Digital quantification of PRAME for distinguishing melanoma from nevi compared to manual assessment.

AIMS: In this proof-of-concept study, we propose a new method for automated digital quantification of PRAME (PReferentially expressed Antigen of MElanoma) as a diagnostic aid to distinguish between benign and malignant melanocytic lesions. The proposed method utilizes immunohistochemical virtual double nuclear staining for PRAME and SOX10 to precisely identify the melanocytic cells of interest, which is combined with digital image analyse to quantify a PRAME-index. METHODS: Our study included 10 compound nevi, 3 halo nevi, and 10 melanomas. Tissue slides were stained with PRAME, scanned, the cover glass removed, stained with SOX10, scanned again, and finally analysed digitally. The digitally quantified PRAME-index was compared with a manual qualitative assessment by a dermatopathologist using the standard PRAME-scoring system. RESULTS: The digitally quantified PRAME-index showed a sensitivity of 70 % and a specificity of 100 % for separating melanomas from benign lesions. The manual qualitative PRAME-score showed a sensitivity of 60 % and a specificity of 100 %. Comparing the two methods using ROC-analyses, our digital quantitative method (AUC: 0.931, 95 % CI: 0.834;1.00, SD: 0.050) remains on par with the manual qualitative method (AUC: 0.877, 95 % CI: 0.725;1.00, SD: 0.078). CONCLUSION: We found our novel digital quantitative method was at least as precise at classifying lesions as benign or malignant as the current manual qualitative assessment. Our method has the advantages of being operator-independent, objective, and replicable. Furthermore, our method can easily be implemented in an already digitalized pathology department. Given the small cohort size, more studies are to be done to validate our findings.

Giant Cerebriform Nevus Lipomatosus Cutaneous- Superficialis with Diffuse Lipomatosis: An Unusual Presentation on the Neck.

A 25-year-old man presented with gradually increasing swelling of 15 years' duration on the left side of his neck. There had been occasional foul-smelling discharge from the swelling. Local examination revealed an 8 cm × 5 cm oblong-shaped, yellowish to skin-colored, soft, -cerebriform swelling. There were multiple open comedones (Figure 1a). The surrounding skin had small and soft skin-colored papules. On palpation, there was no ulceration, tenderness, induration, or bag of worms. A scar from the past surgery was visible. Systemic examina- tion was unremarkable. The differential diagnosis demonstrated plexiform neurofibroma and nevus lipomatosus cutaneous superficialis (NLCS; Figure 2).

PRAME and Historical Immunohistochemical Antibodies Ki-67, P16, and HMB-45 in Ambiguous Melanocytic Tumors.

ABSTRACT: Ambiguous melanocytic lesions/tumors (AMLs) can be simply described as melanocytic neoplasms that cannot be differentiated as either a melanoma or a nevus. Preferentially expressed antigen in melanoma (PRAME) is a novel antibody that can help differentiate between nevi and melanomas. However, its usefulness remains controversial in AMLs. The aim of this study was to demonstrate the importance of PRAME and diagnostic auxiliary antibodies (Ki-67, p16, HMB-45) in the diagnosis of melanocytic lesions, especially in AMLs. This study included 52 ambiguous melanocytic lesions, 40 nevi, and 40 melanomas. All immunohistochemical studies were performed automatically using the Universal Alkaline Phosphatase Red Detection Kit. Different analytic approaches were used for each antibody based on the literature. Statistically, the multinomial forward stepwise elimination logistic regression analysis was used to create a statistical model to predict the diagnosis of melanocytic lesions based on clinical, morphological, and immunohistochemical data. PRAME positivity was very strong and diffuse in the melanoma group and statistically significantly higher than that of the AML and nevus groups. There was no statistically significant difference between the nevus and AML groups. The Ki-67 proliferation index and HMB-45 staining pattern provided valuable indications for distinguishing between these 3 groups. The P16 antibody was limited in supporting the differential diagnosis. Our statistical model showed that a high mitosis count, central pagetoid spread, and PRAME positivity increased the probability of melanoma against an AML diagnosis. This study showed the advantages of evaluating the PRAME antibody together with morphological features and other immunohistochemical markers (Ki-67 and HMB-45) in the differential diagnosis of melanocytic lesions.

Nevi and Melanoma.

Cutaneous melanoma is an aggressive form of skin cancer derived from skin melanocytes and is associated with significant morbidity and mortality. A significant fraction of melanomas are associated with precursor lesions, benign clonal proliferations of melanocytes called nevi. Nevi can be either congenital or acquired later in life. Identical oncogenic driver mutations are found in benign nevi and melanoma. While much progress has been made in our understanding of nevus formation and the molecular steps required for transformation of nevi into melanoma, the clinical diagnosis of benign versus malignant lesions remains challenging.

Prenatal recognition of cerebriform sebaceous naevus.

Cerebriform sebaceous naevus (CSN) is a rare morphological sebaceous naevus variant and challenging to diagnose prenatally due to its flat, smooth and waxy appearance and lack of association with extracutaneous manifestations.A multigravida was referred to our tertiary obstetric unit at 24 weeks of gestation for evaluation of fetal auricular lesions. We were able to further characterise the lesions via serial obstetric ultrasound imaging with the aid of three-dimensional (3D) technology. Although the precise diagnosis prenatally was uncertain, the use of 3D technology allowed the reconstruction of the fetal cutaneous lesions for multidisciplinary assessment to facilitate the development of a neonatal management plan. The diagnosis of CSN was made postnatally on biopsy.

Correlation between super-high magnification (400x) dermoscopy and reflectance confocal microscopy for the diagnosis of melanosis and other pigmented genital lesions.

The clinical diagnosis of pigmented genital lesions is challenging. Reflectance confocal microscopy (RCM) is effective for diagnosis but is limited in its application due to elevated costs. A more affordable dermatoscope with a 400x magnification (D400) has recently been brought to market. The aim of our study was to compare these two imaging techniques for the analysis of pigmented genital tumours. An observational, prospective and mono-centric study was carried out from October 2017 to May 2019, in which clinical, dermatoscopic (20x and 400x) and RCM data from 207 pigmented genital lesions were collected. The images generated via D400 and RCM were analysed by three expert investigators. Similarities between the criteria observed using D400 and RCM were evaluated by each investigator. In total, 207 lesions were included: 183 melanosis, 19 nevi, one basal cell carcinoma (BCC), two condylomas and two melanomas in situ. Our series correlates well with data found in the literature especially for the distribution of different lesions, their topography, and their aspect using x20 dermatoscopy and RCM. Pattern and cell criteria defined using RCM largely paralleled those observed with D400 for all three investigators. Correlation between D400 and RCM was moderate to strong with regards to the identification of the ring pattern and clustered round cells, strong for dendritic and plump cells, and perfect for isolated round cells and spindle cells. D400 is an easy-to-use, cost-effective alternative for the analysis of pigmented genital lesions, particularly for melanosis.

Rate of Benign and Malignant Secondary Tumors Associated With Nevus Sebaceous: A Systematic Review and Meta-Analysis.

BACKGROUND: Nevus sebaceous (NS) is a rare congenital skin lesion affecting approximately 0.3% of all newborns. Although benign, NS lesions can harbor malignant secondary tumors. The published rate of development of these malignant tumors varies. This meta-analysis aimed to identify the rate of malignant and benign secondary neoplasms occurring in NS. METHODS: A literature search was conducted using PubMed, Embase, and Web of Science from inception to April 2023. Eligible studies reported incidence or risk of secondary neoplasms in patients with NS. Two independent reviewers screened studies, extracted data, and assessed the quality of included studies. The primary outcome was the pooled incidence of secondary neoplasms. Studies with sample sizes greater than 50 patients were eligible for meta-analysis using the random-effects model. RESULTS: Twenty-eight studies were identified, 22 of which were eligible for meta-analysis. The overall rate of secondary neoplasms was 12.8% (95% confidence interval [Cl], 9.2%-17.6%). The rates of development of malignant and benign tumors were 2.4% (95% CI, 1.4%-4.1%) and 10.3% (95% CI, 7.5%-13.9%), respectively. The rate of development of basal cell carcinoma was 1.7% (95% CI, 0.9%-3.2%), whereas the rate of the development of syringocystadenoma papilliferum was 3.6% (95% CI, 2.5%-5.3%) and that if trichoblastoma was 2.6% (95% CI, 1.7%-3.8%). CONCLUSIONS: Although the rate of development of malignant tumors within a primary NS lesion is low, it is not negligible. Prophylactic early excision remains a viable approach to prevent secondary malignant neoplasms, address cosmetic and functional complications, and preempt the need for complex reconstruction in the future. We propose that resection of NS lesions in childhood remains a reasonable first-line option in the appropriate patient keeping in mind that it may leave an undesirable scar.

Clinical and Dermoscopic Insights Into Scalp Nevi in Chinese Children.

BACKGROUND: The presence of scalp nevi in children frequently causes apprehension, leading physicians and parents to consider unnecessary biopsies or excisions of scalp nevi in children. There are limited data on the dermoscopic characteristics of scalp nevi in Chinese children. OBJECTIVE: The aim of this study was to comprehensively analyze the clinical and dermoscopic features of scalp nevi in this specific population of Chinese pediatric patients, with a focus on a single pediatric dermatologic surgery practice. METHODS: This retrospective cohort study investigated patients who underwent surgical excision of scalp nevi. All patients underwent dermoscopy with photographic documentation. RESULTS: Seventy-two scalp nevi in 56 Chinese children were included. Notably, no melanoma cases were detected. The parietal region (35, 48.6%) was the most frequently affected anatomical site. Clinical asymmetry was more prevalent in nevi with a diameter exceeding 6 mm ( p < .05). The predominant dermoscopic pattern observed was the globular pattern (50, 69.4%) while an intriguing rarity of a reverse-eclipse pattern (1, 1.4%). CONCLUSION: This study revealed that scalp nevi in Chinese children usually did not exhibit concerning behavior. Increasing awareness of the clinical characteristics, dermoscopic features, and the natural progression of scalp nevi in children can potentially help reduce unnecessary surgical interventions.

Giant congenital fibroblastic connective tissue nevus associated with vascular anomalies.

We described an unusual combination of fibroblastic connective nevus (FCTN) already present at birth with underlying vascular anomalies. Overall, the lesion appeared as a large purplish-brown mass in the groin region up to the third of the right thigh, with partial spontaneous regression during the first three months of life. The FCTN observed exhibited several unusual characteristics: it was congenital, large in size, and located in the lower limbs. Finally, it represented the first case described in which an FCTN arose in association with vascular anomalies.

PRAME Expression in Melanocytic Proliferations in Special Sites.

The subset of nevi occurring at special sites (eg, acral skin, anogeni-tal region, breast, ear, flexural surfaces) have normal histologic variations that preclude the use of routinely used diagnostic criteria for malignancy. Suggested criteria for differentiating malignant special-site lesions from benign lesions have been described, but there is an unmet need for a validated test aiding in the delineation of benign and malignant lesions at special sites. Preferentially expressed antigen of melanoma (PRAME) expression has been characterized as a relatively specific marker of melanoma, but not within the specific population of special-site lesions. This study aimed to determine if PRAME may serve as a specific marker of melanoma within the population of special-sites lesions.

Thickness of melanocytes in giant congenital melanocytic nevus for complete surgical excision: clinicopathological evaluation of 117 lesions according to the area and size.

BACKGROUND: Giant congenital melanocytic nevi (GCMN) are usually defined as nevi that exceed 20 cm in maximal diameter or 15% of the total body surface area. There have been reports of life-long malignant change risks arising from GCMN, leading to surgical excision of GCMN. This study aims to evaluate the thickness of melanocytes based on clinical factors in order to provide objective information for the complete resection of the lesion. METHODS: Overall, 75 patients diagnosed with GCMN between 2000 and 2021 were included, and their clinical records were collected retrospectively. 117 pathologic slides obtained during excision were reviewed to measure nevus thickness. Clinical factors were assessed with a generalized estimated equation model for association with nevus thickness. RESULTS: The thickness of nevus was significantly associated with the location and size. Nevus thickness was more superficial in the distal extremity than in the head and trunk (P = 0.003 [head]; P < 0.001 [trunk]; P = 0.091 [Proximal extremity]). Nevi sized 60 cm or more were significantly deeper than those measuring 20-29.9 cm (P = 0.035). An interaction between size and location existed (P < 0.001). Trunk and distal extremity lesions consistently exhibited uniform thickness regardless of lesion size, whereas head and proximal extremity lesions showed variations in thickness based on lesion size. CONCLUSION: GCMNs have differences in thickness according to location and size. Therefore, it is necessary to devise an approach optimized for each patient to treat GCMN. In the study, it was emphasized that the thickness of GCMN is correlated with clinical factors, specifically the location and size of the nevus. Consequently, these findings underscore the need for individualized treatment plans for effective surgical intervention.

Risk factors of lentigo maligna as compared to other melanoma subtypes.

BACKGROUND: Lentigo maligna (LM) exhibits a particular epidemiological profile compared to other histopathologic subtypes of melanoma, with a propensity for the head and neck area and a higher mean age at diagnosis. Few small-scale studies have exclusively evaluated the risk factors for the development of LM. OBJECTIVE: This study aims to compare LM to other histological subtypes of melanoma for the prevalence of known melanoma risk factors, including pigmentary characteristics, history of occupational sun exposure, nevus count, and familial melanoma history. PATIENTS AND METHODS: We conducted a case-control study of 152 patients with LM and 784 patients with other melanoma subtypes (OM). The Mann-Whitney t-test and Pearson chi-squared test were used to detect differences between the two groups in continuous and categorical variables, respectively. Univariate and multivariate logistic regression models were then constructed to identify risk factors for developing LM compared to other melanoma subtypes. RESULTS: In multivariate logistic regression analysis, LM was positively associated with a lentigines count >50 and occupational sun exposure compared to OM (OR 2.10, 95% CI 1.35-3.29 and OR 2.18, 95% CI 1.33-3.57, respectively). In contrast, patients with an increased nevus count and fair or medium skin color were less likely to develop LM than OM (OR 0.93, P < 0.001, 95% CI 0.91-0.94, and OR 0.28, P < 0.001, 95% CI 0.17-0.46, respectively). In univariate analysis, LM exhibited a weaker association with all pigmentary traits than OM. No significant associations were found for atypical nevi count and family history. CONCLUSION: We found significant differences in the prevalence of known melanoma risk factors between LM and other melanoma subtypes, which supports the hypothesis of a distinct pathogenetic pathway of LM.

BioMEL: a translational research biobank of melanocytic lesions and melanoma.

INTRODUCTION: Diagnosing invasive cutaneous melanoma (CM) can be challenging due to subjectivity in distinguishing equivocal nevi, melanoma in situ and thin CMs. The underlying molecular mechanisms of progression from nevus to melanoma must be better understood. Identifying biomarkers for treatment response, diagnostics and prognostics is crucial. Using biomedical data from biobanks and population-based healthcare data, translational research can improve patient care by implementing evidence-based findings. The BioMEL biobank is a prospective, multicentre, large-scale biomedical database on equivocal nevi and all stages of primary melanoma to metastases. Its purpose is to serve as a translational resource, enabling researchers to uncover objective molecular, genotypic, phenotypic and structural differences in nevi and all stages of melanoma. The main objective is to leverage BioMEL to significantly improve diagnostics, prognostics and therapy outcomes of patients with melanoma. METHODS AND ANALYSIS: The BioMEL biobank contains biological samples, epidemiological information and medical data from adult patients who receive routine care for melanoma. BioMEL is focused on primary and metastatic melanoma, but equivocal pigmented lesions such as clinically atypical nevi and melanoma in situ are also included. BioMEL data are gathered by questionnaires, blood sampling, tumour imaging, tissue sampling, medical records and histopathological reports. ETHICS AND DISSEMINATION: The BioMEL biobank project is approved by the national Swedish Ethical Review Authority (Dnr. 2013/101, 2013/339, 2020/00469, 2021/01432 and 2022/02421-02). The datasets generated are not publicly available due to regulations related to the ethical review authority. TRIAL REGISTRATION NUMBER: NCT05446155.

Neonatal cutaneous melanoma with cutaneous metastasis: a case report and review of literature.

Malignant melanoma, a rare skin cancer in children, primarily affects individuals over 10 years old. Giant congenital nevi, found in about 1% of newborns, increases the risk. However, the development of melanoma from a pre-existing giant congenital nevus diagnosed during the neonatal period is exceptionally rare. We present a case of congenital melanoma in a newborn, where nodules grew on an existing nevus on the baby's back. Literature on managing such cases was reviewed. This case highlights the importance of considering malignant transformation in congenital nevi and the challenges in their management. Due to limited reported cases over 80 years, conclusive findings on survival and treatment options are difficult to provide. Clinicians should report outcomes to develop a management algorithm for neonatal melanoma. Further studies are needed to enhance understanding of causes and treatment for patients with congenital giant hairy nevi and associated melanoma.

Comparative Quantitative Proteomic Analysis of Melanoma Subtypes, Nevus-Associated Melanoma, and Corresponding Nevi.

A substantial part of cutaneous malignant melanomas develops from benign nevi. However, the precise molecular events driving the transformation from benign to malignant melanoma are not well-understood. We used laser microdissection and mass spectrometry to analyze the proteomes of melanoma subtypes, including superficial spreading melanomas (n = 17), nodular melanomas (n = 17), and acral melanomas (n = 15). Furthermore, we compared the proteomes of nevi cells with those of melanoma cells within the same specimens (nevus-associated melanoma (n = 14)). In total, we quantified 7935 proteins. Despite the genomic and clinical differences of the melanoma subtypes, our analysis revealed relatively similar proteomes, except for the upregulation of proteins involved in immune activation in nodular melanomas versus acral melanomas. Examining nevus-associated melanoma versus nevi, we found 1725 differentially expressed proteins (false discovery rate < 0.05). Among these proteins were 140 that overlapped with cancer hallmarks, tumor suppressors, and regulators of metabolism and cell cycle. Pathway analysis indicated aberrant activation of the phosphoinositide 3-kinase-protein kinase B-mTOR pathways and the Hippo-YAP pathway. Using a classifier, we identified six proteins capable of distinguishing melanoma from nevi samples. Our study represents a comprehensive comparative analysis of the proteome in melanoma subtypes and associated nevi, offering insights into the biological behavior of these distinct entities.

Fusion between an Algorithm Based on the Characterization of Melanocytic Lesions' Asymmetry with an Ensemble of Convolutional Neural Networks for Melanoma Detection.

Melanoma is still a major health problem worldwide. Early diagnosis is the first step toward reducing its mortality, but it remains a challenge even for experienced dermatologists. Although computer-aided systems have been developed to help diagnosis, the lack of insight into their predictions is still a significant limitation toward acceptance by the medical community. To tackle this issue, we designed handcrafted expert features representing color asymmetry within the lesions, which are parts of the approach used by dermatologists in their daily practice. These features are given to an artificial neural network classifying between nevi and melanoma. We compare our results with an ensemble of 7 state-of-the-art convolutional neural networks and merge the 2 approaches by computing the average prediction. Our experiments are done on a subset of the International Skin Imaging Collaboration 2019 dataset (6296 nevi, 1361 melanomas). The artificial neural network based on asymmetry achieved an area under the curve of 0.873, sensitivity of 90%, and specificity of 67%; the convolutional neural network approach achieved an area under the curve of 0.938, sensitivity of 91%, and specificity of 82%; and the fusion of both approaches achieved an area under the curve of 0.942, sensitivity of 92%, and specificity of 82%. Merging the knowledge of dermatologists with convolutional neural networks showed high performance for melanoma detection, encouraging collaboration between computer science and medical fields.