Congenital melanocytic nevi: where are we now? Part I. Clinical presentation, epidemiology, pathogenesis, histology, malignant transformation, and neurocutaneous melanosis

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

BACKGROUND

Limited research exists on laser treatment of giant congenital melanocytic nevus (GCMN).

OBJECTIVE

We sought to elucidate the efficacy of the Erbium: YAG laser on GCMN and the histologic factors associated with a positive clinical response.

METHODS AND MATERIALS

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.

RESULTS

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).

CONCLUSION

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

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.

A clinical and biologic review of congenital melanocytic nevi

Congenital melanocytic nevi (CMN) are the result of aberrations in the mitogen-activated protein kinase signal transduction pathway caused by postzygotic somatic mutations. The estimated incidence of newborns with CMN is 1%-2%. The main complications of CMN include proliferative nodules, melanomas, and neurocutaneous melanosis, and the latter two are the most troublesome issues to address. Treatments are primarily taken into account for aesthetic purposes and the reduction of melanoma risk. Due to the much lower incidence of malignant transformation observed in recent studies than in previous data, clinical management paradigms for CMN patients have gradually shifted towards conservative observation and close monitoring. Surgery and lasers are still the main treatments, and targeted therapy may be a promising strategy to help manage complications. With the increase in awareness of mental health, increasing focus has been placed on the quality of life (QoL) and psychological issues of both CMN patients and their parents. Recent studies have revealed that families coping with CMN might endure intense pressure, a major loss in QoL, and psychological problems after diagnosis and during treatment. Here, we sought to present an overview of genetic basis, complications, treatments, and psychological issues related to CMN and hope to provide better management for patients with CMN.

Treatments of palpebral congenital melanocytic nevus: a systematic review

PURPOSE

Palpebral congenital melanocytic nevi (PCMN) is a rare congenital skin lesion affecting the eyelids that can lead to cosmetic and psychological concerns and potential health risks such as malignancy. Several authors have analyzed therapeutical strategies to treat PCMN. However, there was no consensus in the literature. This systematic review aimed to evaluate the effectiveness, safety, and success of treatments of PCMN.

METHODS

We conducted a systematic review following PRISMA guidelines from October 2022 to April 2023. We included all types of study designs that described or compared PCMN treatments and interventions, as well as histology, recurrence, adverse events, patient satisfaction, and malignant transformation. The search strategy was based on specific search words through the following databases: PubMed, Embase, Latin American and Caribbean Health Sciences Literature (Lilacs), Web of Science, and Scopus. Ongoing studies and gray literature studies were included.

RESULTS

We analyzed 25 case reports with 148 participants. The effectiveness, success, and satisfaction with various treatments for PCMN depend on the specific treatment method and the individual patient's case.

CONCLUSIONS

Most of the studies showed that surgical procedures (exeresis) are able to treat PCMN in the eyelid. The variability in outcomes emphasizes the importance of further research to better understand the most effective and safe approaches for treating congenital melanocytic nevi.

[Surgical treatment of nevi in children in a dermatological surgery center : Histopathology and complications]

BACKGROUND

The indication for surgical management and histological diagnosis of melanocytic nevi in children is a major challenge in clinical routine. In consultations with children and parents, the exclusion of malignant findings, on the one hand, and the risk of complications, on the other hand, are important.

PATIENTS AND METHODOLOGY

Included were 946 children under the age of 10 years who underwent surgery with a suspected diagnosis of melanocytic nevus at the University Department of Dermatology, Tübingen, Germany, between 2008 and 2018. Dermatohistopathologic findings and postoperative complications were recorded.

RESULTS

A clinical diagnosis of melanocytic nevus was histologically confirmed in 93.2% (882/946) of cases, whereby there were 41 Spitz nevi and 18 pigmented spindle cell tumors. Melanoma was diagnosed in 2 of the children (0.2%). In another 6.6%, non-melanocytic findings (e.g., nevus sebaceous, epidermal nevi) were diagnosed. The complication rate was low at 3%. The most common complication was the occurrence of postoperative wound infection in 1.7%.

CONCLUSION

It is possible to take a biopsy or surgically remove congenital nevi of different sizes even in infants. Serial excision of congenital nevi is an important tool for this purpose. In the investigated cohort, the complication rate was low. Histological confirmation is essential in case of clinically suspicious or atypical findings.

Central nervous system magnetic resonance imaging abnormalities and neurologic outcomes in pediatric patients with congenital nevi: A 10-year multi-institutional retrospective study

BACKGROUND

High-risk congenital melanocytic nevi (CMN) are associated with abnormalities of the central nervous system (CNS), prompting magnetic resonance imaging (MRI) screening guidelines.

OBJECTIVE

Describe MRI brain and spine abnormalities in children with CMN and report trends between nevus features, MRI findings, and neurologic outcomes.

METHODS

Retrospective review of individuals aged ≤18 years with an MRI of the brain and/or spine and at least 1 dermatologist-diagnosed CMN.

RESULTS

Three hundred fifty-two patients were identified. Forty-six children had CMN that prompted an MRI of the brain and/or spine (50% male, average age at first image, 354.8 days). In these children, 8 (17%) had melanin detected in the CNS, of whom all had >4 CMN. One developed brain melanoma (fatal). In patients without CNS melanin, 4 had concerning imaging. Concerning MRI patients had more neurodevelopmental problems, seizures, neurosurgery, and death than individuals with unremarkable imaging. Three hundred six patients received MRIs for other reasons; none detected melanin. No children with only multiple small CMN (n = 15) had concerning imaging.

LIMITATIONS

Lack of a control group, cohort size, and retrospective methods.

CONCLUSION

MRI of the brain and spine is useful for detecting intervenable abnormalities in high-risk children. Healthy infants with few small CMN may not require screening MRI.

Comparison of three different surgical approaches for the treatment of large/giant congenital melanocytic nevus

OBJECTIVE

Treating large/giant congenital melanocytic nevus (L/GCMN) is challenging for surgeons. Operative approaches commonly used to remove L/GCMN include serial excision, tissue expansion, and skin grafting. Thus, we retrospectively compared these three operations' applications and therapeutic effects.

METHODS

The clinical data of 97 L/GCMN patients from June 1, 2015, to June 1, 2019, were collected and divided into three groups according to the operations used: serial excision group(SE group, n=18), tissue expansion group(TE group, n=23) and skin grafting group(SG group, n=56). The location and size of the lesion, the number of operations, duration of each operation, preoperative preparation time, postoperative hospital stay, complications, and clinical outcomes of all patients were collected and assessed.

RESULTS

The SE group had the most times of operation (3.9 and 6.0 for LCMN and GCMN, respectively), the shortest surgery length (56.3min), and the shortest postoperative hospital stay (10.0d). The SE and SG groups required much less time to prepare for surgery and had a lower rate of complications than the TE group. During the 11.9-month median follow-up period, the SE and TE groups had better postoperative outcomes than the SG group.

CONCLUSION

Each of the three operations has different advantages and disadvantages, and the specific surgical strategy should be decided based on the patient's unique circumstances.

Dufourmentel Flap for Surgical Treatment of Medium-sized Congenital Melanocytic Nevi on the Extremities

Congenital melanocytic nevi (CMN) are quite common benign proliferations of cutaneous melanocytes. They are present at birth or arise during the first few weeks of life being upper and lower extremities one of the most common locations. To date consistent guidelines for clinical management of CMN do not yet exist and the main reasons for removing them are medical and cosmetic. Regardless of the cause of having a CMN removed, when it comes to surgical excision of the lesion in daily practice the single most important decision to make is how to properly close the post-excisional defect. The local Dufourmentel skin flap seems to be a reliable solution for surgical treatment of medium-sized CMN on the limbs. It takes advantage of skin laxity adjаcent to thе defect to allоw the transpositiоn of tissuе with similаr charactеristics tо the tissuе еxcisеd which is the key for achieving good aesthetic and functional outcomes. In this brief clinical study the author identified a group of adult patients who had medium-sized CMN located on their extremities. The surgical technique is explained and useful tips are given. No complications and high patient satisfaction rate were registered in the series. Dufourmentel flap is a useful tool in the armamentarium of dermatologic surgery when dealing with medium-sized CMN on the extremities. Furthermore, due to its versatility this flap could also be applied for other clinical indications both benign and malignant.

Neonatal Curettage of Large to Giant Congenital Melanocytic Nevi Under Local Anesthetic: A Case Series With Long-Term Follow Up

Background

Neonatal curettage of large to giant congenital melanocytic nevi (L-GCMN) is a simple, minimally invasive procedure typically performed within the first 2 weeks of life.

Objectives

To retrospectively review our experience with serial curettage of L-GCMN in the neonatal period performed under local anesthesia and their long-term outcomes.

Methods

Curettage was performed by a single pediatric dermatologist on nine neonates with L-GCMN under local anesthetic and with oral analgesia between 2002 and 2016 in Red Deer, Alberta, Canada. Patient charts were reviewed retrospectively to assess patient and procedure characteristics, tolerability, safety, cosmetic and functional outcomes, and malignant transformation.

Results

Patients were treated with an average of 6 curettage sessions (range 3 to 15) to remove the majority or entirety of the nevus. All patients tolerated local anesthesia well. The most common adverse event of the procedure was transient neutropenia. Two patients developed positive bacterial cultures without clinical signs of infection, treated with antibiotics. All curetted specimens demonstrated benign pathology. Patients were followed annually thereafter, for an average of 6 years. Eight patients with L-GCMN of the trunk had minimal to partial repigmentation with good cosmetic outcome. One patient had recurrence of a facial nevus. None of the patients developed cutaneous malignant melanoma.

Conclusions

Curettage appears to be a safe and effective treatment option for select cases of L-GCMNs of the trunk. We do not recommend the procedure for face or scalp CMN. This procedure can be performed under local anesthesia with serial curettage to avoid potential risks of general anesthesia.

[An adult case of neurocutaneous melanosis with acute exacerbation after a long asymptomatic period following excision of a melanocytic nevus]

Neurocutaneous melanosis is caused by postzygotic NRAS mutations in neural crest cells, resulting in large or multiple nevi in the skin and proliferation of leptomeningeal melanocytes in the central nervous system. The onset of neurological symptoms is usually before the age of 2 years, but it can also occur in adults. A 35-year-old male had been asymptomatic for a long time after excision of a large congenital melanocytic nevus, but he developed headache, disturbance of consciousness, and seizure. Methotrexate was ineffective, cerebral pressure was decreased by spinal drainage, and steroid pulse therapy was temporarily effective. Seizures and disturbance of consciousness worsened and the patient died on the 92nd day. Cerebrospinal fluid human melanin black-45 immunostaining and serum 5-S-cysteinyldopa (5-S-CD) were useful in diagnosing melanocytic proliferation, and serum 5-S-CD may be useful in predicting prognosis.

Imaging and clinical features of neurocutaneous melanosis in the pediatric population

BACKGROUND

Neurocutaneous melanosis (NCM) is a rare nonfamilial phakomatosis characterized by the presence of congenital melanocytic nevi and abnormal melanocytes infiltration of the leptomeninges.

OBJECTIVE & METHODS

This paper shows the importance of early diagnosis and the most important imaging features of the disease on CT and MR scans. PubMed database was searched from January 1972 to September 2020. Papers including imaging findings of NCM, clinical, follow-up, and treatment features were collected, selecting only 89 studies.

DISCUSSION

NCM is a term used for the first time by van Bogaert in 1948. It refers to a condition caused by an error during morphogenesis and migration leading to leptomeningeal melanocytic accumulation. Although histological findings are the gold standard for diagnosis confirmation, neuroimaging and clinical features strongly support the suspect of NCM. Localization and extension of the lesions are predictive of neurological manifestations related to increased intracranial pressure, mass lesions, or spinal cord compression. CT demonstrates sites of increased density in the anterior temporal lobe - mainly the amygdala - thalami, cerebellum, and frontal lobes base. However, MRI is the best imaging method to diagnose central nervous system lesions, often appearing as T1-short signal areas of the cerebral parenchyma, indicative of central nervous system melanosis. MRI can also reveal associated intracranial and intraspinal abnormalities.

CONCLUSION

Early imaging, when available, is helpful if NCM suspect is raised and may be of guidance in comparing later studies. NCM requires a multidisciplinary approach since it is a multisystem disease with a genetic component.

Giant cerebriform melanocytic nevus of the scalp: A case report

Giant melanocytic nevus is a rare condition caused by benign proliferation of melanocytes. There is a slight risk of malignancy in these lesions which should be noticed especially when they become larger. GCMN can be removed by plastic surgery.

Treatment of giant congenital melanocytic nevi with cultured epithelial autografts: Clinical and histopathological analysis

Introduction

Curettage and dermabrasion are effective in the treatment of giant congenital melanocytic nevi (GCMN); however, local infection and hypertrophic scar formation are major issues. Thus, we applied cultured epithelial autografts (CEA) on skin defects after curettage or abrasion of GCMN and assessed the postoperative outcomes.

Methods

Seven nevi lesions of five patients (aged 3 months to 24 years) were treated with CEA after curettage or abrasion with a dermatome or a surgical bar, respectively. We assessed the postoperative outcomes, including CEA take ratio, erosion and/or ulcer formation in the acute phase, hospitalization days, Vancouver scar scale, and color improvement one year after the operation. In addition, a histological evaluation of a skin biopsy was performed over one year after the operation.

Results

The CEAs took well on the wound, and the wound surface was mostly epithelized by postoperative day 7 in all cases. While hypertrophic scar formation and slight pigmentation were observed in some lesions, the color was improved in all of the treated lesions. Histopathological examination revealed that the regenerated epidermis had stratified keratinocytes with rete ridges, and the dermal layer without nevus cells regenerated above the remaining dermis layer.

Conclusions

In this study, we found that early epithelialization and regeneration of the dermal layer was achieved after the application of CEA, suggesting that CEA could be an effective option after curettage or abrasion of GCMN.

•

Cultured epithelial autograft (CEA) application is effective in the treatment of giant congenital melanocytic nevi.

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The grafted CEA takes well on skin defects post curettage and abrasion.

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CEAs can achieve rapid epithelization.

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Normal dermal tissue regenerates after CEA application.

Concepts Important to Patients With Facial Differences: A Qualitative Study Informing a New Module of the FACE-Q for Children and Young Adults

Objective:

The concepts important to children and young adults who undergo treatments for facial differences are not well-defined. Measurement of treatment outcomes from the patient’s perspective is necessary to ensure goals of treatment are met. We aimed to identify concepts important to children and young adults with facial differences through a qualitative study.

Design:

An interpretive description qualitative approach was followed. Semistructured interviews were conducted, transcribed verbatim, and coded using a line-by-line approach. Qualitative analysis led to the development of a conceptual framework of outcomes important to patients.

Setting:

Interviews were conducted in Canada and the United Kingdom at home, by telephone, or in the hospital.

Participants:

Participants (N = 72) were recruited between May and June 2014 from craniofacial clinics at the Hospital for Sick Children (Toronto) and Great Ormond Street Hospital (London). Participants included anyone with a visible and/or functional facial difference aged 8 to 29 years and fluent in English, excluding patients with a cleft. The sample included 38 females and 34 males, with a mean age of 13.9 years, and included 28 facial conditions (11 facial paralysis, 18 ear anomalies, 26 skeletal conditions, and 17 soft tissue conditions).

Results:

Analysis led to identification of important concepts within 4 overarching domains: facial appearance, facial function, adverse effects of treatment, and health-related quality of life (psychological, social, and school function).

Conclusions:

Our study provides an understanding of concepts important to children and young adults with facial differences.

Neurocutaneous melanocytosis (melanosis)

Neurocutaneous melanosis (NCM; MIM # 249400; ORPHA: 2481], first reported by the Bohemian pathologist Rokitansky in 1861, and now more precisely defined as neurocutaneous melanocytosis, is a rare, congenital syndrome characterised by the association of (1) congenital melanocytic nevi (CMN) of the skin with overlying hypertrichosis, presenting as (a) large (LCMN) or giant and/or multiple (MCMN) melanocytic lesions (or both; sometimes associated with smaller "satellite" nevi) or (b) as proliferative melanocytic nodules; and (2) melanocytosis (with infiltration) of the brain parenchyma and/or leptomeninges. CMN of the skin and leptomeningeal/nervous system infiltration are usually benign, more rarely may progress to melanoma or non-malignant melanosis of the brain. Approximately 12% of individuals with LCMN will develop NCM: wide extension and/or dorsal axial distribution of LCMN increases the risk of NCM. The CMN are recognised at birth and are distributed over the skin according to 6 or more patterns (6B patterns) in line with the archetypical patterns of distribution of mosaic skin disorders. Neurological manifestations can appear acutely in infancy, or more frequently later in childhood or adult life, and include signs/symptoms of intracranial hypertension, seizures/epilepsy, cranial nerve palsies, motor/sensory deficits, cognitive/behavioural abnormalities, sleep cycle anomalies, and eventually neurological deterioration. NMC patients may be symptomatic or asymptomatic, with or without evidence of the typical nervous system changes at MRI. Associated brain and spinal cord malformations include the Dandy-Walker malformation (DWM) complex, hemimegalencephaly, cortical dysplasia, arachnoid cysts, Chiari I and II malformations, syringomyelia, meningoceles, occult spinal dysraphism, and CNS lipoma/lipomatosis. There is no systemic involvement, or only rarely. Pathogenically, single postzygotic mutations in the NRAS (neuroblastoma RAS viral oncogene homologue; MIM # 164790; at 1p13.2) proto-oncogene explain the occurrence of single/multiple CMNs and melanocytic and non-melanocytic nervous system lesions in NCM: these disrupt the RAS/ERK/mTOR/PI3K/akt pathways. Diagnostic/surveillance work-ups require physical examination, ophthalmoscopy, brain/spinal cord magnetic resonance imaging (MRI) and angiography (MRA), positron emission tomography (PET), and video-EEG and IQ testing. Treatment strategies include laser therapy, chemical peeling, dermabrasion, and surgical removal/grafting for CMNs and shunt surgery and surgical removal/chemo/radiotherapy for CNS lesions. Biologically targeted therapies tailored (a) BRAF/MEK in NCM mice (MEK162) and GCMN (trametinib); (b) PI3K/mTOR (omipalisib/GSK2126458) in NMC cells; (c) RAS/MEK (vemurafenib and trametinib) in LCMNs cells; or created experimental NMC cells (YP-MEL).

Novel genetic alteration in congenital melanocytic nevus: MAP2K1 germline mutation with BRAF somatic mutation

Congenital melanocytic nevus (CMN) represent a benign proliferative skin disease in the epidermis and dermis. CMN are historically known to be associated with activating NRAS or BRAF mutations. Melanoma frequently harbors the BRAF p.Val600Glu mutation, which is also commonly found in benign nevi. A recent study reported mutation of MAP2K1, a downstream effector of the RAS-RAF-MEK pathway, in melanoma with an overall frequency of 8%. Later, in 2019, Jansen P detected one activating MAP2K1 mutation in acral nevi. However, it is unknown whether MAP2K1 mutations are common in CMN, and how MAP2K1 contributes to the pathogenesis of CMN remains to be determined.In this study, we report one patient clinically and histologically diagnosed with CMN, with the MAP2K1 germline mutation and a BRAF p.Val600Glu somatic hit in the lesion. To the best of our knowledge, this is the first report of the coexistence of mutated BRAF and MAP2K1 in CMN, which may suggest that MAP2K1 mutations contribute to the occurrence and development of nevus expanding our knowledge of the genetics of CMN.

Melanocortin-1 receptor (MC1R) genotypes do not correlate with size in two cohorts of medium-to-giant congenital melanocytic nevi

Congenital melanocytic nevi (CMN) are cutaneous malformations whose prevalence is inversely correlated with projected adult size. CMN are caused by somatic mutations, but epidemiological studies suggest that germline genetic factors may influence CMN development. In CMN patients from the U.K., genetic variants in MC1R, such as p.V92M and loss-of-function variants, have been previously associated with larger CMN. We analyzed the association of MC1R variants with CMN characteristics in two distinct cohorts of medium-to-giant CMN patients from Spain (N = 113) and from France, Norway, Canada, and the United States (N = 53), similar at the clinical and phenotypical level except for the number of nevi per patient. We found that the p.V92M or loss-of-function MC1R variants either alone or in combination did not correlate with CMN size, in contrast to the U.K. CMN patients. An additional case-control analysis with 259 unaffected Spanish individuals showed a higher frequency of MC1R compound heterozygous or homozygous variant genotypes in Spanish CMN patients compared to the control population (15.9% vs. 9.3%; p = .075). Altogether, this study suggests that MC1R variants are not associated with CMN size in these non-UK cohorts. Additional studies are required to define the potential role of MC1R as a risk factor in CMN development.

Giant congenital melanocytic nevus of the scalp: from clinical-histological to molecular diagnosis

Congenital melanocytic nevus (CMN) is a benign proliferative skin disease in the epidermis and dermis. Large to giant CMNs are estimated to be associated with an increased lifetime risk of malignancy. It is necessary to estimate and monitor the risk of malignant transformation for giant CMNs. To date, the clinical “ABCD” criteria and immunohistochemistry studies can be confusing and, to some extent, subjective. Accordingly, the elucidation of genomic analyses of nevi is required to better understand the malignant transformation of CMNs. Here, we describe two large to giant CMNs of the scalp with opposite clinical-histological and molecular evaluations of potential malignancy risk. To our knowledge, this is the first description of a genetic study of large to giant CMNs of the scalp in East Asia. We recommend reviewing the molecular diagnosis together with careful medical history and histological information to facilitate the evaluation of the potential malignancy risk.

Surgical treatment of children and youth with congenital melanocytic nevi: self- and proxy-reported opinions

PURPOSE

The role of surgery in the management of congenital melanocytic nevi (CMN) is controversial. Data on surgical outcomes and predictors of satisfaction remain scarce.

METHODS

An online survey was employed following worldwide recruitment of youth aged 14-25 years (n = 44) and parents of children ≤ 18 years (n = 249) with CMN to query patterns of treatment and satisfaction with and opinions about the benefits of surgery.

RESULTS

In proxy-reports, 121 of 249 (49%) and in self-reports 30 of 44 (75%) participants underwent CMN excision. The most common reasons for surgery were psychosocial determinants, aesthetic improvement, and melanoma risk reduction. The overall satisfaction with surgical management was good, although no predictors for satisfaction could be identified. Higher current age of the child was found to predict decision regret in proxy-reports. Most participants indicated that having a scar is more socially acceptable than a CMN. Opinions differed on whether surgery should be deferred until the child is old enough to be involved in the decision-making process.

CONCLUSIONS

Whether and when to perform surgery in children with CMN is a multifaceted question. Awareness of common concerns as well as risks and benefits of surgery are essential to ensure critical reflection and balanced decision-making.

Disorders Caused by Genetic Mosaicism

BACKGROUND

Genetic mosaics arise through new mutations occurring after fertiliza- tion (i.e., postzygotic mutations). Mosaics have been described in recent years as the cause of many different disorders; many of these are neurocutaneous diseases and syndromal developmental disorders, each with a characteristic phenotype. In some of these disorders, there is a genetic predisposition to the development of tumors. This article is intended as an overview of selected mosaic diseases.

METHODS

This review is based on publications retrieved by a selective search in PubMed, with particular attention to recent articles in high-ranking journals dealing with asymmetric growth disturbances, focal brain malformations, mosaic diseases due to dysregulation of the RAS/RAF signaling pathway (mosaic RASopathies), and vascular malformations.

RESULTS

The identification of postzygotic mutations has led to the reclassification of traditional disease entities and to a better understanding of their pathogenesis. Diagnosis is aided by modern next-generation sequencing (NGS) techniques that allow the detection even of low-grade mosaics. Many mosaic mutations are not detectable in blood, but only in the affected tissue, e.g., the skin. Genetic mosaic diseases often manifest themselves in the skin and brain, and by facial dysmorphism, asymmetrical growth disturbances, and vascular malformations.

CONCLUSION

The possibility of a mosaic disease should be kept in mind in the diag- nostic evaluation of patients with asymmetrical growth disturbances, focal neuronal migration disturbances, vascular malformations, and linear skin abnormalities. The demonstration of a postzygotic mutation often affords relief to the parents of an affected child, since this means that there is no increased risk for recurrence of the same disorder in future children. Correct classification is important, as molecular available for certain mosaic diseases, e.g., PIK3CA-related overgrowth spectrum (PROS) disorder.

A large-scale collection of giant congenital melanocytic nevi: Clinical and histopathological characteristics

Giant congenital melanocytic nevi (GCMN) place a heavy psychological burden on patients due to their poor cosmetic appearance. The histopathological characteristics of GCMN have remained largely elusive. The present study investigated the histopathological characteristics of GCMN in association with their clinical appearance. A total of 98 patients diagnosed with GCMN were included in the present study and their clinical features were collected from their records. Lesion specimens were obtained and stained for histopathological analysis. Regarding the microscopic appearance of GCMN, nevi cells in the whole dermis exhibited different patterns than those in healthy tissues. Most GCMN cases featured a sub-epidermal non-involvement zone, which implies an early occurrence in embryo development. Darker nevi exhibited a higher density of infiltrated nevi cells and more pigment deposition; this appears to induce a poor skin texture. Chemical peeling and laser therapy only partly removes pigment particles and nevi cells in the upper portion of the dermis. The clinical features of GCMN are associated with the histopathological characteristics, and non-surgical therapy cannot remove the nevus cells in the deep dermis.

Acral melanocytic nevi in the Polish population: prevalence, clinical characteristics and dermoscopic patterns

Introduction

Acral melanocytic nevi dermoscopic patterns have been well described in several populations. There have been no prospective studies assessing the prevalence, clinical characteristics and dermoscopic patterns of acral nevi in the Polish population.

Aim

To characterize the prevalence of acral nevi, frequency of dermoscopic patterns, relationships between acral nevi and patients’ characteristics.

Material and methods

This was a prospective study conducted in the Dermatological Outpatient Clinic of the University Hospital in Krakow. Study inclusion criteria: presence of nevi on foot soles and/or palms, Caucasian race, Polish origin, and age ≥ 18 years.

Results

Six hundred and twenty-four acral melanocytic lesions were observed in 287 patients, 174 (60.6%) women and 113 (39.4%) men, mean age 43.5 and 42.8 years, respectively. Four hundred and thirty-four (69.6%) lesions were present on soles, 190 (30.4%) on palms. No acral melanomas were detected. The following dermoscopic patterns were observed: parallel furrow 262 (42%), lattice-like 106 (17%), fibrillar 66 (11%) and other 190 (30%). Patients with acral nevi on the soles or both on the palms and soles had a higher number of atypical nevi on the body (p = 0.011) and a much higher total body nevi count (p = 0.043), when compared to those with acral nevi only on the palms.

Conclusions

The study revealed a higher prevalence of acral nevi in the analysed population. A higher number of acral nevi was associated with a higher number of atypical nevi and higher total body nevi count, the risk factors for melanoma. Because of that it is possible to note that a higher number of acral nevi should increase diagnostic alertness.

Melanom

Das Melanom ist der gefährlichste Hautkrebs mit der höchsten Sterblichkeitsrate, der schon bei jungen Menschen auftreten kann und seit Jahrzehnten steigende Inzidenz verzeichnet (Jemal et al. 2007; Little et al. 2012). Jährlich erkranken weltweit etwa 137.000 Menschen am Melanom und 37.000 versterben an der Erkrankung (Boyle et al. 2004). Die Inzidenz liegt weltweit jährlich bei 2,3–2,6/100.000 Einwohner (Pisani et al. 2002). In Deutschland beträgt die Inzidenz 19,2/100.000 Einwohner und es verstarben 2711 Betroffene im Jahre 2010 (Statistisches Bundesamt).

Common Neonatal Skin Lesions: Melanocytic Nevi, Pigment Alterations, and Nonmelanocytic Nevi

Birthmarks are common in the healthy population and are generally harmless. Certain presentations, however, raise concern for associated syndromes or potential complications. It is important for pediatricians to be familiar with both harmless and potentially concerning birthmarks. This article discusses congenital melanocytic nevi, café-au-lait macules, hypomelanotic macules, nevus depigmentosus, nevus anemicus, epidermal nevi, and nevus sebaceous, including potential syndromes and complications. [Pediatr Ann. 2019;48(1):e23-e29.].

MelaNostrum: a consensus questionnaire of standardized epidemiologic and clinical variables for melanoma risk assessment by the melanostrum consortium

BACKGROUND

Many melanoma observational studies have been carried out across different countries and geographic areas using heterogeneous assessments of epidemiologic risk factors and clinical variables.

AIM

To develop a consensus questionnaire to standardize epidemiologic and clinical data collection for melanoma risk assessment.

METHODS

We used a stepwise strategy that included: compilation of variables from case-control datasets collected at various centres of the MelaNostrum Consortium; integration of variables from published case-control studies; consensus discussion of the collected items by MelaNostrum members; revision by independent experts; addition of online tools and image-based charts; questionnaire testing across centres and generation of a final draft.

RESULTS

We developed a core consensus questionnaire (MelanoQ) that includes four separate sections: A. general and demographic data; B. phenotypic and ultraviolet radiation exposure risk factors and lifestyle habits; C. clinical examination, medical and family history; and D. diagnostic data on melanoma (cases only). Accompanying online tools, informative tables, and image-based charts aid standardization. Different subsections of the questionnaire are designed for self-administration, patient interviews performed by a physician or study nurse, and data collection from medical records.

CONCLUSIONS

The MelanoQ questionnaire is a useful tool for the collection and standardization of epidemiologic and clinical data across different studies, centres, cultures and languages. This will expedite ongoing efforts to compile high-quality data for pooled analyses or meta-analyses and offer a solid base for the design of clinical, epidemiologic and translational studies on melanoma.

Common and not so Common Melanocytic Lesions in Children and Adolescents

The acquired melanocytic nevus is the most common lesion encountered by pediatric pathologists and dermatopathologists in their daily practice. In most cases, there are few difficulties in histopathologic diagnosis. However, it is the acquired melanocytic lesion known as the Spitz nevus, with its intrinsic atypical features which becomes the challenge since it exists along a histopathologic and biologic continuum from the atypical Spitz tumor to spitzoid melanoma. The frustration with some of these spitzoid lesions is that even the "experts" cannot agree as to the differentiation of one from the other even at the level of molecular genetics. Other melanocytic lesions are discussed including the congenital melanocytic nevus with its proliferative nodule(s) and melanoma as the ultimate complication. Although uncommon, cutaneous melanoma in the first 2 decades is emerging as a clinical problem especially in young women in the second decade of life. These are ultraviolet-associated neoplasms whose histopathologic and prognostic features are identical to the adult experience. Considerable progress has been made over the past 15 to 20 years in our understanding of cutaneous melanocytic lesions, but gaps still exist in the important group of spitzoid lesions. It can also be anticipated that more cutaneous melanomas in children will be seen in the future based upon epidemiologic studies.

Content Validity of Patient-Reported Outcome Instruments used with Pediatric Patients with Facial Differences

Objective:

The aim of this systematic review was to identify patient-reported outcome (PRO) instruments used in research with children/youth with conditions associated with facial differences to identify the health concepts measured.

Design:

MEDLINE, EMBASE, CINAHL, and PsycINFO were searched from 2004 to 2016 to identify PRO instruments used in acne vulgaris, birthmarks, burns, ear anomalies, facial asymmetries, and facial paralysis patients. We performed a content analysis whereby the items were coded to identify concepts and categorized as positive or negative content or phrasing.

Results:

A total of 7,835 articles were screened; 6 generic and 11 condition-specific PRO instruments were used in 96 publications. Condition-specific instruments were for acne (four), oral health (two), dermatology (one), facial asymmetries (two), microtia (one), and burns (one). The PRO instruments provided 554 items (295 generic; 259 condition specific) that were sorted into 4 domains, 11 subdomains, and 91 health concepts. The most common domain was psychological (n = 224 items). Of the identified items, 76% had negative content or phrasing (e.g., “Because of the way my face looks I wish I had never been born”). Given the small number of items measuring facial appearance (n = 19) and function (n = 22), the PRO instruments reviewed lacked content validity for patients whose condition impacted facial function and/or appearance.

Conclusions:

Treatments can change facial appearance and function. This review draws attention to a problem with content validity in existing PRO instruments. Our team is now developing a new PRO instrument called FACE-Q Kids to address this problem.

One Step Melanoma Surgery for Patient with Thick Primary Melanomas: "To Break the Rules, You Must First Master Them!"

BACKGROUND:

We present to the attention of the medical, dermatological and oncosurgical community data that serves to indicate the indispensability of optimisation of the algorithm and recommendations for diagnosis and surgical treatment of cutaneous melanoma. These recommendations could be referred to different subgroups of patients in different clinical stages as well as to patients with different initial characterisation (histological morphology) of the primary tumours. One step surgery is not a myth, even more, it could prove to be one of the best solutions for some patient collectives with advanced stages of melanoma.

CASE REPORT:

We present a case of a 74 - year old patient with a congenital medium sized melanocytic nevus, located directly above the lateral part of the elbow joint. In one month and a half, an achromatic nodular formation evolves with a diameter of 2.7 x 2.3 cm, prominent over the skin level, painful by palpation and spontaneously bleeding. By the anamnestic, clinical and dermoscopic findings the patient was diagnosed with nodular melanoma associated with a congenital medium sized melanocytic nevus. A primary excision with a field of safety 0.5 cm in all directions was performed. After confirmation of the primary diagnosis (tumour thickness 8 mm with no ultrasonographic detection of enlarged lymph nodes), seven days later are - excision was performed with an additional field of surgical safety of 1.5 cm in all directions.

CONCLUSIONS:

In this case remains unclear the following question: For what reason a preoperative high - frequent ultrasonography (HFUS) is not recommended to be used as it will allow only one surgical excision with the elimination of a tumour with a safety field of 2cm in all directions? The enigma about the obstacles preventing such a rational optimisation of the current diagnostic and therapeutic algorithm in patients with melanomas remains unresolved. One step surgery for cutaneous melanoma is widely used in many countries although it continues to be considered as a matter of dispute for some experts. Once again, by a clinical case and the following analysis, we would like to focus the attention of the dermatosurgical community on this crucial and highly significant problem. Innovations are very often resulting from the simplicity of logic, which unfortunately is not always accepted appropriately.

The spectrum of skin biopsies and excisions in a pediatric skin center

Little is known about the spectrum of pediatric skin disorders requiring biopsy/excision, their indication, impact on further management, and the accuracy of clinical diagnosis. We aimed to address these questions in the patient population seen at our Swiss University referral center for Pediatric Dermatology and Plastic Surgery. All skin biopsies/excisions performed in patients aged ≤ 16 years over a period of 2 years were retrospectively analyzed. A total of 506 samples were included. The majority of biopsies/excisions (n = 413, 82%) was performed for tumors, cysts, and hamartomas and 18% for other skin conditions. Malignant tumors were found in 12 samples (2%) from four patients. In 121 (24%) patients, the histopathology had an important impact on patient management. In 80 (16%) cases, the pathology did not match with the clinical diagnosis. In 382 (75%) cases, excision was the treatment of choice. Of these, the indication for surgery was based on patient's request in 181 (47%) cases.

CONCLUSION

Surgical interventions for pediatric skin disorders are performed for diagnostic and therapeutic reasons. In this cohort, histopathology was essential for treatment in one quarter of cases. Skin tumors, cysts, and hamartomas often require excision during childhood, with families' request and esthetic considerations playing an important role. What is Known: • The spectrum of pediatric skin conditions has been studied in outpatient, inpatient, and emergency settings. • In contrast, no data exist on the spectrum of pediatric skin disorders undergoing biopsy/excision specifically. What is New: • We analyze biopsies/excisions in children, focusing on diagnosis, indication, and impact on patient management. • Surgical interventions for skin disorders in children are often performed for tumors and hamartomas with esthetic considerations playing a relevant role. If used for diagnostic purposes, they are often performed to confirm or rule out severe skin disease.

Congenital melanocytic nevus mimicking a turban tumour in an 18-year-old Filipino male

Congenital melanocytic nevi (CMN) are nevi that are present at birth or arise within the first few weeks of life. They are often found on the trunk, head and neck and extremities. We report herein an unusual presentation of a CMN as a cerebriform tumour presenting as secondary cutis verticis gyrata on the scalp of an 18-year-old Filipino male.

Stepwise, Multi-Incisional, and Single-Stage Approach to Reshape Facial Contour After Large Cutaneous Lesion Resection

BACKGROUND

Removal of large facial benign cutaneous lesions remains challenging. Serial or complete excisions together with local flaps or expander-based reconstructions are required. However, those techniques are time-consuming and may contribute to poor cosmetic and functional outcomes.

OBJECTIVE

The authors describe the resection and reconstruction of large facial benign cutaneous lesions by using Stepwise, Multi-Incisional, and Single-Stage (SMISS) approach.

METHODS

The authors performed a retrospective review from all patients with large facial benign cutaneous lesions who underwent "SMISS" approach for reconstruction between September 2013 and December 2014.

RESULTS

The authors treated 47 patients (32 female and 15 male; mean age 23.5 years, range 9-50 years). Follow-up was for 12 months or longer. The mean length of major axis was 43.91 mm, minor axis 32.10 mm, and scar 66.91 mm. Good to excellent outcomes were achieved in all patients with a mean Vancouver scar scale score of 3.46 ± 0.39 (Cronbach α = 0.890) and mean visual analog scale score of 8.02 ± 0.69 (Cronbach α = 0.946).

LIMITATIONS

This was a nonrandomized, unblinded clinical case series with a limited sample size.

CONCLUSION

For the excision and reconstruction of large facial benign cutaneous lesions, "SMISS" technique can be considered as a suitable option, leading to excellent results and a high patient satisfaction.

The High Multiplicity of Prenatal (Congenital Type) Nevi in Adolescents and Adults

In the absence of work on prenatal nevogenesis, it has long been necessary to define congenital melanocytic nevi by clinical detection on neonatal skin examination. They are seen in approximately 1% of newborns, with multiplicity in approximately 3% of cases. Melan-A staining of grossly normal fetal skin recently demonstrated fetal nevi, whose features validated certain traditional histologic criteria for "congenital type" nevi that may not have been detectable at birth. This suggested that many clinically acquired nevi actually formed in utero, like congenital nevi. Prenatal nevi has been suggested as a preferred synonym for "congenital type" nevi. Prenatal nevi were detected in 6 of 25 fetuses (24%), a strikingly higher incidence than congenital nevi in newborns. In this series of 354 patients with prenatal (congenital type) nevi encountered in routine practice at a community hospital, over 30% of both adolescents and adults had multiple prenatal nevi; a strikingly higher rate of multiplicity than congenital nevi in newborns. This high multiplicity may reflect origin beneath the epidermis, with many prenatal nevi working their way up to the surface of the skin decades after birth.

Treating Giant Congenital Nevus With Integra Dermal Regeneration Template in a 9-Year-Old Girl

Integra dermal regeneration template has been well established in treating deep extensive burns, but there are very few cases reported of treating large full-thickness skin defects such as giant nevi. Apart from psychological and cosmetic burdens, the giant congenital nevus carries increased risk of malignant alteration. We present the case of a 9-year-old girl with a giant congenital nevus on her left lower leg. A total excision was done and she was successfully treated with Integra (LifeSciences Corp, Plainsboro, NJ). Three weeks later, a thin split-skin graft was applied over the neodermal skin layer. The takeoff was 91%. Protected with the silver wound dressing, the rest of the wound healed. A donor site morbidity was minimal, and the final result was excellent both in aesthetic and functional aspects.

Dermoscopic Features of Small, Medium, and Large-Sized Congenital Melanocytic Nevi

BACKGROUND

Congenital melanocytic nevi (CMN) are present at birth. It is well known that the presence of large-sized congenital nevus in early life could predict a major risk of developing melanoma.

OBJECTIVE

To investigate the clinical and dermoscopic features of the CMN, to search for and highlight any differences between small-sized, medium-sized, large-sized CMN.

METHODS

A nonrandomized observational study was performed. A total of 108 melanocytic nevi were analysed by clinical and dermoscopic examination.

RESULTS

Of the subjects, 57.4% were aged less than 16 years, 42.6% were aged 16 and more. Of the nevi, 26 had reticular pattern (24.1%), 35 had globular pattern (32.4%), 13 had reticular-globular pattern (12.0%), 16 had homogeneous pattern (14.8%), 6 had reticular-homogeneous pattern (5.6%), 2 had globular-homogeneous pattern (1.9%), 7 had cobblestone pattern (6.5%), 3 had reticular patchy pattern (2.8%). Atypical dots and globules, focal hypopigmentation and perifollicular hypopigmentation are the most common dermoscopic features of CMN. The rarest dermoscopic feature is the blue-whitish veil.

CONCLUSION

Most of the dermoscopic features related with dysplastic nevi up to the present, such as atypical dots and globules, focal hypopigmentation, perifollicular hypopigmentation were observed in CMN, in our study. Congenital nevus and dysplastic nevi may share the same dermoscopic features, therefore it is important to know it is found at birth or not.

Intense Pulsed Light Alone and in Combination with Erbium Yttrium-Aluminum-Garnet Laser on Small-to-Medium Sized Congenital Melanocytic Nevi: Single Center Experience Based on Retrospective Chart Review

Background

Treatment of congenital melanocytic nevi (CMN) with intense pulsed light (IPL) has recently produced promising results.

Objective

To evaluate the clinical and histological outcomes of small-to-medium sized CMN treated with IPL alone and in combination with erbium: yttrium-aluminum-garnet (Er: YAG) laser.

Methods

We performed a retrospective chart review of 26 small-to-medium sized CMN treated as described above. The reduction in visible pigmentation, signs of recurrence and any adverse skin changes were evaluated by two independent clinicians.

Results

Seventeen patients completed treatment and were followed-up. Nine were not able to complete treatment due to work, change in residence, and treatment related stress. Ten patients received IPL alone (mean: 10.5 sessions) and 7 underwent treatment with IPL (mean: 7.7 sessions) and Er: YAG/IPL combination therapy (mean: 4.7 sessions). The initial treatment outcome was cleared in 5 patients and excellent in 12. Fourteen patients (82.4%) showed CMN recurrence one year after treatment completion. The histological results from a patient with an excellent clinical outcome showed remnant nevus cells nests in the deep dermis.

Conclusion

IPL treatment alone and in combination with Er: YAG laser are not definitive treatments for CMN and should not be considered as first-line treatment.

Brazilian guidelines for diagnosis, treatment and follow-up of primary cutaneous melanoma - Part II

The last Brazilian guidelines on melanoma were published in 2002. Development in diagnosis and treatment made updating necessary. The coordinators elaborated ten clinical questions, based on PICO system. A Medline search, according to specific MeSH terms for each of the 10 questions was performed and articles selected were classified from A to D according to level of scientific evidence. Based on the results, recommendations were defined and classified according to scientific strength. The present Guidelines were divided in two parts for editorial and publication reasons. In this second part, the following clinical questions were answered: 1) which patients with primary cutaneous melanoma benefit from sentinel lymph node biopsy? 2) Follow-up with body mapping is indicated for which patients? 3) Is preventive excision of acral nevi beneficious to patients? 4) Is preventive excision of giant congenital nevi beneficious to patients? 5) How should stages 0 and I primary cutaneous melanoma patients be followed?

Case report of nodular melanoma within congenital melanocytic nevus- primary closure challenge

•

Nodular melanoma that arose within congenital melanocytic nevus.

•

Total excision and defect reconstruction in a single stage.

•

Primary closure with triple Limberg flap.

Introduction

Congenital melanocytic nevi (CMN) are present in 1–2% of newborn infants. The size of CMN defines the risk of developing melanoma which is estimated from 5–10%, especially in lesions that are located across the spine.

Presentation of case

Herein we report a case where nodular melanoma was discovered on the periphery of medium sized CMN in a high risk patient. After complete excision, the defect was reconstructed with random pattern, triple rhomboid flap.

Discussion

Melanoma that arose within medium sized CMN would leave a complex posterior lower trunk defect. We used a triple Limberg flap which was proven to be straightforward and simple method when large defects are to be covered with vital tissue. We have also showed that this type of reconstruction is suitable for high risk patients that could not withstand any complex procedures.

Conclusion

In our case, the method we choose to reconstruct the defect proved to be simple, safe and easy, especially when surgery is performed in a high risk patient.

Oral Congenital Melanocytic Nevus: A Rare Case Report and Review of the Literature

Melanocytic nevi are congenital or acquired benign proliferations of cells of melanocytic origin. Oral congenital melanocytic nevi are rare, and only a few cases have been reported in the literature. The purpose of this study is to present the clinical, histological and immunohistochemical features of an oral congenital melanocytic nevus in a 16-year-old female with an 11-year follow-up and to review the pertinent literature. The reported case is the fifth well-documented case report of oral congenital melanocytic nevus in the English literature and the first with a long period of follow-up, thereby making it an important contribution to the knowledge regarding this uncommon oral mucosa lesion.

A case of neurocutaneous melanosis and neuroimaging findings

Neurocutaneous melanosis is a rare congenital disorder which presents with congenital cutaneous nevi and involvement of the central nervous system. We herein present a rare case of a 2-year-old girl who had central nervous system melanosis and giant congenital melanocytic nevi. Magnetic resonance imaging, especially precontrast T1 images play a crucial role in making the diagnosis combined with the skin findings of physical examination.

Nonpigmented metastatic melanoma in a two-year-old girl: a serious diagnostic dilemma

Although rare, malignant melanoma may occur in children. Childhood melanomas account for only 0.3-3% of all melanomas. In particular the presence of congenital melanocytic nevi is associated with an increased risk of development of melanoma. We herein report a case of malignant melanoma that developed on a giant congenital melanocytic nevus and made a metastasis to the subcutaneous tissue of neck in a two-year-old girl. The patient was hospitalized for differential diagnosis and treatment of cervical mass with a suspicion of hematological malignancy, because the malignant transformation of congenital nevus was not noticed before. In this case, we found out a nonpigmented malignant tumor of pleomorphic cells after the microscopic examination of subcutaneous lesion. Nonpigmented metastatic melanoma was diagnosed by several immunohistochemical and flow cytometric studies. She was offered palliative chemotherapy; however, her parents did not accept treatment. The patient died within 9 months of diagnosis. We emphasized here that the possibility of malignant melanoma in the differential diagnosis of childhood tumors should be kept in mind.

BRAF mutations are also associated with neurocutaneous melanocytosis and large/giant congenital melanocytic nevi

NRAS and BRAF mutations occur in congenital melanocytic nevi (CMN), but results are contradictory. Sixty-six prospectively collected CMN patients were analyzed for NRAS Q61 mutations using Sanger sequencing. Negative cases were evaluated for BRAF V600E mutation. NRAS Q61 mutations affected 51 patients (77.3%), and BRAF V600E was found in 5 (7.6%). NRAS Q61 mutation affected 29 (80.6%) of 36 giant, 16 (80.0%) of 20 large, and 5 (62.5%) of 8 medium-size CMN; BRAF mutation affected 1 (5%) of 20 large and 4 (11.4%) of 36 giant CMN. Compared to NRAS, BRAF-mutated nevi show scattered/extensive dermal and subcutaneous nodules (100% BRAF+ vs 34.8% NRAS+) (P=0.002). Neurocutaneous melanocytosis (NCM) affected 16 (24.2%) of 66 patients, with NRAS Q61 mutation in 12 (75.0%), and BRAF V600E in 2 (12.5%), P=0.009. Two patients were negative for both mutations (12.5%). In conclusion, although NRAS Q61 mutations predominate, BRAF V600E mutation also affects patients with large/giant CMN (L/GCMN), and with NCM, a novel finding. BRAF V600E is also associated with increased dermal/subcutaneous nodules. These findings open the possibility of BRAF-targeted therapy in some L/GCMN and NCM cases.

Neurocutaneous melanosis is associated with tethered spinal cord

PURPOSE

Neurocutaneous melanosis (NCM) is a rare congenital disorder occurring in children born with multiple or large congenital melanocytic nevi (CMN) in association with melanocytic deposits in the leptomeninges. Multiple associations between NCM and other syndromes or neurologic abnormalities have been reported. Of note, there exists a possible association between NCM and tethered cord (TC).

METHODS

We retrospectively reviewed charts and films of all patients with the diagnosis of NCM at the Children's Hospital of Pittsburgh (CHP) from August 2002 to present.

RESULTS

Five children met the criteria for NCM at our institution over a 12-year period. Apart from the melanocytic deposits, one or more additional spinal abnormalities were identified in all children. Three children had radiographic evidence of a low-lying conus medullaris, two of which also demonstrated lipomatous infiltration of the filum terminale, consistent with a tethered cord (TC).

CONCLUSIONS

Clinical features of NCM include dermatologic and neurologic manifestations. To date, this is the first series to note an association between NCM and TC. While nearly all recent series of NCM patients advocate early MRI of the neuroaxis, we recommend screening imaging of the spine on children with possible NCM regardless of the locations of CMN.

BRAF fusions define a distinct molecular subset of melanomas with potential sensitivity to MEK inhibition

PURPOSE

Recurrent "driver" mutations at specific loci in BRAF, NRAS, KIT, GNAQ, and GNA11 define clinically relevant molecular subsets of melanoma, but more than 30% are "pan-negative" for these recurrent mutations. We sought to identify additional potential drivers in "pan-negative" melanoma.

EXPERIMENTAL DESIGN

Using a targeted next-generation sequencing (NGS) assay (FoundationOne™) and targeted RNA sequencing, we identified a novel PAPSS1-BRAF fusion in a "pan-negative" melanoma. We then analyzed NGS data from 51 additional melanomas genotyped by FoundationOne™, as well as melanoma RNA, whole-genome and whole-exome sequencing data in The Cancer Genome Atlas (TCGA), to determine the potential frequency of BRAF fusions in melanoma. We characterized the signaling properties of confirmed molecular alterations by ectopic expression of engineered cDNAs in 293H cells.

RESULTS

Activation of the mitogen-activated protein kinase (MAPK) pathway in cells by ectopic expression of PAPSS1-BRAF was abrogated by mitogen-activated protein kinase kinase (MEK) inhibition but not by BRAF inhibition. NGS data analysis of 51 additional melanomas revealed a second BRAF fusion (TRIM24-BRAF) in a "pan-negative" sample; MAPK signaling induced by TRIM24-BRAF was also MEK inhibitor sensitive. Through mining TCGA skin cutaneous melanoma dataset, we further identified two potential BRAF fusions in another 49 "pan-negative" cases.

CONCLUSIONS

BRAF fusions define a new molecular subset of melanoma, potentially comprising 4% to 8% of "pan-negative" cases. Their presence may explain an unexpected clinical response to MEK inhibitor therapy or assist in selecting patients for MEK-directed therapy.

Skin of patients with large/giant congenital melanocytic nevi shows increased mast cells

Nevocytes (NC) and mastocytes (MC) have different progenitors but share stem cell factor as regulator/activator of NC and for differentiation/proliferation of MC. Both cell types express stem cell factor receptor CD117. We hypothesize that large/giant congenital melanocytic nevi (L/GCMN) may associate with MC hyperplasia. Forty-nine L/GCMN were examined, 12 samples from uninvolved skin of L/GCMN patients and 6 control skin samples studied with Giemsa and immunohistochemistry for CD117 and MC-tryptase. Picrosirius red (PR) was used to assess fibrosis. Digital images were used to count MC/mm(2) using ImageJ software. Western blot (WB) for MC-tryptase in 12 GCMN and 12 non-nevus samples was performed. Analysis of variance (Tukey) and Pearson statistical tests were applied. Increased MCs were observed in nevus tissue (75.1 ± 35.3 MCs/mm(2)) and in uninvolved skin (53.74 ± 27.7 MC/ mm(2)). P  =  0.109 from patients with L/GCMN, compared with controls from individuals without L/GCMN (28.74 ± 8.4 MC/mm(2)); P  =  0.001 supported by results of WB analysis for tryptase. A positive trend toward correlation of MC numbers with fibrosis, assessed by PR staining fell short of statistical significance (r  =  0.245; P  =  0.086); no difference in fibrosis was found between nevus and non-nevus skin from patients with L/GCMN (P  =  0.136). We found a higher density of MC, both in normal-appearing skin and nevus areas of L/GCMN patients, compared with control skin samples from individuals without nevi. Given the abnormal wound healing and allergic reactions described in L/GCMN patients, these findings suggest a potential role for MC in the biology of L/GCMN, making them a potential target for therapeutic intervention.

A newborn with neurocutaneous melanocytosis and Dandy-Walker malformation

BACKGROUND

Neurocutaneous melanocytosis is a rare congenital dysplasia of the neuroectodermal melanocyte precursor cells that leads to proliferation of melanin-producing cells in the skin and leptomeninges.

PATIENT

We describe a newborn with a giant congenital melanocytic nevus on his back, buttocks, and thighs. His brain magnetic resonance imaging study revealed bilateral T1 hyperintense lesions in the cerebellum and in the amygdala, hydrocephalus, and a Blake's pouch cyst, consistent with neurocutaneous melanocytosis and Dandy-Walker malformation.

CONCLUSION

Neurocutaneous melanocytosis has a wide clinical spectrum that includes hydrocephalus, epilepsy, cranial nerve palsy, increased intracranial pressure, and sensorimotor deficits.

Congenital and infantile benign skin lesions affecting the hand and upper extremity, part 2: nonvascular neoplasms

This article is part 2 of a 2-part series presented to aid the hand surgeon in becoming familiar with dermatological lesions that may be present on the upper extremity during infancy. The discussion focuses on nonvascular neoplasms grouped into the following categories: epithelial, melanocytic, histiocytic, dermal, fibroblastic, and adipocytic neoplasms. Diagnostic tips are offered, including clinical photographs, to help differentiate between these lesions. In addition, the recommended treatment for each is discussed.