 3, P = .01), B for blood (hyphema) (HR = 9, P < .0004), C for clock hour of tumor inferiorly (tumor location) (HR = 9, P = .03), D for diffuse flat tumor configuration (HR = 14, P = .02), E for ectropion uveae (HR = 4, P = .002), and F for feathery ill-defined margins (HR = 3, P = .02). At diagnosis, iris melanoma has a mean cross-sectional diameter of 5.5 mm and thickness of 2.1 mm, often with tumor seeding (28%) and secondary glaucoma (35%). We provide a comprehensive review of iris nevus and melanoma to explore relevant demographic and clinical data, risk factors for tumor growth, management, and prognosis, with the hope that clinicians will be more comfortable in understanding this rare malignant condition.

A Comparative Demographic Study of Atypical Spitz Nevi and Malignant Melanoma

Spitz tumors are a subset of melanocytic neoplasms characterized by epithelioid or spindled melanocytes(1). The benign nature of the "Spitz nevus" has since been clarified, but the debate regarding Spitzoidtumors (STs) is still ongoing. Spitzoid tumors encompass a wide spectrum of cutaneous lesions ranging from benign Spitz nevus (SN) to Spitzoid melanoma (SM), the latter displaying capacity for widespread metastasis and a potentially lethal outcome (2). The term atypical Spitz tumors (ASTs) refers to melanocytic tumors exhibiting the morphological features of SN, as well as some features associated with malignancy, but not sufficient to classify them as SMs. Currently, histopathology is the gold standard for the diagnosis of STs and cutaneous MM. However, the differential diagnosis between benign and malignant melanocytic lesions with spitzoid features remains challenging (3-6). In order to facilitate the work of clinicians and pathologists, we attempted a comparative clinical and demographic study comparing ASTs and MMs of patients referred to two Italian institutes. Patient data were obtained from two different Italian dermatological centers (Melanoma Registry of the Instituto Dermopaticodell'Immacolata IDI-IRCCS Rome, Lazio and the Skin Cancer Unit of Dermatology, Hospital Sant'Orsola-Malpighi, University of Bologna), from January 2007 to December 2017. Histological reports presenting pre-operative queries of both "atypical Spitz nevi" or "malignant melanoma" and a final diagnosis confirming one of the queries were included in the study. The chi-square test or Mann-Whitney U-test were applied to analyze differences between the groups for categorical variables such as sex, diagnosis, and continuous variables (age). The "anatomic site" variable was classified into three categories as follows: the limbs, trunk, and head/neck. A multivariate binary logistic model was used to investigate if the anatomic site was an independent predictor of MM. Age and sex were considered confounding factors. A total of 504 patients (51.8% men; 48.2% women) met the inclusion study criteria (mean age 52 years, SD = 22.8) (Table 1). 373 were cases of MM and 131 were cases of AST. Mean age of MM cases and AST were 61.2 years old (SD = 17.6) and 25.8 years old (SD = 13.8), respectively. Subjects with MM were predominantly men (58.2% versus 33.6%) (P<0.0001) and older (median age 62 years versus 25 years) (P=0.0001) than subjects with AST. The most frequent anatomic site for MM was the trunk (39.7 %), while the lower limb was the most frequent anatomic site for AST (48.1 %) (P<0.0001). Table 2 shows the multivariable analysis used to assess if anatomic site was an independent predictor of cutaneous melanoma. Multivariate analysis confirmed an increased risk for MM in comparison with AST for both localization on the trunk (OR:2.78; 95 %CI: 1.74-4.45) (P<0.0001) and head/neck (OR:3.20; 95% CI: 1.60-6.38) (P=0.0001). After introducing age (model 1, OR: 2.11; 95% CI: 1.08-4.12) (P=0.003) and sex into the model, the only anatomic site that remained statistically significant was the trunk (model 2, OR: 2.03; 95% CI: 1.0.3-3.99) (P=0.04). The results show that if the lesion was located on the trunk, the probability of being a MM was two times higher than that of AST, independent of sex, age, or center. After stratifying for sex, the effect was stronger for women (OR: 2.72; 95% CI: 1.14-6.50). After stratifying for age, the effect was stronger for younger subjects (<40 years) (OR: 2. 59; 95% CI: 1.20-5.60) (P=0.02). In this study, we focused on the clinical-epidemiological data in an attempt to improve the identification of nodular melanocytic lesions by providing clinicians with further information in order to reduce the rate of misdiagnosis and assist in providing critical clinical information to surgeons and pathologists. Consistently with the literature, ASTs were mainly found in young-adult patients (mean age was 25.8 years), in the female sex (66.4%), and were typically located on the lower limbs (48.1%) (3,7-10). MM were found to be slightly more common in male patients (58.2%) in the overall patient group; the mean age at the time of the diagnosis was 61.2 years old, and the majority of lesions were located on the trunk (39.7%). These data were similar to those reported by other authors (11-13). ASTs cases were mainly women and younger than MM cases, and were typically located on the lower limbs (Figure 3 and Figure 4). Nodules located on the trunk resulted in a two times greater risk of MM in comparison with AST. In summary, distinguishing ASTs from MMs is often challenging, and histopathology remains the diagnostic gold standard for melanocytic neoplasms, but a specific clinical framework may help surgeons, pathologists, and clinicians to correctly diagnose and manage these lesions in children and adults.

Generation of a Melanoma and Nevus Data Set From Unstandardized Clinical Photographs on the Internet

Importance

Artificial intelligence (AI) training for diagnosing dermatologic images requires large amounts of clean data. Dermatologic images have different compositions, and many are inaccessible due to privacy concerns, which hinder the development of AI.

Objective

To build a training data set for discriminative and generative AI from unstandardized internet images of melanoma and nevus.

Design, Setting, and Participants

In this diagnostic study, a total of 5619 (CAN5600 data set) and 2006 (CAN2000 data set; a manually revised subset of CAN5600) cropped lesion images of either melanoma or nevus were semiautomatically annotated from approximately 500 000 photographs on the internet using convolutional neural networks (CNNs), region-based CNNs, and large mask inpainting. For unsupervised pretraining, 132 673 possible lesions (LESION130k data set) were also created with diversity by collecting images from 18 482 websites in approximately 80 countries. A total of 5000 synthetic images (GAN5000 data set) were generated using the generative adversarial network (StyleGAN2-ADA; training, CAN2000 data set; pretraining, LESION130k data set).

Main Outcomes and Measures

The area under the receiver operating characteristic curve (AUROC) for determining malignant neoplasms was analyzed. In each test, 1 of the 7 preexisting public data sets (total of 2312 images; including Edinburgh, an SNU subset, Asan test, Waterloo, 7-point criteria evaluation, PAD-UFES-20, and MED-NODE) was used as the test data set. Subsequently, a comparative study was conducted between the performance of the EfficientNet Lite0 CNN on the proposed data set and that trained on the remaining 6 preexisting data sets.

Results

The EfficientNet Lite0 CNN trained on the annotated or synthetic images achieved higher or equivalent mean (SD) AUROCs to the EfficientNet Lite0 trained using the pathologically confirmed public data sets, including CAN5600 (0.874 [0.042]; P = .02), CAN2000 (0.848 [0.027]; P = .08), and GAN5000 (0.838 [0.040]; P = .31 [Wilcoxon signed rank test]) and the preexisting data sets combined (0.809 [0.063]) by the benefits of increased size of the training data set.

Conclusions and Relevance

The synthetic data set in this diagnostic study was created using various AI technologies from internet images. A neural network trained on the created data set (CAN5600) performed better than the same network trained on preexisting data sets combined. Both the annotated (CAN5600 and LESION130k) and synthetic (GAN5000) data sets could be shared for AI training and consensus between physicians.

Optical Density Ratio of Subretinal Fluid in Choroidal Melanomas Versus Choroidal Naevi Assessed by Optical Coherence Tomography

Purpose

The purpose of this study was to determine whether optical density ratio (ODR) of subretinal fluid (SRF) on optical coherence tomography (OCT) differs between choroidal naevi and melanomas.

Methods

One hundred ninety-nine patients (one eye per patient) presenting choroidal melanoma or choroidal naevus with SRF on OCT, evaluated between February and June 2019, were retrospectively included. Other retinal conditions, opaque media, and low-quality OCT were excluded. Mean pixel intensity of SRF (range = 0-255) was quantified using a semi-automated procedure by a masked observer on standard horizontal OCT sections. Mean vitreous intensity served as the reference for ODR.

Results

One hundred twenty-eight patients with choroidal melanoma and 71 patients with choroidal naevus were included in this study. ODR (mean ± SD) was higher in melanomas (181 ± 64) than in naevi (78 ± 48, P < 0.0001). ODR was correlated to lesion thickness (P < 0.0001, r = 0.27), largest basal diameter (P = 0.028, r = 0.16) and, among naevi, to the number of risk factors for growth into melanoma (P = 0.032, r = 0.22). Among 110 patients with naevi or melanoma who underwent fluorescein angiography, ODR was 120.7 ± 550.1 in eyes presenting angiographic pinpoints versus 14.19 ± 26.0 in eyes that did not (P = 0.06). Fourteen eyes with naevi that transformed into melanoma over 3 years had a mean baseline ODR of 94.7 ± 243.5 compared to 4.01 ± 9.74 in 28 matched naevi eyes of similar size that did not transform (P = 0.027).

Conclusions

SRF ODR is higher in choroidal melanoma compared to choroidal naevi. This OCT-derived imaging marker is also higher in choroidal naevi with the potential to transform into melanoma, compared to stationary naevi.

Schimmelpenning-Feuerstein-Mims syndrome induced by HRAS Gly12Ser somatic mosaic mutation: Case report and literature review

Schimmelpenning-Feuerstein-Mims syndrome (SFMS), an epidermal nevus disease, features skin lesions including craniofacial nevus sebaceous and extracutaneous anomalies (e.g. brain, eye, and bone). Recent genetic studies implicate HRAS, KRAS, and NRAS genes in somatic mutations. Our case, a 48-year-old man, presented with nevus sebaceous on the scalp; pigmented skin lesions on the right side of his neck, back, and chest along the Blaschko lines; a history of epilepsy; and mild intellectual disability. Accordingly, SFMS was suspected. DNA analysis of nevus sebaceous skin and peripheral blood leukocytes showed a pathogenic HRAS variant NM_005343.4:c.34G > A p.(Gly12Ser) in biopsy specimens from different skin layers but not blood, indicating somatic mosaic mutation. Until now, the HRAS p.(Gly12Ser) mutation has been reported in somatic RASopathies but not SFMS. The authors report this mutation in a case of SFMS, review another 15 cases of SFMS, and discuss HRAS c.34G > A p.(Gly12Ser) somatic mutations. RAS mutations of somatic RASopathies share activating hotspot mutations found in cancers, and produce different phenotypes depending on the developmental stage at which the somatic mutations occur.

Population-based incidence of intraocular tumours in Olmsted County, Minnesota

BACKGROUND/AIMS

To determine population-based incidence of intraocular tumours in Olmsted County, Minnesota.

METHODS

Record review of the Rochester Epidemiology Project medical record linkage system from 1 January 2006 to 31 December 2015 for patient demographics, tumour type by clinical diagnosis and presence or absence of confirmation by histopathology. The incidence rate of any intraocular tumour and of each tumour type was calculated per million person-years. Poisson regression analysis was used to analyse changes in incidence over time.

RESULTS

There were 948 patients diagnosed with intraocular tumours resulting in an age-adjusted and sex-adjusted incidence rate of 727.5 per million (95% CI: 680.8 to 774.2, p<0.05). Most tumours were benign (953, 98%). Of the benign lesions, melanocytic lesions were the majority (942, 97%), with adjusted incidence rates of 646.9 (95% CI: 602.8 to 691.1) for choroidal nevus and 55.8 (95% CI: 43.2 to 64.8) for iris nevus. Malignant lesions were rare (16, 2%) with 13 cases of choroidal melanoma and 1 case each of iris melanoma, retinal leukaemic infiltration and metastasis. The adjusted incidence rate for choroidal melanoma was 7.1 (95% CI: 2.5 to 11.8).

CONCLUSION

In a population-based setting, most intraocular tumours are benign and melanocytic. Although malignant lesions are less common, it is important to remain vigilant with appropriate monitoring given the potential for vision loss and life-threatening malignancy.

NITROSOGENESIS, ANTIDEPRESSANTS AND THE SERTRALIN INDUCED NEVUS ASSOCIATED CUTANEOUS MELANOMA: THE NDMA/ NNK (NDSRIS) CONTAMINATION AS MOST POTENT MELANOMA INDUCTORS: ALEA IACTA EST

The purposeful oblivion of the objective truth, the disregard of scientific reality, the denial of the contributions and successes of surrounding researchers, the substitution of priorities in clinical routine and the unwillingness to reason in the right direction often lead to disastrous consequences in the field of public health. Controlled projects almost never lead to a significant contribution or breakthrough in medicine that will be remembered by future generations. Another illustrative example in this regard is the link shared above to the saga of the worldwide cancer pandemic and its possible real cause: the contamination of drugs with nitrosamines/NDSRIs. The carcinogenic action of nitrosamines in rats under experimental conditions was demonstrated as early as the early 1960s (1954) by Barnes and Magee. The series of subsequent experiments in their numerous research studies was strongly indicative of a pathogenetic role of nitrosamines / dimethylnitrosamine / in the development of liver cancer and kidney cancer. Starting from the fact that contact with nitrosamines is of primary importance for the development of tumours in animals, there is practically no circumstance that would lead us to believe that the intake of the same mutagens in man would have a different carcinogenic effect from that already known to us (as was found under experimental conditions as early as 1954, but in animals). On the contrary, to this day the incidence of cancer is increasing every year and, according to global statistics, it is projected to increase by nearly 50% or 18 million new cases by 2040. The intake of (un)identified nitrosamines found in drugs as contaminants is increasing analogously to the shared breakneck cancer incidence. In addition to the number of identified carcinogens or NDSRIs, the number of affected drug classes is also progressively growing and in mid-2023 this number amounts to over 250 drugs according to the official data of the FDA bulletin of 08.04.2023. In practice, the population/patients have been in a continuous, still ongoing, multicentric prospective study since 1954. The parameters of the ˝experiment˝ are probably pre-set, crystallizing gradually over time and imposed forcefully in the form of hypnotic suggestions and directives by regulators. Encouragingly , the results of the prospective study are also available, are not one-sided and have been published in dozens of international journals as well as in part in the well-known Cancer Journal of the clinicians / Impact factor 254,7. The bad news is that in most of these observations and results, there is no correlation of what is shared between, say, 1) mandatory alternative-free intake of mutagen-contaminated drugs and 2) the breakneck development of heterogeneous cancers/including melanomas, and the scientific vision of the studies is currently rather one-sided. Cancer incidence is skyrocketing (according to Globocan/Cancer Journal for the Clinicians), and not a single worldwide study has commented on its potential link to actual contamination of the most commonly used drugs worldwide with nitrosamines/NDSRIs. For the past 5 years, the team of the Bulgarian Society of Dermatological Surgery has been committed to formalizing the final results of these prospective nationwide observational studies and providing full transparency on the relationship between the intake of actual/potential nitrosamine-contaminated drugs and the development of skin cancer. Over 95% of newly reported skin cancers during this period (2016-2023) were associated with prior intake of drugs listed in the 2023 FDA as potentially nitrosamine/NDSRIs contaminated or carcinogens. Melanoma is one of the most significant patterns of tumor arising after contact of the human body with nitrosamines. Whether the drugs affected by the contamination are from the group of sartans, beta blockers, hydrochlorothiazide, calcium antagonists, ACE inhibitors or antidepressants- the ultimate side effect remains the same and is known to the scientific community as or by the frightening and loud name : melanoma. We report the occurrence of another case of nevus associated cutaneous melanoma and multiple dysplastic nevi after taking the antidepressant Sertraline. A drug declared according to the official FDA bulletin of 08.04.2023 as potentially contaminated with class 2 nitrosamines/ NDSRIs: having similar to completely identical carcinogenic potency as that of NDMA and NNK. Or reciprocal to that in valsartan, irbesartan, olmesartan, repeatedly described already as possible melanoma inducers. According to the literature search, this is also the first case in the world of Sertraline-induced nevus associated cutaneous melanoma, and we share the view/ thesis that the real inducer of the tumor is in fact the impurities in the medication in the form of contaminants or nitrosamines: the so-called NDSRIs. The nitrosogenesis of skin cancer is a more than significant concept that has been cleverly concealed by the scientific community until recently. The reason for this concealment could be sought in the paramount importance or central role that the nitrosogenesis occupies at the base of the "pyramid" guaranteeing billions of dollars of monthly revenue to the regulators of globalism.

Differences in nomenclature usage and preference among dermatopathologists for "dysplastic" nevi: A national survey

BACKGROUND

Ongoing controversy exists regarding terminology used to describe atypical melanocytic nevi. Efforts to standardize nomenclature, including the 1992 NIH consensus conference, have been largely unsuccessful. Significant advances have revealed an increasingly detailed genetic picture of melanocytic neoplasms, including strong evidence for the existence of those with "intermediate" behavior.

METHODS

We sent an electronic survey to dermatopathologists (n = 846) to assess trends in nomenclature usage and attitudes toward developing new consensus nomenclature for atypical melanocytic nevi.

RESULTS

There were 229 complete responses (27.1% response rate). The most used/preferred nomenclature was "dysplastic nevus" (43%/39%, respectively), followed by the NIH-recommended terminology (28%/26%). Three-tier grading systems were most heavily used/preferred (79%/63%). Dermatopathologists based in New England were most likely to use the NIH terminology; on the other hand, "dysplastic nevus" or "other" were most used elsewhere (p = 0.029). Most (76%) expressed at least "moderate" enthusiasm for developing consensus nomenclature, with 47% "very" or "extremely" enthusiastic.

CONCLUSION

Little has changed with the wide variation in terminology for atypical melanocytic nevi. There continues to be no one dominant terminology in use. However, there is enthusiasm for standardization. A new attempt at updated consensus nomenclature may be fruitful.

[A historical case of fronto-orbital-calvarial nevus]

We report the case of a 22-year-old female patient, with no particular previous history, who had nevus progressively increasing in volume since birth. Physical examination revealed a huge bluish-grey mass in the left fronto-temporal-parietal region, extending beyond the midline, infiltrating the palpebral region with orbital extension and blindness in the left eye (A). Another isolated nevus was found in the occipital region, which measured 5cm along its longer axis. Craniofacial CT scan with IV contrast showed nevus extension into the left intraorbital region and infiltration of the scalp opposite the nevus, without involvement of the brain parenchyma. A 3-stage surgical procedure was performed, in the first stage two expanders were placed in the healthy occipital and contralateral parietal region. In the second stage, the entire parieto-temporo-occipital component was removed, the frontal component was reduced and the scalp, which had gained enough elasticity thanks to the expanders, was reconstructed using transposition flaps (B). The third stage consisted of resection of the remaining upper fronto-palpebral component and part of the orbital component with repair by total skin graft to cover any loss of substance (C). The result obtained was extraordinary and the patient was so happy to be able to live a normal life.

Deficient mismatch repair is detected in large-to-giant congenital melanocytic naevi: providing new insight into aetiology and diagnosis

BACKGROUND

The aetiologies of large-to-giant congenital melanocytic naevi (LGCMN) remain ambiguous. A previous study discovered signatures associated with deficient mismatch repair (dMMR) in patients with LGCMN. However, a screening diagnostic immunohistochemistry (IHC) panel of dMMR in patients with LGCMN has not been performed to date.

OBJECTIVES

To identify the MMR status and aetiologies of LGCMN.

METHODS

A total of 110 patients with CMN, including 30 giant CMN, 30 large CMN, 30 medium CMN and 20 small CMN, underwent diagnostic IHC (for MSH6, MSH2, PMS2 and MLH1) screening of dMMR. The control group comprised normal skin samples from 20 healthy people. MMR proteins with little effect (MSH3 and PMS1) on the MMR system were stained in all samples. The surgical procedures conducted on each patient were noted because they might alter the behaviour of CMN and confound the results. Binary logistic regression analyses were performed between the phenotypic data and MMR status to identify associations. Whole-exome sequencing was performed on the main naevi, satellite naevi and normal skin tissues of four patients to detect variants. Mutational signature analyses were conducted to explore the aetiologies of LGCMN.

RESULTS

dMMR was detected in 37% (11 of 30) of giant, 23% (7 of 30) of large and 7% (2 of 30) of medium CMNs, but were not identified in small CMNs or normal skin tissues. Moreover, multiple LGCMNs had a much higher dMMR rate than did single LGCMNs. The regression analyses showed that MMR status was significantly associated with CMN size and the presence of satellites, but was not correlated with age, sex, location, satellite diversity or tissue expansion. Notably, the pattern of protein loss in LGCMN mainly consisted of PMS2 loss. Mutational signature analyses detected dMMR-related signatures in patients with LGCMN. Additionally, rare deleterious germline mutations in DNA repair genes were detected in LGCMN, mainly in MSH6, ATM, RAD50, BRCA1 and ERCC8. These germline mutations were single-patient variants with unknown significance.

CONCLUSIONS

dMMR is one of the aetiologies underlying LGCMN, particularly in patients with giant main lesions and multiple satellite lesions. Further studies are necessary to investigate the role of the DNA repair system, particularly MMR, in LGCMN.

Computer Aided Diagnosis of Melanoma Using Deep Neural Networks and Game Theory: Application on Dermoscopic Images of Skin Lesions

Early detection of melanoma remains a daily challenge due to the increasing number of cases and the lack of dermatologists. Thus, AI-assisted diagnosis is considered as a possible solution for this issue. Despite the great advances brought by deep learning and especially convolutional neural networks (CNNs), computer-aided diagnosis (CAD) systems are still not used in clinical practice. This may be explained by the dermatologist's fear of being misled by a false negative and the assimilation of CNNs to a "black box", making their decision process difficult to understand by a non-expert. Decision theory, especially game theory, is a potential solution as it focuses on identifying the best decision option that maximizes the decision-maker's expected utility. This study presents a new framework for automated melanoma diagnosis. Pursuing the goal of improving the performance of existing systems, our approach also attempts to bring more transparency in the decision process. The proposed framework includes a multi-class CNN and six binary CNNs assimilated to players. The players' strategies is to first cluster the pigmented lesions (melanoma, nevus, and benign keratosis), using the introduced method of evaluating the confidence of the predictions, into confidence level (confident, medium, uncertain). Then, a subset of players has the strategy to refine the diagnosis for difficult lesions with medium and uncertain prediction. We used EfficientNetB5 as the backbone of our networks and evaluated our approach on the public ISIC dataset consisting of 8917 lesions: melanoma (1113), nevi (6705) and benign keratosis (1099). The proposed framework achieved an area under the receiver operating curve (AUROC) of 0.93 for melanoma, 0.96 for nevus and 0.97 for benign keratosis. Furthermore, our approach outperformed existing methods in this task, improving the balanced accuracy (BACC) of the best compared method from 77% to 86%. These results suggest that our framework provides an effective and explainable decision-making strategy. This approach could help dermatologists in their clinical practice for patients with atypical and difficult-to-diagnose pigmented lesions. We also believe that our system could serve as a didactic tool for less experienced dermatologists.

Inflammatory linear verrucous epidermal nevus (ILVEN) encompasses a spectrum of inflammatory mosaic disorders

BACKGROUND

Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disease characterized by pruritic erythematous scaly plaques distributed along the lines of Blaschko. Two cases of ILVEN with CARD14 mutations and one case with a GJA1 mutation have been previously reported.

OBJECTIVE

To elucidate the genetic cause of a cohort of patients diagnosed based on clinical and histopathological evaluation with ILVEN.

METHODS

We recruited patients diagnosed with ILVEN based on clinical and histopathological criteria. Exome sequencing of affected skin with or without blood/saliva was performed and germline and somatic pathogenic variants were identified.

RESULTS

Five patients were enrolled. All had skin lesions from birth or early childhood. Two patients developed psoriasis vulgaris after the diagnosis of ILVEN. The first had a germline heterozygous CARD14 mutation and a post-zygotic hotspot mutation in KRT10. The histopathologic evaluation did not show epidermolytic hyperkeratosis. The second had a post-zygotic hotspot mutation in HRAS. Her ILVEN became itchy once psoriasis developed. One patient was re-diagnosed with linear porokeratosis based on a germline mutation in PMVK and a post-zygotic second-hit mutation. Two patients were re-diagnosed with congenital hemidysplasia with ichthyosiform nevus and limb defect nevus based on germline NSDHL mutations.

CONCLUSION

ILVEN is a clinical descriptor for a heterogenous group of mosaic inflammatory disorders. Genetic analysis has the potential to more precisely categorize ILVEN and permits pathogenesis-directed therapies in some cases.

Pigmented Corneal Mass in a 59-Year-Old Man With Cutaneous Melanoma

A 59-year-old man with history of cutaneous melanoma of the trunk was referred for evaluation of a pigmented angle lesion in the right eye located in the cornea without extension past the Schwalbe line. It did not involve other angle structures such as the trabecular meshwork or scleral spur. What would you do next?

Malignant transformation of nevus sebaceous to basal-cell carcinoma: Case series, literature review, and management algorithm

Nevus sebaceous (NS) is a common congenital hamartoma of the skin composed predominantly of sebaceous glands. Although most NS are benign skin tumors, malignant transformations have been reported. There is still controversy about the lifetime risk of malignant degeneration and precise surgical criteria. This study reports cases of malignant degeneration and suggests a surgical treatment algorithm. The medical records of patients with basal-cell carcinoma (BCC) arising from NS between January 2001 and January 2021 were retrospectively reviewed. Patient demographics including lesion location, and tumor size were investigated. The symptoms, histological findings before and after excision, complications, and recurrence during 2-year follow-up periods were investigated. Ten patients were identified with BCC arising from NS lesions. All patients were female and the mean age was 52.11 years. All patients complained of sudden morphological changes, the most common type being rapid color changes. Two cases had histological findings that showed a miss-match between punch biopsy and excisional biopsy results. No recurrence was detected 2 years after surgeries in any patients. Cases after third stage, especially in over 40 years who report morphologic changes, should undergo total surgical excision as the first approach, with strong suspicion of malignant degeneration.

Clinical Reasoning: A 67-Year-Old Woman With Abdominal Pain, Constipation, and Urinary Retention

Meningeal melanocytomas are extremely rare, pigmented tumors of the CNS. They generally carry a favorable prognosis, although recurrence and transformation into the more aggressive malignant melanoma have been reported. We present a case of a patient who reported constipation and abdominal pain around the umbilicus, which progressed into cord compression with lower extremity weakness and gait instability. Spinal MRI revealed a tumor at the level of T11, and she underwent gross total resection of the mass. Pathology demonstrated a meningeal melanocytoma with intermediate features. She received postoperative radiation therapy and had stable disease for 3 years, at which time she developed new weakness and drop metastases. This case represents a rare presentation of a rare disease, in which a spinal cord tumor presented with constipation and abdominal distress. Intradural extramedullary tumors of the thoracic spine are most commonly nerve sheath tumors or meningiomas, but rare entities such as melanocytomas can present in this location; even more rarely, these tumors can have an aggressive course with delayed recurrence.

Making a mouse out of a molehill: how precision modeling repurposes drugs for congenital giant nevi

Patients with congenital giant nevi (CGN), which can compromise quality of life and progress to melanoma, have limited treatment options. Choi et al. have demonstrated that topical application of a proinflammatory hapten for alopecia treatment [squaric acid dibutylester (SADBE)] caused nevus regression and prevented melanoma in an Nras mouse CGN model. Their results demonstrate the promise of repurposing drugs through precision modeling.

Genomic comparison of malignant melanoma and atypical Spitz tumor in the pediatric population

BACKGROUND/OBJECTIVES

The diagnostic distinction between atypical Spitz tumor (AST) and malignant melanoma (MM) in pediatric tumors is challenging. Molecular tests are increasingly used to characterize these neoplasms; however, limited studies are available in pediatric patients. This study aimed to provide a genomic comparison of pediatric MM and AST in the context of comprehensive clinical annotation.

METHODS

Pediatric patients diagnosed with MM (n=11) and AST (n=12) were compared to a cohort of 693 adult melanoma patients. DNA next-generation sequencing assessed kinase gene fusions, tumor mutational burden, sequence variants, copy number alterations, structural variants, microsatellite instability, and mutational signatures.

RESULTS

Seven AST cases and eight MM cases were successfully sequenced. Kinase gene fusions were identified in both the MM and AST cohorts (NTRK1, ROS1, and MET). MM cases had TERT, BRAF, and CDKN2A alterations, which were not identified in the AST cohort. Tumor mutational burden (TMB) analysis showed pediatric ASTs had an average of 2.82 mutations/Mb, pediatric MM had an average of 5.7 mutations/Mb, and adult MM cases averaged 18.8 mut/Mb. One pediatric MM case had an elevated TMB of 15 mutations/Mb and a UV mutational signature.

CONCLUSIONS

These data expand our understanding of pediatric malignant melanoma. The differences between the molecular signatures for AST and MM are not statistically significant, and histopathology remains the gold standard for the diagnosis of pediatric AST and MM at this time. With more data, molecular studies may provide additional support for diagnosis and targeted therapeutics.

Tetraspanin CD9 Expression Predicts Sentinel Node Status in Patients with Cutaneous Melanoma

The tetraspanin CD9 is considered a metastasis suppressor in many cancers, however its role is highly debated. Currently, little is known about CD9 prognostic value in cutaneous melanoma. Our aim was to analyse CD9 expression in melanocytic nevi and primary cutaneous melanomas through immunohistochemistry and immunofluorescence approaches to determine its correlation with invasiveness and metastatic potential. CD9 displayed homogeneous staining in all melanocytic nevi. In contrast, it showed a complete loss of reactivity in all thin melanomas. Interestingly, CD9 was re-expressed in 46% of intermediate and thick melanomas in small tumor clusters predominantly located at sites of invasion near or inside the blood or lymphatic vessels. The most notable finding is that all CD9 stained melanomas presented sentinel node positivity. Additionally, a direct association between CD9 expression and presence of distant metastasis was reported. Finally, we confirm that CD9 expression is consistent with an early protective role against tumorigenesis, however, our data endorse in melanoma a specific function of CD9 in vascular dissemination during late tumor progression. The presence of CD9 hotspots could be essential for melanoma cell invasion in lymphatic and endothelial vessels. CD9 could be a valid prognostic factor for lymph node metastasis risk.

Clinical profile of melanocytic lesions of the ocular surface in a Hispanic population

PURPOSE

To determine the prevalence, clinical characteristics, and demographic factors of melanocytic lesions of the ocular surface, such as racial melanosis, primarily acquired melanosis, conjunctival nevus, and conjunctival melanoma in a Hispanic population.

MATERIALS AND METHODS

A cross-sectional and observational study was undertaken in a tertiary referral ophthalmological center in northern Mexico from December 2020 to April 2021. All patients attending an ophthalmology specialty clinic were screened during their first visit in order to detect melanocytic lesions of the ocular surface. Demographic factors, clinical characteristics, and diagnosis and treatment were recorded.

RESULTS

227 patients were screened for melanocytic lesions. Melanocytic lesions were identified in 114 patients (50.2%). The prevalence of the different melanocytic lesions in the screened population was racial melanosis, 45.3%; primary acquired melanosis, 3.5%, and conjunctival nevus 1.3%. No conjunctival melanoma was identified in the screened population. Primary acquired melanosis was more common in the fifth to sixth decade of life and in females. Racial melanosis showed no gender predilection and was also more common in the fifth to sixth decade of life. Only 1 melanocytic lesion (a primary acquired melanosis) required medical treatment with excisional biopsy and cryotherapy.

CONCLUSION

The prevalence of racial melanosis is remarkably high in the Hispanic population. While less prevalent, primary acquired melanosis is also present in a considerable percentage of Hispanic patients. Both melanocytic lesions exhibit demographic characteristics that match those previously reported in the medical literature.

End-User Skin Analysis (Moles) through Image Acquisition and Processing System

Skin moles and lesions can be the first signs of severe skin diseases such as cancer. This paper presents the development of an end-user device capable of capturing images, segmentation and diagnosis of moles by using the ABCD rule, which stands for analyzing moles' parameters as: asymmetry, border, color, and diameter. These are the main mole characteristics that doctors look at, each of them having a different factor of importance, and depending on these an accurate diagnosis can be given. For the hardware, we developed a small and compact device that can be manipulated easily by anyone without knowledge of medicine, in which we considered a custom-designed 3D enclosure with two white LEDs to control the light. The device has the role of facilitating analysis of the suspicious moles regularly at home, even if only from an indicative and not from a medical point of view. The developed PC software permits the storage of the images in a local database for easy tracking and analysis in time. The image processing developed for the ABCD rule is incorporated into the PC software and tested extensively on the international PH2 database with skin melanoma images to validate our segmentation and criteria evaluation. Using the developed device, we captured mole images for patients, who also took a medical examination by a specialist using the standard dermatoscope. Therefore, we obtained our own database containing 26 images for which we have also the specialists' diagnosis. The performance evaluation measures obtained using our device are-Accuracy: 0.92, Precision: 1.0, Recall: 0.92, F1-score: 0.96.

Adopting low-shot deep learning for the detection of conjunctival melanoma using ocular surface images

BACKGROUND AND OBJECTIVE

The purpose of the present study was to investigate low-shot deep learning models applied to conjunctival melanoma detection using a small dataset with ocular surface images.

METHODS

A dataset was composed of anonymized images of four classes; conjunctival melanoma (136), nevus or melanosis (93), pterygium (75), and normal conjunctiva (94). Before training involving conventional deep learning models, two generative adversarial networks (GANs) were constructed to augment the training dataset for low-shot learning. The collected data were randomly divided into training (70%), validation (10%), and test (20%) datasets. Moreover, 3D melanoma phantoms were designed to build an external validation set using a smartphone. The GoogleNet, InceptionV3, NASNet, ResNet50, and MobileNetV2 architectures were trained through transfer learning and validated using the test and external validation datasets.

RESULTS

The deep learning model demonstrated a significant improvement in the classification accuracy of conjunctival lesions using synthetic images generated by the GAN models. MobileNetV2 with GAN-based augmentation displayed the highest accuracy of 87.5% in the four-class classification and 97.2% in the binary classification for the detection of conjunctival melanoma. It showed an accuracy of 94.0% using 3D melanoma phantom images captured using a smartphone camera.

CONCLUSIONS

The present study described a low-shot deep learning model that can detect conjunctival melanomas using ocular surface images. To the best of our knowledge, this study is the first to develop a deep learning model to detect conjunctival melanoma using a digital imaging device such as smartphone camera.

Dysplastic Nevi: Morphology and Molecular and the Controversies In-between

Dysplastic nevi are distinctive melanocytic lesions in the larger group of atypical nevi. They often are multiple and sporadic with genetic features intermediate between common acquired nevi and melanoma. Dysplastic nevi may be multiple, familial, and seen in patients with familial melanoma syndrome. Although their behavior is benign, they rarely represent a precursor to melanoma. If clinically suspicious, dysplastic nevi should be removed for adequate histopathologic examination and to exclude possibility of melanoma. Partial sampling should be avoided because reliable separation from melanoma requires visualization of the entire lesion to allow for examination of architectural histopathologic features and avoid sampling error.

The Histogenetic Model of Melanoma in the Modern Era of Personalized Medicine

Malignant melanoma (M) can be defined, quite simply, as a malignant neoplasm derived from melanocytes; however, there is great histological and, consequently, clinical variability from case to case (1). In order to try to overcome this intrinsic difficulty, various classification systems have been proposed over the years; as part of this effort, the World Health Organization (WHO) introduced its famous classification about half a century ago (2). Currently, the International Classification of Diseases for Oncology (ICD-O), provided by the WHO International Agency for Research on Cancer (IARC), distinguishes the in situ forms from invasive ones, recognizing four main morphological subtypes: nodular M, superficial spreading M, lentigo maligna M, and acral lentiginous M (3). The ICD-O classification includes further morphological codes, such as: balloon cell M, regressing M, amelanotic M, M in junctional nevus, M in precancerous melanosis, desmoplastic M, neurotropic M, mucosal lentiginous M, M in giant pigmented nevus / congenital melanocytic nevus, mixed epithelioid and spindle cell M, epithelioid cell M, spindle cell M (not otherwise specified), spindle cell melanoma (type A), spindle cell M (type B), and malignant blue nevus (3). Alongside a strictly morphological classification, a histogenetic model, based on the concept of tumor progression, has been regaining ground (4,5). In fact, at the onset, M is characterized by a non-tumorigenic radial growth phase (RGP), inside the epidermis (intraepidermal) or within the papillary dermis (microinvasive), which is devoid of metastatic potential and which may be followed, early or late, by a tumorigenic vertical growth phase (VGP), with deeper extension in the dermis or beyond, nodular confluence, mitotic activity, and metastatic capacity (Table 1). The unique exception to this is nodular M, in which either RGP is rapidly overrun by VGP or the tumor arises directly from dermal melanocytes (6). Today, Breslow depth remains the single most important prognostic factor for clinically localized primary M: it allows us to distinguish M as ultra-thin (≤0.5 mm), thin (≤1 mm), thick (>1 mm), or ultra-thick (>6 mm) (7-10). The systematic application of the histogenetic model to Breslow depth allows us to explain the oft-debated question why some thin M behave aggressively: because they possess an early tumorigenic VGP inside them (11). Moreover, any diagnostic report should be also accompanied by further well-known microstaging attributes, such as Clark level, mitotic count, lymphovascular invasion, perineural infiltration, ulceration, satellitosis, tumor infiltrating lymphocytes, and, if available, sentinel lymph node status (12,13). In conclusion, we believe that a renewed histogenetic approach to M diagnosis deserves wide scientific dissemination in order to achieve better clinical management of individual cases in the era of personalized medicine.

[Ocular manifestations and surgical treatment of the linear nevus sebaceous syndrome]

Objective: To report the clinical and pathological features and surgical treatment of the linear nevus sebaceous syndrome. Methods: It was a retrospective case series study. The clinical records of 11 patients (14 eyes) who were diagnosed as linear nevus sebaceous syndrome between April 2009 and February 2018 at Beijing Tongren Hospital were analyzed. Data collected included sex, age, clinical manifestations, disease site, pathological features, surgical treatment and therapeutic effects. Results: There were six males and five females, aged 6 months to 7 years (mean, 2.8 years). The nevus sebaceous was located at the head (9 patients), face (5 patients) and neck (3 patients). The most common ocular manifestations were blepharocoloboma (13 eyes) and external ocular mass (9 eyes). Surgical treatment was performed in 9 patients (11 eyes), including lid reconstruction in all these eyes, corneal and conjunctival mass resection in four patients (4 eyes), eyelid tumor resection in 5 patients (5 eyes), and symblepharon separation and conjunctival sac reconstruction in 3 patients (5 eyes). Pathological examinations of the external ocular, corneal and conjunctival masses (6 eyes) confirmed the diagnosis of complex choristoma. All operated patients had improved appearance. Conclusions: Linear nevus sebaceous syndrome has characteristic cutaneous lesions and ocular manifestations. Histopathologically, all epibulbar lesions prove to be complex choristomas. The appearance of patients with linear nevus sebaceous syndrome can be significantly improved by oculoplastic surgery. (Chin J Ophthalmol, 2020, 56: 846-852).

Eruptive Halo Naevi: A Possible Indicator of Malignant Disease in a Case Series of Post-Adolescent Patients

Halo naevi are considered benign. They occur in children and adolescents. Eruptive multiple halo naevi are infrequently seen in adults. The first patient in this case series had previously had melanoma. Positron emission tomography-computed tomography (PET-CT) showed a papillary thyroid carcinoma. Subsequent adult patients underwent an examination programme similar to melanoma patients with unknown primary, including PET scanning. Sixteen patients were followed over a 6-year period. In total there were 2 papillary thyroid cancers, 1 neuroendocrine lung tumour, 1 patient had had lung metastases from a thin melanoma 7 years previously, 3 patients had primary cutaneous melanoma (1 had had halo naevi since excision of 2 melanomas 15 years previously) and 1 had melanoma metastasis with unknown primary. The incidence of melanoma was 955 times higher than expected (standardized incidence rate). The benefits of PET scanning must be validated in a controlled trial prior to implementation into clinical practice.

BRAF V600E mutational load as a prognosis biomarker in malignant melanoma

Analyzing the mutational load of driver mutations in melanoma could provide valuable information regarding its progression. We aimed at analyzing the heterogeneity of mutational load of BRAF V600E in biopsies of melanoma patients of different stages, and investigating its potential as a prognosis factor. Mutational load of BRAF V600E was analyzed by digital PCR in 78 biopsies of melanoma patients of different stages and 10 nevi. The BRAF V600E load was compared among biopsies of different stages. Results showed a great variability in the load of V600E (0%-81%). Interestingly, we observed a significant difference in the load of V600E between the early and late melanoma stages, in the sense of an inverse correlation between BRAF V600E mutational load and melanoma progression. In addition, a machine learning approach showed that the mutational load of BRAF V600E could be a good predictor of metastasis in stage II patients. Our results suggest that BRAF V600E is a promising biomarker of prognosis in stage II patients.

Skin Cancer: Precancers

Actinic keratoses (AKs) are common skin lesions caused by cumulative sun exposure. Rates of lesion progression to squamous cell carcinoma (SCC) have been reported to be between 0.025% and 16%, some lesions may regress. Atypical moles are melanocytic nevi that indicate a higher risk of melanoma and, on rare occasions, transform into malignant melanoma, particularly in patients with dysplastic nevus syndrome or familial atypical multiple mole-melanoma syndrome. Precancerous lesions can be identified by physical examination; diagnostic accuracy is enhanced by dermatoscopy. Biopsy is indicated when definitive diagnosis is deemed necessary for suspicious lesions. AKs can be managed with surgical methods, topical chemotherapeutic drugs, or photodynamic therapy. Complications of AKs include itching, pain, cosmetic concerns, and progression to SCC. Management of dysplastic nevi depends on the degree of atypia present. Lesions may be observed in cases of mild atypia with positive histologic margins but negative clinical margins. Dysplastic nevi with a high degree of atypia should be surgically excised or the patient should be referred to a dermatology subspecialist. Complications of atypical nevi include cosmetic concerns, recurrence, and rare progression to melanoma. Surveillance of precancerous lesions should include patient self-examination and regular follow-up skin examinations performed by the physician.