Association of melanoma and neurocutaneous melanocytosis with large congenital melanocytic naevi--results from the NYU-LCMN registry

Refinements in the Preexpanded Distant Flap for Giant Melanocytic Nevi of the Upper Extremity in Pediatric Patients

BACKGROUND

Surgical treatment of large and giant congenital melanocytic nevi (GCMN) of the upper extremity is challenging because of limited options for reconstruction. A preexpanded distant flap is considered an important option in upper extremity reconstruction, where the soft tissue available for use is limited. The authors aimed to refine the preexpanded distant flap after excision of the GCMN in the upper extremity.

METHODS

Large (>10 cm) and giant (>20 cm) congenital melanocytic nevi of the upper extremities treated with tissue expansion and distant flaps over 10 years were retrospectively reviewed, and the authors describe in detail the surgical strategies for reconstruction of the upper extremity with a distant flap.

RESULTS

From March of 2010 to February of 2020, 13 patients (mean age, 2.87 years) treated with 17 preextended distant flaps were included. The mean flap dimension was 154.87 cm 2 , ranging from 15 × 5 to 26.5 × 11 cm. All procedures were successfully completed except for one, in which partial flap necrosis occurred. Preconditioning was performed before flap transfer in 5 patients with larger rotation arcs and flap dimensions. The mean duration of postoperative follow-up was 51.85 months. A new reconstructive protocol was proposed that combined the 3 elements, including a distant flap, tissue expander, and preconditioning.

CONCLUSIONS

In the treatment of GCMN in the upper extremities, careful planning and multiple stages are required. For pediatric patients, the preextended distant flap with preconditioning is useful and effective for reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Prevalence, incidence density and standardized morbidity rate of melanoma among patients with congenital melanocytic naevi: a systematic review

BACKGROUND

Congenital melanocytic naevi (CMN) are the result of aberrations in the mitogen-activated protein kinase signal transduction pathway. The risk of melanoma is the most important concern among patients with CMN because of its poor prognosis. However, as a result of the great variability between studies, the reported risk of melanoma varies considerably, making it difficult to provide reliable information.

OBJECTIVES

To evaluate the prevalence, incidence density and standardized morbidity ratio (SMR) of melanoma among patients with CMN.

METHODS

We conducted a systematic literature search of studies providing data on the risk of melanoma in patients with CMN following our registered and published protocol (PROSPERO: CRD42022383009).

RESULTS

Overall, 27 studies with a total of 11 480 patients with CMN and 82 patients developing melanoma were included for analysis. The prevalence of melanoma was 1.84% [95% confidence interval (CI) 1.13-2.99] in patients with CMN and 2.73% (95% CI 1.67-4.43) in the subgroup of patients with large CMN (LCMN). The incidence of melanoma was 237.56 (95% CI 97.79-575.96) per 100 000 person-years in patients with CMN and 585.73 (95% CI 315.39-1085.29) per 100 000 person-years in the LCMN subgroup. The SMR of melanoma was 122.27 (95% CI 11.84-1262.88) among all patients with CMN and 285.97 (95% CI 50.65-1614.59) in the subgroup of patients with LCMN.

CONCLUSIONS

Our research suggests that the risk of melanoma in the CMN population seems to have been overestimated in previous studies, but it is still significantly higher than that in the general population. In addition to the risk of melanoma, aesthetic improvement and mental health should also be taken into account when making management decisions.

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.

A BEST classification system of large to giant congenital melanocytic nevi based on expert consensus and distribution characteristics

BACKGROUND

Large to giant congenital melanocytic nevi (LGCMN) significantly decrease patients' quality of life, but the inaccuracy of current classification system makes their clinical management challenging.

OBJECTIVES

To improve and extend the existing LGCMN 6B/7B classification systems by developing a novel LGCMN classification system based on a new phenotypic approach to clinical tool development.

METHODS

Three hundred and sixty-one LGCMN cases were categorized into four subtypes based on anatomic site: bonce (25.48%), extremity (17.73%), shawl (19.67%) and trunks (37.12%) LGCMN. A 'BEST' classification system of LGCMN was established and validated by a support vector machine classifier combined with the 7B system.

RESULTS

The most common LGCMN distributions were on bonce and trunks (bathing trunk), whereas breast/belly and body LGCMN were exceptionally rare. Sexual dimorphism characterized distribution, with females showing a wider range of lesions in the genital area. Nearly half of the patients with bathing trunk LGCMN exhibited a butterfly-like distribution. Approximately half of the LGCMN with chest involvement did not have nipple-areola complex involvement. Abdomen, back and buttock involvement was associated with the presence of satellite nevi (r = 0.558), and back and buttock involvement was associated with the presence of nodules (r = 0.364).

CONCLUSIONS

The effective quantification of a standardized anatomical site provides data support for the accuracy of the 6B/7B classification systems. The simplified BEST classification system can help establish a LGCMN clinical database for exploration of LGCMN aetiology, disease management and prognosis prediction.

Incidence of neurocutaneous melanosis in Japanese pediatric patients with congenital melanocytic nevi

Neurocutaneous melanosis (NCM) is a rare, non-hereditary neurocutaneous disorder characterized by excessive melanocytic proliferation in the skin and central nervous system. As no major studies have covered the incidence of NCM among Japanese patients with congenital melanocytic nevi (CMN), we prospectively investigated the incidence of NCM among Japanese patients who underwent initial treatment for CMN. The relationship of CMN and NCM was also investigated. Japanese pediatric patients with CMN under 1 year of age were included between January 2020 and November 2022, and all patients underwent brain MRI to check for NCM in this study. NCM lesions were most frequently seen in the amygdala, followed by the cerebellum, brainstem, and cerebral hemispheres. NCM was diagnosed on brain MRI in 31.6% of the 38 patients with CMN and in 25.0% of patients with no prior examination or treatment. Distribution and size of CMN, number of satellite nevi, rugosity and nodules were strongly associated with the existence of NCM, and these findings may guide a future registry study with a large cohort of CMN patients.

Risk of melanoma in congenital melanocytic nevi of all sizes: A systematic review

Congenital melanocytic nevi (CMN) are commonly encountered benign skin lesions in newborns. Larger CMN is associated with a higher lifetime risk of developing melanoma. However, the level of risk is unclear when CMN are small or medium-sized. Our objective was to assess melanoma risk in patients with CMN of all size categories. A literature review with meta-analysis was performed. Prevalence and incidence densities of melanoma at onset were calculated in the entire study population and according to CMN size, type of treatment and location of the CMN. A total of 91 melanomas were reported in 7915 patients (1.15%, 95% CI, 0.93-1.41). The overall incidence density was 0.057% person-years (95% CI_, 0.044-0.071). The risk ratio of melanoma incidence densities was 21.9 (95% CI, 8.55-56.3) in large to giant CMN compared with small to medium CMN at 15 years of age. The incidence density was higher in CMN located on the trunk and as well as in those which were untreated or partially treated versus complete excision. Our review suggests patients with CMN of medium, large and giant size are at risk of melanoma, whereas the risk remains unknown for small CMN.

Combinatorial effects of azacitidine and trametinib on NRAS-mutated melanoma

Congenital melanocytic nevus (CMN) syndrome represents a mosaic RASopathy, typically caused by postzygotic NRAS codon 61 mutations, which originate in ectodermal precursor cells and result in melanocyte deposits in the skin and central nervous system (CNS). Affected patients are prone to develop uniformly fatal melanomas in the skin and CNS. Here, we report the case of a 2.7-year-old male with CMN syndrome, diffuse leptomeningeal melanosis and CNS melanoma, who underwent experimental therapy with the DNA methyltransferase inhibitor azacitidine in combination with the mitogen-activated protein kinase (MEK) inhibitor trametinib with exceptional clinical and radiological response. Response to combination therapy appeared to be more durable than the treatment response observed in several other severely affected patients treated with trametinib for late-stage disease. Correspondingly, concomitant exposure to trametinib and azacitidine prevented development of trametinib resistance in NRAS-mutated human melanoma cells in vitro. Also, azacitidine was shown to inhibit growth and mitogen-activated protein kinase 1/2 (ERK1/2) phosphorylation of melanoma cells and act synergistically with trametinib to inhibit the growth of trametinib-resistant melanoma cells. These observations suggest that azacitidine enhances trametinib monotherapy and may represent a promising candidate drug for combination therapies to enhance the efficacy of MEK inhibitors in RAS-driven diseases.

Neurological signs, symptoms and MRI abnormalities in patients with congenital melanocytic naevi and evaluation of routine MRI-screening: systematic review and meta-analysis

Background

A congenital melanocytic naevus (CMN) is a rare skin condition that can be associated with abnormalities of the central nervous system (CNS). These anomalies can sometimes cause severe complications, and rarely death. Adequate information about aetiology and management is therefore crucial. To identify how to monitor patients with CMN, we aimed to estimate the prevalence of neurological involvement in patients with CMN and to summarize what specific neurological signs and symptoms and MRI abnormalities are reported in the medical literature. In addition, we summarized and evaluated the recommendations regarding MRI-screening reported in the medical literature.

Methods

This review was registered in PROSPERO and reported according to the MOOSE checklist. A search was conducted in EMBASE (Ovid), PubMed, and the Cochrane Library. We included studies with 10 or more patients with CMN, reporting on neurological signs and symptoms or CNS MRI. Study selection, data extraction and methodological quality assessment were performed by two independent reviewers. A meta-analysis was used to assess the prevalence of neurological signs and symptoms.

Results

Out of 1287 studies, fourteen studies were eligible for inclusion of which eight were included in the meta-analysis. Neurological signs and symptoms prevalence was 7.04% (CI 95% 4.47–10.93%) in the meta-analysis group and 6.26% (95% CI 3.85–10%) in a subgroup of patients with a CMN > 6 cm, evaluated in seven studies. Neurodevelopmental delay and seizures were the most frequently reported signs and symptoms. CNS melanocytosis and hydrocephalus were the most frequently reported MRI abnormalities. It was not possible to estimate the increased risk of neurological involvement in patients with CMN due to low quality of evidence and clinical heterogeneity.

Conclusion

Standardization in CMN studies and a multi-centre prospective study are needed to evaluate neurological involvement. Based on current literature, it is not possible to make strong recommendations on routine MRI-screening. For now, every clinical centre should decide on its own policy and weigh the advantages and disadvantages of routine MRI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02234-8.

Genodermatoses associated with melanocytic nevi

Though melanocytic nevi are ubiquitous in the general population, they can also be key cutaneous manifestations of genetic syndromes. We describe genodermatoses associated with melanocytic nevi and discuss their clinical characteristics, cutaneous manifestations, underlying genetics, and, if applicable, guidelines for when genetic testing should be performed. We categorized these genodermatoses based on their association with congenital nevi, acquired nevi, or nevi whose first appearance is unknown. In many cases, the distinctive morphology or distribution of melanocytic nevi can be an important clue that an underlying genetic syndrome is present, allowing both the patient as well as family members to be screened for the more serious complications of their genetic disorder and receive education on potential preventative measures. As we continue to advance our understanding of how various genotypes give rise to the wide spectrum of phenotypes observed in these genodermatoses, we shall be able to better stratify risk and tailor our screening methods to clinically manage the heterogeneous manifestations of genodermatoses among these patients.

Risk of Malignant Transformation Arising From Giant Congenital Melanocytic Nevi: A 20-year Single-center Study

BACKGROUND

Although giant congenital melanocytic nevus (GCMN) is regarded as premalignant, the incidence and risk factors of malignant transformation are controversial.

OBJECTIVE

This study aimed to share the authors' surgical experience with GCMNs and provide data on their demographics, malignant transformation, and prognosis.

METHODS

This single-center, consecutive study included 152 patients with GCMN who visited this center from March 2000 to February 2020. Their medical documentation was reviewed retrospectively, and the nevi were classified according to the size as follows: Group 1, 10 to 19.9 cm (n = 45); Group 2, 20 to 39.9 cm (n = 62); and Group 3, ≥40 cm (n = 45).

RESULTS

Seven malignancies were found (4.6%; 4 melanomas, 2 rhabdomyosarcomas [RMS], and 1 malignant peripheral nerve sheath tumor [MPNST]). The risk increased according to the nevus size (2.2% in Group 1, 3.2% in Group 2, and 8.9% in Group 3) but the difference was not statistically significant (p = .3305).

CONCLUSION

Malignant transformation from GCMN cannot be ignored. It can include transformation into melanoma, RMS, and MPNST. Early surgical resection and regular follow-up should be performed in patients with nevi ≥10 cm.

Surgical outcomes and psychosocial impact of giant congenital melanocytic nevus surgery: A single-center case series of 136 patients

PURPOSE

The aim of this study was to evaluate the outcomes, complications and psychosocial impact of surgical treatment of giant congenital melanocytic nevus (GCMN).

METHODS

Patients with surgically treated GCMN who attended our clinic between May 2014 and May 2018 were included. Patient demographics and data on the characteristics of the nevus, surgical treatment, and the psychosocial impact (including C-DLQI/DLQI questionnaires) were collected.

RESULTS

One hundred thirty-six patients were included (median age 9 years). Mean age at first surgery was 34 (+/- 61.45) months; 5.53 (+/- 3.69) surgical interventions were necessary to completely excise the nevus. The expanded skin flap was the preferred surgical technique in most locations. Complications were common but not severe. Of the patients studied, 70.4% reported that the surgery had a minor impact on their quality of life (QoL). Patients and caregivers stated that surgical treatment should begin as soon as possible, even in cases where early treatment did not have an impact on their QoL nor on their satisfaction with the surgery (p < 0.05). The lower the patient age at first surgery, the higher the surgeon's satisfaction (p < 0.01).

CONCLUSIONS

Surgical treatment is a safe option for management of GCMN, and has a low impact on QoL. Patients, caregivers, and surgeons agree that the treatment should begin as soon as possible. This is the largest single-center study evaluating surgical treatment in GCMN patients and its psychosocial impact, and the first to take into account the patient, caregivers and dermatologists opinion of surgical results.

Neurocutaneous melanocytosis-associated malignant melanoma presenting with peritoneal seeding

Neurocutaneous melanocytosis (NCM) is characterized by melanocyte deposition in the leptomeninges and brain parenchyma, primarily occurring in children with large or giant congenital melanocytic nevi (LCMN) or multiple congenital melanocytic nevi. Patients with NCM may develop hydrocephalus and increased intracranial pressure, which can be managed with ventriculoperitoneal (VP) shunting. We present the case of a 16-month-old girl who developed peritoneal carcinomatosis and malignant ascites following VP shunting for hydrocephalus secondary to NCM to increase awareness of this rare, but serious, complication of cerebrospinal fluid diversion.

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.

Cerebellar amelanotic melanoma can mimic cerebellar abscess in a pediatric case of neurocutaneous melanosis

Neurocutaneous melanosis (NCM) is a rare phakomatosis that may be associated with intracerebral masses. The differential diagnosis of intracerebral masses in NCM is often challenging and should include pigmented and nonpigmented lesions.

Distribution Patterns (7B Rule) and Characteristics of Large Congenital Melanocytic Nevi: A Retrospective Cohort Study in China

Large congenital melanocytic nevus has a high risk of malignancy. However, few studies have summarized its characteristics, treatments, outcomes and malignancy incidence in Chinese patients. This paper reviews a retrospective cohort study evaluating 1,171 patients from Shanghai Ninth People's Hospital between 1 January 1989 and 31 August 2019 using electronic medical records and phone calls to collect clinical and pathological data in which 133 patients were diagnosed with a large congenital melanocytic nevus. Three patients relapsed, and none developed melanoma among the qualified patients. Besides, a new “7B” rule for distribution patterns of large congenital melanocytic nevi was proposed, including bonce, bolero, back, bathing trunk, breast/belly, body extremity, and body. The most common distribution pattern of large congenital melanocytic nevi was bonce, and all blue nevi distributed as bonce. Statistical analysis showed a significant difference (P = 0.0249) in the “7B” patterns between the melanocytic nevus and the neuronevus. In conclusion, the malignancy rate of large congenital melanocytic nevi is much lower in China than in other regions and people of other races. The pathology of large congenital melanocytic nevus may decide its “7B” distribution pattern.

Congenital melanocytic naevi: An up-to-date overview

Congenital melanocytic naevi are hamartomas of the neuroectoderm caused by genetic mosaicism. Congenital melanocytic naevi are seen in 1-6% of all live births and commonly classified based on the projected size in adults. Congenital melanocytic naevi appear in different colours, shapes, and sizes, and occasionally present with complications. In this review, we sought to evaluate congenital melanocytic naevi, their clinical, dermatoscopic, and reflectance confocal microscopic features, behavioural pattern over time, new trends in classification, underlying genetic factors and their influence on clinical manifestations and management, associated risks, complications, magnetic resonance imaging findings and their management in the light of recent literature.

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).

Cosmetically Challenging Congenital Melanocytic Nevi

BACKGROUND

Congenital melanocytic nevi (CMN) have a 1% to 5% lifetime risk for malignant transformation, with 50% of transformations occurring before the age of 5 years.The aim of this study is to assess the risk of melanoma development in pediatric patients with facial CMN involving the eyebrows, eyelid margins, and nasal alae where a margin of CMN was not excised to preserve these structures.

METHODS

A retrospective chart review of all pediatric patients with CMN from 1986 to 2014 was performed to review demographic information, diagnosis, and number of surgeries. Patients' clinical photographs were evaluated for residual nevi after completion of the treatment.

RESULTS

More than 950 medical charts of patients with CMN of the face area were reviewed. We identified 32 patients (13; 41% male) that met the study criteria with pathology-confirmed diagnosis of facial CMN with an average age of 4.4 years (3.3 months-15.8 years) at the time of initial surgery. The CMNs were classified into small (1; 3%), medium (14; 44%), large (14; 44%), and giant (3; 9%) based on their projected adult sizes. No patients developed melanoma within the small residual lesions left over the eyebrows and eyelids and inside nostrils at an average follow-up time of 5.6 (1.0-14.4) years and average age of 9.6 (1.8-19.2) years at the time of last follow-up.

CONCLUSIONS

Although a lifelong risk of malignant transformation of the residual CMN cannot be concluded, our results found no transformation in follow-up visits at an average age beyond the highest risk of melanoma development in childhood. We feel that leaving residual lesions on the face in areas of important anatomic structures for better cosmetic outcome is an acceptable risk.

[Early-onset melanoma (congenital, neonatal, infantile): A systematic review of literature cases]

INTRODUCTION

Neonatal and infantile malignant melanoma is rare. It may be difficult to diagnose and often carries a poor prognosis.

MATERIAL AND METHODS

We decided to review the data on congenital, neonatal and infantile malignant melanomas in order to understand their presentation (clinical, histological, molecular), diagnosis, management and outcomes. We performed a literature search of all cases of early-onset melanoma published in PubMed from its inception to March 2019 using the following keywords: "malignant melanoma" OR "melanoma" OR "pigmented nevus" OR "malignant pigmented" AND "infantile" OR "congenital" OR "children" OR "childhood" OR "infancy" OR "neonatal". Congenital melanoma associated with maternal-foetal transmission was not included in the study.

RESULTS

Sixty-five articles were selected and 85 cases were included in the study. Most patients were male (sex ratio: 1.6). The average age at diagnosis was 5.5 months (minimum-maximum: 0-24 months). The main site reported for congenital melanoma was the head-and-neck area and for neonatal and infantile melanoma the trunk. Half of all patients had a metastatic disease at the time of diagnosis. In metastatic cases, the prognosis was poor with the exception of patients undergoing complete excision of the tumour and metastases. The main treatment for cutaneous melanomas and operable metastasis was surgery, and secondarily, chemotherapy/immunotherapy.

CONCLUSION

Neonatal and infantile malignant melanoma are rarely reported and not well-documented. It is necessary to collect additional cases to improve our knowledge of this rare disease.

Epilepsy in isolated parenchymal neurocutaneous melanosis: A systematic review

PURPOSE

Neurocutaneous melanosis (NCM) is a rare congenital syndrome characterized by giant melanocytic cutaneous nevi and melanosis within the central nervous system (CNS), often sparing leptomeninges and concentrated in the brain parenchyma. Epilepsy and neurodevelopmental abnormalities are the only complications reported in children with isolated parenchymal melanosis. A minority of patients experience drug-resistant epilepsy, and up to now, no predictors of epilepsy prognosis have been identified.

METHODS

In this systematic review, according to preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, we aggregated clinical cases of patients with isolated parenchymal melanosis affected by epilepsy, in order to recognize predictors of clinical outcome and to clarify indications of available therapeutic approaches.

RESULTS

Sixteen articles (19 patients) were included in the final analysis from initial database research; 4 articles (4 patients) were selected from reference lists and 1 from conference abstracts (1 patient). In our series, distribution of parenchymal melanosis was the best predictor of epilepsy outcome: frequencies of seizure-free patients were different between cases of isolated/bilateral amygdale melanosis and those of multiple localizations (p = 0.037). Failure of antiepileptic drugs (AEDs) and/or surgical epilepsy therapy were associated with poor cognitive outcome (p = 0.03).

CONCLUSION

Antiepileptic drugs were effective in the majority of patients with epilepsy with parenchymal melanosis. In case of multifocal distribution, more than one-third of patients presented a drug-resistant epilepsy. Epilepsy surgery is the best choice in patients with isolated amygdala localization. We propose the recognition of a multifactorial nature of cognitive impairment in neuromelanosis, emphasizing the role of drug-resistant epilepsy.

Malignant melanoma in a child with giant congenital melanocytic nevus and satellite flekers: A rare entity

Malignant melanomas in the pediatric age are remarkably rare representing 0.9% of various pediatric malignancies. Congenital nevi occur in 1 in 100 newborns, whereas giant congenital melanocytic nevus (GCMN) measuring more than 20 cm is seen in 1 in 20 000 cases. Very few cases of malignant melanoma arising from GCMN have been described in English literature. The risk of developing malignant melanoma from GCMN is believed to be directly proportional to the size of the nevus and varies from 2.6% to 20% depending on the size of nevus. We present a case of malignant melanoma in a 12-year-old female child who had a congenital giant nevus and multiple satellite flekers all over the body.

Mosaicism in genodermatoses

Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.

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.

Management of Congenital Melanocytic Nevus on Face Using Multiple Re-expansion Method: Aesthetic and Psychosocial Results

BACKGROUND

Congenital giant melanocytic nevus on the face is a challenging condition, especially in the pediatric population. It can produce significant cosmetic deformity with negative psychosocial effects in pediatric patients even after treatment. The objective of this study was to report aesthetic and psychosocial results in the management of congenital melanocytic nevus on the face using multiple reexpansion.

METHODS

Data of 6 patients with congenital melanocytic nevus on the face who underwent excision and multiple reexpansion at our center from September 2004 to August 2017, were retrospectively reviewed. To evaluate aesthetic outcomes, preoperative and final photographs of each patient were reviewed by 3 other plastic surgeons and 4 laypersons. For comparison, 6 other patients who were treated with conventional surgery during the same period were reviewed. After final reconstruction surgery, the authors surveyed patients' satisfaction via telephone.

RESULTS

Six patients were followed up for an average of 87.66 months (range, 55-123 months). The mean number of tissue expander insertions was 3.33 and the mean number of total expanders inserted was 4.83. Complication associated with expander exposure occurred in 1 patient during the fifth expansion. The average score of aesthetic outcome in the multiple reexpansion group was superior to that of the conventional group (2.60 versus 2.10, P = 0.03). During the telephone survey, patients did not rate their appearance as positive, although they were comparatively satisfied with the surgical procedure.

CONCLUSION

Considering the low rate of malignancy involving congenital melanocytic nevus in childhood, multiple reexpansion is an attractive option to obtain better results compared with other reconstructive methods.

Does the gene matter? Genotype-phenotype and genotype-outcome associations in congenital melanocytic naevi

Background

Genotype–phenotype studies can identify subgroups of patients with specific clinical features or differing outcomes, which can help shape management.

Objectives

To characterize the frequency of different causative genotypes in congenital melanocytic naevi (CMN), and to investigate genotype–phenotype and genotype–outcome associations.

Methods

We conducted a large cohort study in which we undertook MC1R genotyping from blood, and high‐sensitivity genotyping of NRAS and BRAF hotspots in 156 naevus biopsies from 134 patients with CMN [male 40%; multiple CMN 76%; projected adult size (PAS) > 20 cm, 59%].

Results

Mosaic NRAS mutations were detected in 68%, mutually exclusive with BRAF mutations in 7%, with double wild‐type in 25%. Two separate naevi were sequenced in five of seven patients with BRAF mutations, confirming clonality. Five of seven patients with BRAF mutations had a dramatic multinodular phenotype, with characteristic histology distinct from classical proliferative nodules. NRAS mutation was the commonest in all sizes of CMN, but was particularly common in naevi with PAS > 60 cm, implying more tolerance to that mutation early in embryogenesis. Facial features were less common in double wild‐type patients. Importantly, the incidence of congenital neurological disease, and apparently of melanoma, was not altered by genotype; no cases of melanoma were seen in BRAF‐mutant multiple CMN, however, this genotype is rare.

Conclusions

CMN of all sizes are most commonly caused by mutations in NRAS. BRAF is confirmed as a much rarer cause of multiple CMN, and appears to be commonly associated with a multinodular phenotype. Genotype in this cohort was not associated with differences in incidence of neurological disease in childhood. However, genotyping should be undertaken in suspected melanoma, for guidance of treatment.

What's already known about this topic?

Multiple congenital melanocytic naevi (CMN) have been shown to be caused by NRAS mosaic mutations in 70–80% of cases, by BRAF mosaicism in one case report and by inference in some previous cases.

There has been debate about genotypic association with different sizes of CMN, and no data on genotype–outcome.

What does this study add?

NRAS mosaicism was found in 68%, BRAF in 7% and double wild‐type in 25% of cases of CMN.

NRAS was the commonest mutation in all sizes of CMN, but was nearly universal in projected adult size > 60 cm.

BRAF is often associated with a distinct multinodular clinical/histological phenotype.

Adverse outcomes did not differ between genotypes on current numbers.

https://doi.org/10.1111/bjd.18747 available online

Mosaic abnormalities of the skin: review and guidelines from the European Reference Network for rare skin diseases

BACKGROUND

Cutaneous mosaicism is an area of dermatology in which there has been an explosion of knowledge within the current decade. This has led to fundamental changes in the understanding of the conditions in this field, and to an ongoing paradigm shift in the approach to management of mosaic skin disorders.

OBJECTIVES

To lay out the general principles of mosaicism as they are currently understood, summarize the known cutaneous mosaic abnormalities of the skin with associated phenotypic and genotypic information, review the latest trials on targeted therapies and propose guidelines for the general approach to a patient with suspected mosaicism.

METHODS

This was a consensus expert review as part of the European Reference Network project (ERN-Skin).

CONCLUSIONS

This study provides clinicians with a practical approach to the patient with suspected mosaicism, redefines mosaicism for the modern genetic era, and proposes a new classification system based on genetic mechanism. What's already known about this topic? Cutaneous mosaicism is a complex field of dermatology that encompasses most birthmarks, and many rare syndromes. Some cutaneous patterns are known to be seen in mosaicism. Very few treatment options are available for most mosaic abnormalities of the skin. Recent high-sensitivity genetic techniques have led to an explosion of knowledge about genotype and phenotype in the literature. What does this study add? Expert consensus from the European Reference Network project. Review of knowledge of confirmed mosaic abnormalities of the skin, including cutaneous phenotype, extracutaneous associated features and genotype. Proposed new classification of mosaic abnormalities of the skin by genetic mechanism and therefore inheritance potential. Practical tips on correct sample collection and genetic investigation. Review of trials of targeted therapies. Guidelines for a practical clinical approach to the patient with suspected mosaicism.

Malignant transformation of neurocutaneous melanosis (NCM) following immunosuppression

Neurocutaneous melanosis (NCM) is the condition of abnormal melanocyte deposition in the leptomeninges and brain parenchyma. Associated with congenital melanocytic nevi, NCM can result in neurologic deficits, hydrocephalus, and rarely, malignant transformation of cells. We present the case of a 16-year-old boy with NCM who developed malignant leptomeningeal melanoma following immunosuppression with a TNFα inhibitor. To our knowledge, this is the first reported case of a patient with known NCM undergoing malignant transformation after anti-TNF therapy for inflammatory bowel disease.

Melanoma arising in a Giant congenital melanocytic nevus: two case reports

Background

A giant congenital melanocytic nevus (GCMN) is found in 0.1% of live-born infants. If present, the lesion has a chance of about 6% to develop into malignant melanoma. Both children and adults can be affected by malignant melanoma arising in a giant congenital nevus. Up to 95% of GCMNs harbor NRAS mutations, and mutations in the BRAF, MC1R, TP53, and GNAQ genes have also been described. The individualization of therapy is required, but diagnostic and prognostic criteria remain controversial.

Case presentations

We report two cases: 1) melanoma arising in a giant congenital nevus during the first month of life complicated with neurocutaneous melanosis (NCM), and 2) melanoma arising in a giant congenital nevus during the first 6 months of life. Pathology, immunohistochemistry, and genetic analyses of tumor tissue were performed. The first case revealed only a non-pathogenic P72R polymorphism of the TP53 gene in the homozygote condition. For the second case, a Q61K mutation was detected in the NRAS gene.

Conclusion

Malignant melanoma associated with GCMN is rare and therefore poorly understood. Outcomes have been linked to the stage at diagnosis, but no additional pathological prognostic factors have been identified. The most frequent genetic event in giant CMNs is NRAS mutations, which was discovered in one of our cases. To accumulate evidence to improve disease prognosis and outcomes, children with congenital melanocytic nevus should be included in a systemic follow-up study from birth.

New insights into neurocutaneous melanosis

BACKGROUND

Neurocutaneous melanosis is a rare disorder in which children with large cutaneous melanotic nevi have associated melanosis in the brain. Although many affected children have structurally normal brains, some have associated developmental disorders or brain anomalies.

OBJECTIVES

To determine the range of extent of brain melanosis as assessed by magnetic resonance imaging (MRI) and to investigate the frequency and types of associated brain anomalies.

MATERIALS AND METHODS

We retrospectively reviewed brain and spine MRIs of 80 patients with congenital melanocytic nevi (range: 1 day to 22 years of age) affiliated with Nevus Outreach Inc. from 1998 to 2017. Central nervous system (CNS) melanosis was diagnosed when a mass with abnormal parenchymal T1 hyperintensity was seen. The locations of abnormal signal, associated malformations, the presence of contrast enhancement and, in patients with more than one MRI, changes over time were recorded. Associations among findings were analyzed using chi-square test or Fisher exact test.

RESULTS

Brain abnormalities were identified in 33 patients. The most common finding was melanosis in the amygdala, which was found in 31 patients (an isolated finding in 14 patients). Nineteen patients had melanosis in the brainstem, cerebellum, cerebral cortex or thalamus. Cerebral and/or spinal leptomeningeal enhancement was uncommon (five patients). Hindbrain melanosis was associated with cerebellar and pontine hypoplasia (P=0.012). Brain melanosis was most easily seen on T1 images prior to myelination; reduced/loss of visibility was noted as the CNS matured.

CONCLUSION

Brain melanosis is a common manifestation in children with large cutaneous melanotic nevi, most commonly found in the anterior temporal lobes (amygdala), brainstem, cerebellum and cerebral cortex. Hindbrain melanosis is associated with hypoplasia of the affected structures. Early imaging is optimal to provide the greatest sensitivity for diagnosis and to guide proper management.

Neurocutaneous Melanosis with Leptomeningeal Melanoma Involving Supratentorium and Infratentorium

Neurocutaneous melanoma is a rare congenital syndrome associated with congenital melanocytic nevi with meningeal melanosis or melanoma. The disease is aggressive and has a high propensity for leptomeningeal metastases. We present the case history of a man with neurocutaneous melanoma managed with radical excision followed by hypofractionated adjuvant radiotherapy. One year, eight months later, he had a recurrence of the condition with leptomeningeal spread and was managed with re-excision of the recurrent lesion. Although our patient was disease-free for 20 months after the initial surgery, he survived only approximately five months after the second surgery, which reflects the associated poor prognosis of the disease.

A Practical Approach to the Diagnosis of Melanocytic Lesions

CONTEXT.—

Melanocytic lesions are common in routine surgical pathology. Although the majority of these lesions can be confidently diagnosed using well-established morphologic criteria, there is a significant subset of lesions that can be diagnostically difficult. These can be a source of anxiety for patients, clinicians, and pathologists, and the potential consequences of a missed diagnosis of melanoma are serious.

OBJECTIVE.—

To provide a practical approach to the diagnosis of melanocytic lesions, including classic problem areas as well as suggestions for common challenges and appropriate incorporation of ancillary molecular techniques.

DATA SOURCES.—

Literature search using PubMed and Google Scholar, incorporating numerous search terms relevant to the particular section, combined with contemporaneous texts and lessons from personal experience.

CONCLUSIONS.—

Although a subset of melanocytic lesions can be diagnostically challenging, the combination of a methodical approach to histologic assessment, knowledge of potential diagnostic pitfalls, opinions from trusted colleagues, and judicious use of ancillary techniques can help the pathologist navigate this difficult area.

Congenital melanocytic nevi in young children: Histopathologic features and clinical outcomes

BACKGROUND

Although only large congenital melanocytic nevi (CMN) are associated with a significantly high risk for malignant transformation, CMN of all sizes are prone to changes in clinical appearance in early childhood and thus are often biopsied or excised. While CMNs typically exhibit benign behavior, atypical histopathologic findings might be common and may prompt additional unnecessary procedures.

OBJECTIVE

To assess the prevalence and associated clinical outcomes of atypical histopathologic features in CMN in children.

METHODS

A single center retrospective study was conducted with patients 0-35 months of age with CMN diagnosed by histopathology between 1993-2013.

RESULTS

One hundred seventy-nine patients with a total of 197 CMNs were identified. Cytologic atypia, architectural disorder, or pagetoid spread were present in 73% of CMN. With a mean follow up of 7.3 years, no cases of melanoma or CMN-related deaths were identified.

LIMITATIONS

Our findings were based on a largely Caucasian population and might not apply to darker skin types. Our findings might not apply to older children or adults with CMN.

CONCLUSION

Atypical histopathologic features of cytologic atypia, architectural disorder, and pagetoid spread are common in benign CMN of young children.

A prospective study of patients with large congenital melanocytic nevi and the risk of melanoma

BACKGROUND:

Large congenital melanocytic nevus (LCMN) is considered a risk factor for melanoma, although the magnitude of this risk is controversial.

OBJECTIVE:

To evaluate the risk of melanoma development in patients with LCMN seen at a dermatology referral center in Brazil during a twelve-year period. To the best of our knowledge, there are no published similar studies on large congenital melanocytic nevus in South America.

METHODS:

Our prospective cohort included only patients with congenital nevi ≥20cm. The cumulative risk of developing melanoma and the standardized morbidity ratio were calculated for patients followed up prospectively for at least 1 month.

RESULTS:

Sixty-three patients were enrolled in this study. One patient who developed melanoma prior to enrollment was excluded, and five were eliminated because of insufficient follow-up time. Mean follow-up for the remaining 57 patients was 5.5 years (median 5.2 years). Median age of entry into the study was 2.6 years. Most patients (75.4%) underwent only clinical observation. Melanomas occurred in 2 (3.5%) patients. Five-year cumulative risk for melanoma was 4.8% (95% CI: 1.9-11.5%). Standardized morbidity ratio was 1584 (95% CI: 266-5232, p<0.001).

STUDY LIMITATIONS:

The small sample size reduces the accuracy of risk estimates.

CONCLUSIONS:

This study analyzed prospectively for the first time data from South America demonstrating that patients with LCMN have a higher risk of developing melanoma than the general population (p<0.001).

Congenital melanocytic nevi: update in genetics and management

PURPOSE OF REVIEW

The article intends to review recent updates in the management of congenital melanocytic nevi (CMN) and the evolving genomic landscape that has begun to shed light on the nature of nevogenesis, malignant potential, and possible therapeutic targets for those with melanoma and neurologic involvement.

RECENT FINDINGS

CMN are the result of postzygotic somatic mutations involving key proteins in the mitogen-activated protein kinase pathway, primarily NRAS and BRAF. Complications include a spectrum of neurologic findings and development of melanoma. Patients with extracutaneous involvement may be better termed as having 'CMN syndrome'. MRI findings in high risk patients with multiple CMN may best predict clinical outcome.

SUMMARY

The management of patients with CMN is complex. Neurologic involvement and melanoma remain the two most devastating complications. New, genetically targeted therapies for patients with complications may be of value, and research for potential therapies is ongoing.

Melanocytic Nevi in Children: A Review

Common moles on the skin, known scientifically as melanocytic nevi, are seen frequently in the pediatric population. They are broadly grouped into two groups: congenital (generally present at birth or in infancy) or acquired. Congenital melanocytic nevi (CMN) are classified based on size and morphologic features. Neurocutaneous melanosis and melanoma represent two important complications, with overall risk affected by nevus size, location, appearance, and number of satellite lesions. Regular lifelong skin surveillance is required for high-risk CMN. Acquired melanocytic nevi (AMN) tend to appear in childhood and increase in number through adolescence. Risk factors for melanoma in children with moles include having more than 50 AMN, clinically atypical AMN, family history of melanoma, excessive ultraviolet light exposure, lightly pigmented skin, and immunosuppression. Children with risk factors should be monitored regularly. The periodic health examination presents an opportunity to perform total body skin examination to screen for concerning lesions and to provide anticipatory guidance about sun protection. [Pediatr Ann. 2016;45(8):e293-e298.].

Metastatic melanoma in association with a giant congenital melanocytic nevus in an adult: controversial CGH findings

Giant congenital melanocytic nevi (GCMNs) represent a distress to patients for 2 reasons: one is disfigurement, and the other is the increased risk of developing secondary melanocytic tumors, such as benign proliferative nodules (BPNs) and malignant melanoma (MM). BPN present as a rapid growth nodule arising within a congenital melanocytic nevus (CMN) that often ulcerates, occurs in children younger than 2 years of age. BPNs arising within a CMN are exceedingly rare after childhood, and very few cases have been described in adults. Despite the worrisome clinical and histologic findings of BPN, most laboratory investigations seem to support their benignity. The distinction between MM and BPN is extremely important, but the histopathology of BPN of GCMN can be a challenge to differentiate from MM. In the recent years, molecular tests that investigate DNA copy number alterations such as fluorescence in situ hybridization and comparative genomic hybridization have shown promise to help guide the diagnosis of ambiguous melanocytic proliferations arising within CMNs. We report the case of a 22-year-old woman with a nodule arising in a GCMN and with an axillary mass suggesting a nodal metastasis of melanoma, and discuss the unusual clinical, histopathologic, and molecular findings that make this case particularly interesting.

Characteristics, treatment, and survival of invasive malignant melanoma (MM) in giant pigmented nevi (GPN) in adults: 976 cases from the National Cancer Data Base (NCDB)

BACKGROUND

Malignant melanoma (MM) arising in a giant pigmented nevus (GPN) is a rare disease in adults with no large series published to our knowledge.

OBJECTIVE

We sought to describe the characteristics, treatment, and survival of MM in GPN for adults.

METHODS

Adults with invasive MM in GPN (n = 976) reported to the National Cancer Data Base from 1998 to 2012 were evaluated for patient and tumor characteristics, treatment, and survival. For comparison, data from adults with invasive superficial spreading melanoma (SSM) (n = 111,870) and nodular melanoma (n = 35,962) were used.

RESULTS

Compared with patients with SSM, patients with MM in GPN had a thicker Breslow depth, more positive lymph nodes, and distant metastasis more frequently. Multivariate analysis identified age older than 65 years, Breslow thickness greater than 2 mm, presence of ulceration, presence of distant metastasis, and positive margins as independent predictors of survival in patients with MM in GPN. At all stages, having MM in GPN has similar overall survival compared with SSM.

LIMITATIONS

The study is retrospective and registry-based.

CONCLUSIONS

Invasive MM in GPN occurs in adults, with overall survival similar to SSM. Clinicians should be aware of the continued risk of MM in adults with GPN with low threshold for biopsy.

Classification of neurological abnormalities in children with congenital melanocytic naevus syndrome identifies magnetic resonance imaging as the best predictor of clinical outcome

Background

The spectrum of central nervous system (CNS) abnormalities described in association with congenital melanocytic naevi (CMN) includes congenital, acquired, melanotic and nonmelanotic pathology. Historically, symptomatic CNS abnormalities were considered to carry a poor prognosis, although studies from large centres have suggested a much wider variation in outcome.

Objectives

To establish whether routine MRI of the CNS is a clinically relevant investigation in children with multiple CMN (more than one at birth), and to subclassify radiological abnormalities.

Methods

Of 376 patients seen between 1991 and 2013, 289 fulfilled our criterion for a single screening CNS MRI, which since 2008 has been more than one CMN at birth, independent of size and site of the largest naevus. Cutaneous phenotyping and radiological variables were combined in a multiple regression model of long‐term outcome measures (abnormal neurodevelopment, seizures, requirement for neurosurgery).

Results

Twenty‐one per cent of children with multiple CMN had an abnormal MRI. Abnormal MRI was the most significant predictor of all outcome measures. Abnormalities were subclassified into group 1 ‘intraparenchymal melanosis alone’ (n = 28) and group 2 ‘all other pathology’ (n = 18). Group 1 was not associated with malignancy or death during the study period, even when symptomatic with seizures or developmental delay, whereas group 2 showed a much more complex picture, requiring individual assessment.

Conclusions

For screening for congenital neurological lesions a single MRI in multiple CMN is a clinically relevant strategy. Any child with a stepwise change in neurological/developmental symptoms or signs should have an MRI with contrast of the brain and spine to look for new CNS melanoma.

What's already known about this topic?

Multiple congenital melanocytic naevi (CMN; more than one lesion at birth) can be associated with abnormalities of the central nervous system (CNS). The spectrum of these abnormalities includes congenital and acquired pathologies, melanotic and nonmelanotic lesions, rendering the term ‘CMN syndrome’ more appropriate than ‘neurocutaneous melanosis’.

Symptomatic CNS abnormalities were previously thought to carry a universally poor prognosis, although cohort data in the last decade have argued against this.

What does this study add?

A single CNS magnetic resonance imaging scan in multiple CMN, independent of projected adult size or site of the largest naevus, and ideally in the first 6 months of life, is currently an appropriate screening strategy.

An abnormal result is a better statistical predictor of clinical outcome than cutaneous phenotype.

Clinical management is altered as a result of the radiological result.

Giant congenital melanocytic nevi and neurocutaneous melanosis

Introduction. The major medical concern with giant congenital melanocytic nevi CMN is high risk of developing cutaneous melanoma, leptomeningeal melanoma, and neurocutaneous melanocytosis. Case Report. A 30-year-old woman with a giant congenital melanocytic nevus covering nearly the entire right thoracodorsal region and multiple disseminated melanocytic nevi presented with neurological symptoms. Cerebral magnetic resonance imaging revealed a large expansive lesion in the left frontal region. Postsurgically pathological diagnosis revealed characteristics of melanoma. Immunohistochemical examination showed S100(+), HMB45(+), MelanA(+), and MiTF(+). She received radiotherapy with temozolomide followed by two more chemotherapy cycles with temozolomide. She followed a rapidly progressive course, reflecting widespread leptomeningeal infiltration, and she died of multiorgan failure seven months after diagnosis of cerebral melanoma. Discussion. This patient was diagnosed as having a neurocutaneous melanosis with malignant widespread leptomeningeal infiltration. Diffuse spinal involvement is unusual and is described in only another patient.

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.

Update on melanocytic nevi in children

A new or changing melanocytic nevus in a child or adolescent often leads to concern in parents and physicians. To avoid undue alarm and unnecessary procedures, dermatologists should be aware of the natural history and clinical spectrum of nevi in pediatric patients, as well as findings that are potentially worrisome in this age group. This review provides an update on melanocytic nevi in children, focusing on their dynamic evolution over time, molecular insights into nevogenesis, and phenotypic markers for increased risk of melanoma in adolescence and adulthood. Special considerations for Spitz nevi and nevi located in particular sites (eg, scalp, acral, genital) are highlighted. Current understanding of the risks associated with congenital melanocytic nevi of different sizes and strategies for the management of children with numerous acquired nevi, Spitz nevi, and congenital nevi are also discussed.

Giant congenital melanocytic nevus

Giant congenital melanocytic nevus is usually defined as a melanocytic lesion present at birth that will reach a diameter ≥ 20 cm in adulthood. Its incidence is estimated in <1:20,000 newborns. Despite its rarity, this lesion is important because it may associate with severe complications such as malignant melanoma, affect the central nervous system (neurocutaneous melanosis), and have major psychosocial impact on the patient and his family due to its unsightly appearance. Giant congenital melanocytic nevus generally presents as a brown lesion, with flat or mammilated surface, well-demarcated borders and hypertrichosis. Congenital melanocytic nevus is primarily a clinical diagnosis. However, congenital nevi are histologically distinguished from acquired nevi mainly by their larger size, the spread of the nevus cells to the deep layers of the skin and by their more varied architecture and morphology. Although giant congenital melanocytic nevus is recognized as a risk factor for the development of melanoma, the precise magnitude of this risk is still controversial. The estimated lifetime risk of developing melanoma varies from 5 to 10%. On account of these uncertainties and the size of the lesions, the management of giant congenital melanocytic nevus needs individualization. Treatment may include surgical and non-surgical procedures, psychological intervention and/or clinical follow-up, with special attention to changes in color, texture or on the surface of the lesion. The only absolute indication for surgery in giant congenital melanocytic nevus is the development of a malignant neoplasm on the lesion.