Congenital Nevi Research Articles

The W-Plasty Serial Excision Method for Treating Medium Congenital Melanocytic Nevi: A Retrospective Analytical Study.

Serial excision remains the most commonly used surgical procedure for treating congenital melanocytic nevus (CMN). It is critical to remove as much of the lesion as possible with each procedure to reduce the number of procedures and to shorten the treatment duration. To investigate the clinical efficacy of W-plasty serial excision for the repair of postoperative CMN defects. A retrospective analysis of patients with medium CMN was conducted from April 2018 to March 2022. Treatment options were divided into elliptical serial excision (10 cases) and W-plasty serial excision (10 cases). Follow-up occurred over 6 months. The number of elliptical excision procedures was 2 to 4 (mean 2.9). The scar-to-lesion length ratio was 1.5 to 2.0 (mean 1.7). The mean Vancouver Scar Scale (VSS) score was 5.40 ± 0.42. The number of W-plasty excision procedures was 2 to 3 (mean 2.2). The scar-to-lesion length ratio was 1.2 to 1.5 (mean 1.4). The mean VSS score was 2.70 ± 0.26. W-plasty excision was superior to elliptical excision regarding the number of procedures and the effect on postoperative scars. W-plasty serial excision can be considered a suitable option for the excision of medium CMN, leading to excellent results.

Giant congenital melanocytic nevus of the back: a case report

BackgroundGiant congenital melanocytic nevus (GCMN) is a rare disease with an extremely low incidence, that is present from or develops at birth and typically affects the dermis but may also affect other skin layers. Its incidence is estimated at <1 in 20,000 newborns. Despite its rarity, this lesion is important because it may be associated with severe complications such as malignant melanoma. A thorough follow-up is crucial since the probability of malignancy can vary depending on the clinical course. As such, careful observation is necessary to support possible management plans. Case DescriptionIn this case report, we present a three-day-old newborn male with abrasions on a black patch on his back. He presented with fever, jaundice, and black patches on more than 50% of his trunk down to the sacral area. The black raised patches resembling nodules had wounds on the lower back near the gluteus. A histopathology examination of specimens taken from 3 nodules on the back revealed hypocellular tissues with lymphocytes, histiocytes, neutrophils, fat droplets, and mature fat cells interspersed with some erythrocytes. The lesion was, therefore, diagnosed as a giant congenital melanocytic nevus (GCMN). Parents were counseled regarding the possible future course and were asked to come for regular follow-ups. Conclusions In this instance, we document a rare occurrence of GCMN that warrants recognition and appropriate treatment. To accumulate evidence for improving disease prognosis and outcomes, children with congenital melanocytic nev

Application of dermoscopy and reflectance confocal microscopy in vivo in the evaluation of nevi in children.

Melanocytic nevi are frequently observed in the pediatric population. While newly acquired nevi can appear during childhood, congenital nevi can continue to grow and clinically change, making patient caregivers concerned. Reflectance confocal microscopy (RCM) in vivo is a noninvasive tool that might enhance the diagnostic accuracy of dermoscopy, reducing the rate of unnecessary surgical procedures. This study aimed to assess the utility of RCM in increasing the diagnostic accuracy of pediatric melanocytic nevi that show pigmentation changes or grow rapidly. Pediatric patients who presented between January 2022 and February 2023 in a single institution with rapidly growing melanocytic nevi or nevi that presented changes in the pigmentation were included in the study. All nevi were evaluated by means of dermoscopy and RCM. Forty-two patients with a total of 42 melanocytic nevi were included. Most lesions showed a honeycombed pattern (n = 21, 50%). On RCM, only 3 of 42 nevi presented atypical cells within the epidermis (7.1%). Evaluation of the dermoepidermal junction (DEJ) revealed the predominance of the meshwork pattern (n = 22, 52.4%). Notably, features considered significant for atypical melanocytic nevi included 9 nevi with scant atypical melanocytes (21.4%) and 3 nevi with nonedge papillae (7.1%). None of the studied lesions required biopsy among this cohort. Most rapidly growing and clinically changing nevi rarely exhibit single atypical cells in the DEJ. The RCM served as a valuable adjunct to dermoscopy, allowing reassurance in the evaluation of these lesions.

A rare case of spotted grouped pigmented naevus: Congenital follicular melanocytic naevus.

A rare case of spotted grouped pigmented naevus: Congenital follicular melanocytic naevus.

Acellular dermal matrix-assisted tissue expansion for giant congenital melanocytic nevi of the extremities and trunk in pediatric patients.

Tissue expansion for treating giant congenital melanocytic nevi (GCMN) is a commonly employed surgical method. However, the procedure's efficacy is often hindered by anatomical and histological characteristics as well as blood supply, particularly in the extremities and trunk. Enhancing expansion efficiency while reducing complications is thus a topic to be investigated, especially for pediatric patients undergoing rapid physical and psychological development with higher risks of non-compliance to medical instructions. To explore the effectiveness of expansion in extremities and trunk by immobilizing the acellular dermal matrix (ADM) in the gravitational force zone of inflating expanders. All patients involved in this research underwent ADM-assisted tissue expansion in either the extremities or trunk. ADM was fully flattened, securely fixed to the lower pole of the expander, and subsequently attached to the inner surface of the expanding flap. From 2021 to 2023, a total of nine pediatric patients with GCMN underwent the ADM-assisted tissue expansion. All patients achieved the desired expanding volume without experiencing petechiae, ecchymosis, or skin ulceration in the ADM-covered area. The process was well tolerated by all patients, with no reports of itching, pain, allergic reaction, or fever. During the flap transfer, the ADM was observed to be firmly adhered to the expanding flap with discernible capillary network. ADM-assisted tissue expansion demonstrates promise in augmenting expansion efficiency and reducing the time needed for surgical intervention in the extremities and trunk, thereby presenting significant clinical value for pediatric patients afflicted with GCMN.

Erbium: YAG laser treatment efficacy and association with histologic features for giant congenital melanocytic nevi management.

Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN). We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response. Between 2019 and 2022, we enrolled 30 medium-to-giant CMN patients who underwent Er: YAG laser treatment. All patients received biopsies before and after laser treatments. Clinical efficacy outcomes were evaluated by the investigator's global assessment (IGA), 5-point scale of depigmentation, and Vancouver Scar Scale (VSS) scores at least 6 months after treatment. Of the 30 cases, 18 (60.0%) showed improvement (IGA score ≥3). Eight (26.7%) patients showed repigmentation. Eight (26.7%) patients developed hypertrophic scars. The average IGA, depigmentation, and VSS scores were 2.93, 3.57, and 3.20. The IGA score was higher (3.24 ± 1.18 vs. 2.22 ± 0.97, p = 0.031) and a lower repigmentation rate (14.3% vs. 55.6%, p = 0.032) was observed in the cases with Grenz zone. The IGA score was higher (3.33 ± 1.24 vs. 2.13 ± 0.89, p = 0.023) and the repigmentation rate was lower (11.1% vs. 50.0%, p = 0.034) also in the cases with the melanocytes nests with aggregation of melanin. Lesions with superficial ablation resulted in less hypertrophic scar formation than those with deep ablation (5.9% vs. 53.8%, p < 0.05). The Er: YAG laser demonstrated effective clinical results for GCMNs. The grenz zone and the melanocytes nests with aggregation of melanin are promising predictors of laser efficacy.

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

BackgroundGiant 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.MethodsOverall, 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.ResultsThe 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.ConclusionGCMNs have differences in thickness according to location and size. Therefore, it is necessary to devise an approach optimized for each patient to treat GCMN.Mini-abstractIn 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.

What are congenital melanocytic nevi?

Congenital melanocytic nevi (CMN) are special types of moles. CMN happen when extra pigment-making cells (melanocytes) grow in a baby's skin while the baby is forming before birth. They are not caused by anything their parent did or didn't do during pregnancy. These moles are there when the baby is born, stay on the skin for life, and grow as the child grows.

Spatial transcriptomic analysis of tumour-immune cell interactions in melanoma arising from congenital melanocytic nevus.

Studies on the interaction between tumour-infiltrating immune cells (TIICs) and tumour cells in melanoma arising from congenital melanocytic nevus (CMN) are lacking. The aim of this study was to determine the intratumoral immune landscape of TIICs and tumour cells during invasion and metastasis. Tissue specimens were obtained from patients with melanoma originating from CMN. Differential gene expression in melanoma cells and TIICs during invasion and metastasis was determined using spatial transcriptomics. As invasion depth increased, the expression of LGALS3, known to induce tumour-driven immunosuppression, increased in melanoma cells. In T cells, the expression of genes that inhibit T-cell activation increased with increasing invasion depth. In macrophages, the expression of genes related to the anti-inflammatory M2 phenotype was upregulated with increasing invasion depth. Compared to primary tumour cells, melanoma cells in metastatic lesions showed upregulated expression of genes associated with cancer immune evasion, including AXL and EPHA2, which impede T-cell recruitment, and BST2, associated with M2 polarization. Furthermore, T cells showed increased expression of genes related to immunosuppression, and macrophages exhibited increased expression of genes associated with the M2 phenotype. The interaction between melanomas arising from CMN and TIICs may be important for tumour progression and metastasis.

Serial Tissue Expansion and Skin Grafts in the Management of a Giant Congenital Nevus of the Face: Review of Literature and Case Report.

Giant congenital nevi, especially on the head and neck, pose a challenge for plastic surgeons. This requires extensive experience in detailed planning, combining different techniques, and selecting appropriate materials for reconstruction. There have been reports of using a tissue expander, serial resection method, and full-thickness skin grafts for this type of nevus. However, the best way to completely remove a giant congenital nevus is endless. In this article, we would like to present a case of a left hemifacial giant congenital nevus in which we used multiple tissue expansion to fully replace the nevus, along with some of our modification techniques.

Metabolomic analysis reveals the biological characteristics of giant congenital melanocytic nevi

Giant congenital melanocytic nevi (GCMN) is a congenital cutaneous developmental deformity tumor that usually occurs at birth or in the first few weeks after birth, but its pathogenesis is still unclear. In this study, nuclear magnetic resonance-based metabolomics strategy was employed to evaluate the metabolic variations in serum and urine of the GCMN patients in order to understand its underlying biochemical mechanism and provide a potential intervention idea. Twenty-nine metabolites were observed to change significantly in serum and urine metabolomes, which are mainly involved in a variety of metabolic pathways including glyoxylate and dicarboxylate metabolism, TCA cycle and metabolisms of amino acids. The substantial cores of all the disturbed metabolic pathways are related to amino acid metabolism and carbohydrate metabolism and regulate the physiological state of the GCMN patients. Our results provide the physiological basis and physiological responses of GCMN and will be helpful for better understanding the molecular mechanisms of GCMN in future research.

KISSING NEVUS RECONSTRUCTION WITH A SUPRACLAVICULAR GRAFT: A RARE CASE REPORT

Introduction : Kissing nevus is a rare form of congenital nevus that occurs on upper and lower eyelid of one eye, forming a large nevus when the eyelids are closed. This condition causes functional and aesthetic problems thus the reconstruction is essential.&#x0D; Case Illustration : A 23-years old female presented to our ophthalmology outpatient clinic with complain of having painless, black colored, non-progressive nevus over left upper and lower eyelids since birth that cosmetically unpleasing. The dark brown-black colored was sized 55x30 mm with hypertrichosis covering approximately two third of both left upper and lower eyelid margins and extending to cheek. The entire nevus was excised and reconstructed by supraclavicular full thickness skin graft, lateral canthopexy and canthoplasty. Three weeks after operation showed satisfactory results. Histological examination revealed intradermal nevus pigmentosus.&#x0D; Discussion : The reconstruction of eyelid after excision remains a challenge because of its specialized function and cosmetic significance. Ideally, the reconstruction should provide a stable eyelid margin, protect the ocular surface, and sustain mobility. Free skin grafts harvested from the control lateral eyelid, postauricular, supraclavicular, and upper arm region have been the most common reconstructive approach. The supraclavicular area is a reliable donor option to cover large head and neck defects due to its similarity in colour, thickness, and flexibility.&#x0D; Conclusion : Free supraclavicular graft is safe, reliable and cosmetically acceptable choice for reconstruction head and neck defects.

Clinical study on the role of platelet-rich plasma in human acellular dermal matrix with razor autologous skin graft repair of giant congenital pigmented nevus in children

BackgroundNA ObjectiveEvaluate the safety and feasibility of platelet-rich plasma (PRP) in the treatment of giant congenital melanocytic nevi (GCMN) in children with human acellular dermal matrix (HADM) transplantation. Patients and MethodsA total of 22 children with GCMN were included in the study. They were divided into an experimental and a control group. The experimental group used the method of HADM with Razor Autologous Skin Graft combined with PRP to repair skin and soft tissue defects after giant nevus resection (Group A, n = 11). The control group was treated with HADM with Razor Autologous Skin Graft (Group B, n = 11) only. To compare the survival rate of skin grafts, we used the Vancouver Scar Scale (VSS) for the postoperative skin graft area and the Patient and Observer Scar Assessment Scale (POSAS) to compare the two groups of patients. ResultsThere was no statistically significant difference in age, gender, location of giant nevi, and pathological classification between Group A and Group (P > 0.05). The survival rate of skin grafting and the VSS and POSAS scores of scar tissue in group A were superior to those of group B (P < 0.05). ConclusionsPRP has improved the survival rate of composite skin grafting in children with GCMN, and long-term satisfactory prognosis of scar healing. Therefore, we consider this treatment method a valuable contribution to clinical practice.

Missense mutation of NRAS is associated with malignant progression in neurocutaneous melanosis

Neurocutaneous melanosis (NCM) is a rare congenital neurocutaneous syndrome characterized by congenital melanocytic nevus of skin and abnormal proliferation of leptomeningeal melanocytes. Early acquisition of post-zygotic somatic mutations has been postulated to underlie the pathogenesis of NCM. The pathogenesis of NCM remains to be fully elucidated, and treatment options have not been established. Here, we report for the first time, multiregional genomic analyses in a 3-year-old autopsied girl with leptomeningeal melanomatosis associated with NCM, in which a ventriculo-peritoneal (VP) shunt was inserted for the treatment of hydrocephalus. The patient expired six months after the onset due to respiratory failure caused by abdominal dissemination via VP shunt. We performed multiregional exome sequencing to identify genomic differences among brain and abdominal tumors, nevus, and normal tissues. A total of 87 somatic mutations were found in 71 genes, with a significantly large number of gene mutations found in the tumor site. The genetic alterations detected in the nevus were only few and not shared with other sites. Three mutations, namely GNAQ R183Q, S1PR3 G89S and NRAS G12V, considered pathogenic, were found, although S1PR3 mutations have not been previously reported in melanocytic tumors. GNAQ and S1PR3 mutations were shared in both tumor and normal sites. Moreover, the mutant allele frequencies of the two mutations were markedly higher in tumor sites than in normal sites, with copy-neutral loss-of-heterozygosity (CN-LOH) occurring in tumor. NRAS mutation was found only in the abdominal tumor and was thought to be responsible for malignant progression in the present case. Multiregional comprehensive genetic analysis may lead to discovering novel driver mutations associated with tumorigenesis and targeted therapy.

O09 Targeted genetic therapy for congenital melanocytic naevi

Abstract Severe cases of congenital melanocytic naevi (CMN) are associated with substantial cutaneous and neurological morbidity and an excess childhood mortality from melanoma. Effective treatments are lacking. This mosaic disorder is caused most commonly by a heterozygous oncogenic variant NRAS c.181C&amp;gt;A, p.(Q61K). As NRAS has multiple downstream effectors we have sought to treat this disease by precision genetic therapy rather than downstream pathway inhibition, hypothesising that silencing of the oncogenic allele may remove cellular protection from RAS induced apoptosis. Using a lead siRNA selected for allele specificity and fewest off-target effects on RNAseq (siNRASQ61K) we show here significant selective knockdown of variant mRNA expression and knockdown of NRAS protein levels. A single treatment to primary naevus cell cultures leads to normalisation of MAPK pathway activation, reduction in proliferation rate, and importantly, triggering of apoptosis. We go on to demonstrate that receptor-targeted lipid nanoparticles (RTNPs) successfully protect siRNA from degradation, deliver cargo to naevus cells in patient skin explants and improve naevus cell targeting. A single intradermal injection of siNRASQ61K-RTNPs into transgenic mice harbouring humanised NRASQ61K(Tyr::NRASQ61K) confirms significant selective knockdown of the variant NRAS allele in vivo.Successful targeting of variant NRAS and triggering of naevus cell apoptosis now paves the way for clinical trials of this genetic therapy for CMN.

Therapeutic management of akissing nevus of the eyelid

Congenital divided melanocytic nevi of the upper and lower eyelid are rare pigmented changes of the eyelids. These processes are also known as "kissing nevi," "panda nevi," and "split ocular nevi," and were first described by Fuchs in 1919. About 120cases have been described in the literature so far. Congenital melanocytic nevi are either present at birth (small nevi are already found in about 1% of neonates) or manifest predominantly during the first decade of life. These rare melanocytic changes of the eyelids should be controlled regularly, as malignant transformation can occur. The actual incidence of malignant transformation is highly variable in the literature, ranging from 2 to 40% depending on the duration of follow-up, with an average of 14% for the whole lifetime. Moreover, nevi of the eyelids may be considered cosmetically disturbing and cause functional problems. Therapeutic removal (dermabrasion, cryotherapy, laser therapy, and surgical excision with ophthalmoplastic reconstruction) is rarely medically indicated due to the low risk of malignant transformation. Removal can be performed in cases of secondary amblyopia in ptosis, compression of the lacrimal point, epiphora, or cosmetic desire. Treatment becomes necessary not only in case of suspicious manifestation or impairment of eyelid function, but it also helps to avoid possible bullying at school among children and is recommended at age4 to6 (before school age).

Updates in the Management of Congenital Melanocytic Nevi.

Congenital melanocytic nevi (CMN) carry an increased risk of melanoma and may be disfiguring, and consensus regarding treatment recommendations is lacking. While clinical monitoring is the standard of care, many caregivers are interested in its removal to prevent psychosocial burden or to decrease risk. Although melanoma can occur regardless of CMN removal, there are a variety of treatments that may offer improved cosmesis or local symptom control, including surgical excision, laser therapy, and other superficially destructive techniques. Regardless of the selected management, these patients are monitored for ongoing melanoma risk. An extensive discussion with families regarding the risks and benefits of observation versus active intervention is essential. To facilitate these discussions, we herein summarize current CMN management strategies and considerations.

Giant Congenital Melanocytic Nevi: A Case Report in Madinah, Saudi Arabia

Giant congenital melanocytic nevi (GCMN) is an uncommon disorder that impacts newborns, with a prevalence of less than 1 in 20,000 births. Even though it is uncommon, detecting the condition early is essential because of the higher chance of complications such as malignant melanoma, central nervous system involvement, and negative effects on the patient and their family's mental well-being due to its unattractive appearance. A giant congenital melanocytic nevus (GCMN) is described as a dark brown skin lesion acquired at birth that has the potential to grow to over 40 cm in size as a person reaches adulthood. The diagnosis of the GCMN is clinically confirmed, while management is mainly symptomatic. Nevertheless, treatment options could consist of surgical and non-surgical methods, psychological therapy, and/or regular clinical monitoring, taking into account alterations in color, size, texture, or the area of the lesion. We describe here a case of GCMN in a male neonate observed in our practice. The patient presented with a huge, pigmented patch over the body since birth, encompassing the entire abdomen, extending to the chest, thighs, and genitalia with multiple satellite, a few lesions on the face, and laterally towards the posterior aspect of the trunk, involving the entire back and buttocks. Radiological investigations were performed and were reported as normal with no significant findings. Additionally, the MRI also did not indicate any involvement of the central nervous system; hence, multidisciplinary comprehensive care was followed for this neonate with monthly regular follow-ups at dermatology and pediatric clinics. Our case significantly highlights the observatory interdisciplinary management of this condition; however, if needed in the future, surgical intervention maybe considered to decrease the risk of malignancy.

An Atlas of Lumps and Bumps, Part 41: Congenital Melanocytic Nevi

An Atlas of Lumps and Bumps, Part 41: Congenital Melanocytic Nevi

A comparative study of deep learning algorithms for image-based classification of hyperpigmented skin disease

There are growing numbers of significant skin disorders, including skin pigmentation. It states that skin color is determined by the amount of melanin produced by the body. The two main categories of skin pigmentation are hyperpigmentation, in which pigment seems to overflow, and hypopigmentation, in which pigment appears to decrease. However, many skin conditions share characteristics, making it difficult for dermatologists to correctly early diagnose their patients. Consequently, the accurate detection of skin disorders and the diagnosis of dermatoscopy pictures can be greatly aided by machine learning and deep learning approaches. The most effective deep learning technique for picture identification was investigated to diagnose hyperpigmented skin diseases. YOLO, DenseNet201, GoogLeNet, InceptionResNetV2, and MobileNet were among the pretrained models used to classify four most common hyperpigmented skin disorders. Using assessment metrics like accuracy and AUC (Area Under Curve), it was determined which deep learning method would work best for creating a clinical diagnostic system. The study analyzed the accuracy rates of five pretrained models, including GoogleNet, MobileNet, DenseNet201, InceptionResNetV2, and YOLO, after 50 iterations. Using metrics such as accuracy and Area Under the Curve (AUC), the study evaluated the models' performance on a small dataset split into 80% for training and 20% for testing. Training accuracy rates were 93.8%, 100%, 100%, 98.77%, and 97.43%, respectively, while test accuracy rates were 87.18%, 79.49%, 87.18%, 89.74%, and 97.56%. DenseNet201 showed strong performance, particularly for cafe-au-lait spots (CS), melasma (ML), and nevi (MN), but struggled with congenital nevus (CN). Despite DenseNet201′s strong traditional CNN capabilities and generalization, YOLO emerged as the top model due to its stable accuracy and AUC values, as confirmed by confusion matrices. While these models show promise as diagnostic tools for dermatologists, further research, including expanding the dataset and exploring hybrid models, is needed to enhance their clinical accuracy and effectiveness.