Neurocutaneous melanosis: Follow-up and literature review

The Usefulness of High-Frequency Ultrasound in the Management of Patients with Giant Congenital Melanocytic Nevi: A Cohort Prospective Study

OBJECTIVES

Congenital melanocytic nevi (CMN) exhibit various clinical presentations. Dermoscopy and confocal microscopy only assess the superficial dermis. Magnetic resonance imaging cannot evaluate skin layers comprehensively. High-frequency Doppler ultrasound (HFUS) can define the extent of melanocytic lesions and suggest patterns of potential complications. The objective of the study is to evaluate HFUS characteristics of patients with CMN and, secondarily, to study the utility of HFUS in evaluating proliferative nodules and enlarged lymph nodes.

METHODS

A prospective study of patients with multiple and non-small CMN between January 2016 and June 2021 was conducted. Clinical imaging and HFUS were routinely used to follow up on distinctive areas. A retrospective analysis of HFUS images and correlation with presentation was performed.

RESULTS

Seventy-one patients with CMN, 149 HFUS scans. Median age: 14 years (IQR: 8 months-79 years), 59% female. Large/giant nevi n = 44 (61.9%). CMN affected the epidermis/dermis in 51 (71.8%), hypodermis in 17 (24%), and muscle in 3 (4.2%). Thirteen patients (18.3%) had nodular lesions; 1 showed atypical vessels on HFUS, which was confirmed histologically as an atypical proliferative nodule.

LIMITATIONS

Heterogeneity of patients and retrospective analysis.

CONCLUSIONS

HFUS allows the characterization of non-small CMN by assessing depth and diagnosing complications such as melanomas and enlarged lymph nodes.

Spinal melanoma with optic neuropathy -rare manifestation of Neurocutaneous melanosis and PET-MRI findings

Neurocutaneous melanocytosis (NCM) is a rare, sporadic neuroectodermal dysplasia characterized by the presence of large or multiple congenital cutaneous nevi and melanocytic deposits in the central nervous system. Hitherto, unreported we describe a case of NCM with optic neuropathy and spinal cord melanoma from India. A 20 year-old-lady had headache and vomiting for 3 months followed by consecutive profound painless visual impairment. Visual acuity was counting of fingers at 1 m distance in both eyes with normal fundus. There were no symptoms of spinal cord involvement. Clinical examination showed multiple small to large melanocytic nevi over the face and body. Muscle power was normal. Tendon reflexes were exaggerated. Visual evoked potential showed bilateral prolonged P100 latency (Right eye - 144 msec; Left eye - 151 msec). Brain MRI revealed leptomeningeal enhancement of brainstem, cerebellum, oculomotor and facial-abducent nerve complex without optic nerve involvement. MRI spine showed extensive dorsal thoracic cord epidural lesion extending along the entire thoracic cord segment with dorsal cord compression. Positron Emission Tomography (PET) imaging showed Fludeoxyglucose F18 (FDG) avidity along D1-D12 levels of spinal cord. Biopsy from the cord lesion was suggestive of meningeal melanoma. Here we document a rare case of late onset NCM with intracranial meningeal infiltration and asymptomatic large epidural lesion of spinal cord, expanding its phenotypic spectrum. Optic neuropathy in NCM has not been reported earlier. Periodic screening of brain and spine is recommended for early prognostication and lesion identification in NCM.

Neurocutaneous melanosis with an intracranial cystic-solid meningeal melanoma in an adult: A case report and review of literature

BACKGROUND

Neurocutaneous melanosis (NCM) is a rare congenital, nonhereditary neurocutaneous syndrome that mainly occurs in children; adult NCM is very rare. Due to its rarity, the clinical features and treatment strategies for NCM remain unclear. The purpose of this study was to explore the clinical features, diagnosis, treatment and prognosis of NCM in adults. Most intracranial meningeal melanomas are solid masses, and cystic-solid malignant melanomas are very rare. Due to the lack of data, the cause of cystic changes and the effect on prognosis are unknown.

CASE SUMMARY

A 41-year-old woman was admitted to the hospital with intermittent headache for 1 mo. Magnetic resonance imaging (MRI) showed a 4.7 cm × 3.6 cm cystic-solid mass in the left temporal lobe with peritumoral edema. The entire mass was removed, and postoperative pathology indicated malignant melanoma.

CONCLUSION

MRI is the first-choice imaging approach for diagnosing central nervous system diseases in NCM patients, although cerebrospinal fluid may also be used. At present, there is no optimal treatment plan; gross total resection combined with BRAF inhibitors and MEK inhibitors might be the most beneficial treatment.

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.

Congenital Melanocytic Nevus: Considerations for Neonatal Clinicians and a Parent Perspective

Congenital melanocytic nevus (CMN) or nevi, also known as dark moles, are present at birth. While small CMN are quite common, large and giant nevi are rare and can be associated with significant psychological distress and the potential for further clinical sequelae. Neonatal clinicians can offer anticipatory guidance to families through distribution of resources and navigation to additional consultants.

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.

Pediatric primary diffuse leptomeningeal melanomatosis: Case report and review of the literature

RATIONALE

Primary melanocytic tumors of central nerve system (CNS) are rare, primary diffuse leptomeningeal melanomatosis (PDLM), a subtype of malignant melanomas of CNS, is extremely rare,especially in pediatrics. As the clinical manifestation of PDLM is not characteristic, It is often misdiagnosed as tubercular meningitis and hemorrhage.

PATIENT CONCERNS

A 13-year-old boy was admitted to our department with symptoms of recurrent headache and vomiting twice. As the brain imaging revealed a lesion located in the left temporal lobe mimicked hemorrhage, so there was a misdiagnosis of hemorrhage in first hospitalization. He was admitted again for the recurrence of the headache and vomiting. Detailed physical examination showed multiple melanin changes in the skin of the whole body which were ignored in last hospitalization. Brain imaging showed the significantly enlarged lesion in the left temporal lobe and several smaller lesions in the left parietal lobe and cerebellum which indicated metastasis.

DIAGNOSIS

According to the history,physical examination and the radiological finding, the patient was diagnosed with malignant melanoma of central never system possibly.

INTERVENTIONS

The patient underwent left temporal and parietal lesions total resection with a craniotomy.

OUTCOMES

The diagnosis of PDLM was established according to pathological characteristics and the negative finding of positron emission tomography (PET)-computed tomography (CT) outside CNS. The patient got no further treatment for economic reasons and experienced the progression and died 5 months after operation.

LESSONS

PDLM is extremely rare in CNS, as the clinical manifestation, radiological changes are not special, early diagnosis is difficult. The confirmed diagnosis is established by leptomeningeal biospy or surgical tissue. PET-CT can help differential diagnosis with metastastic leptomeningeal melanomas. The prognosis is dismal due to the inefficiency of chemotherapy or radiotherapy.

Mosaic Neurocutaneous Disorders and Their Causes

Neurocutaneous disorders are a heterogeneous group of conditions (mainly) affecting the skin [with pigmentary/vascular abnormalities and/or cutaneous tumours] and the central and peripheral nervous system [with congenital abnormalities and/or tumours]. In a number of such disorders, the skin abnormalities can assume a mosaic patterning (usually arranged in archetypical patterns). Alternating segments of affected and unaffected skin or segmentally arranged patterns of abnormal skin often mirror similar phenomena occurring in extra-cutaneous organs/tissues [eg, eye, bone, heart/vessels, lung, kidney and gut]. In some neurocutaneous syndromes the abnormal mosaic patterning involve mainly the skin and the nervous system configuring a (true) mosaic neurocutaneous disorder; or an ordinary trait of a neurocutaneous disorder is sometimes superimposed by a pronounced linear or otherwise segmental involvement; or, lastly, a neurocutaneous disorder can occur solely in a mosaic pattern. Recently, the molecular genetic and cellular bases of an increasing number of neurocutaneous disorders have been unravelled, shedding light on the interplays between common intra- and extra-neuronal signalling pathways encompassing receptor-protein and protein-to-protein cascades (eg, RAS, MAPK, mTOR, PI3K/AKT and GNAQ pathways), which are often responsible of the mosaic distribution of cutaneous and extra-cutaneous features. In this article we will focus on the well known, and less defined mosaic neurocutaneous phenotypes and their related molecular/genetic bases, including the mosaic neurofibromatoses and their related forms (ie, spinal neurofibromatosis and schwannomatosis); Legius syndrome; segmental arrangements in tuberous sclerosis; Sturge-Weber and Klippel-Trenaunay syndromes; microcephaly/megalencephaly-capillary malformation; blue rubber bleb nevus syndrome; Wyburn-Mason syndrome; mixed vascular nevus syndrome; PHACE syndrome; Incontinentia pigmenti; pigmentary mosaicism of the Ito type; neurocutaneous melanosis; cutis tricolor; speckled lentiginous syndrome; epidermal nevus syndromes; Becker's nevus syndrome; phacomatosis pigmentovascularis and pigmentokeratotica; Proteus syndrome; and encephalocraniocutaneous lipomatosis.

Giant congenital melanocytic nevi: selected aspects of diagnostics and treatment

Background

Treatment of giant melanocytic nevi (GMN) remains a multidisciplinary challenge. We present analysis of diagnostics, treatment, and follow-up in children with GMN to establish obligatory procedures in these patients.

Material/Methods

In 24 children with GMN, we analyzed: localization, main nevus diameter, satellite nevi, brain MRI, catecholamines concentrations in 24-h urine collection, surgery stages number, and histological examinations. The t test was used to compare catecholamines concentrations in patient subgroups.

Results

Nine children had “bathing trunk” nevus, 7 had main nevus on the back, 6 on head/neck, and 2 on neck/shoulder and neck/thorax. Brain MRI revealed neurocutaneous melanosis (NCM) in 7/24 children (29.2%), symptomatic in 1. Among urine catecholamines levels from 20 patients (33 samples), dopamine concentration was elevated in 28/33, noradrenaline in 15, adrenaline in 11, and vanillylmandelic acid in 4. In 6 NCM children, all catecholamines concentrations were higher than in patients without NCM (statistically insignificant). In all patients, histological examination of excised nevi revealed compound nevus, with neurofibromatic component in 15 and melanoma in 2. They remain without recurrence/metastases at 8- and 3-year-follow-up. There were 4/7 NCM patients with more than 1 follow-up MRI; in 1 a new melanin deposit was found and in 3 there was no progression.

Conclusions

Early excision with histological examination speeds the diagnosis of melanoma. Brain MRI is necessary to confirm/rule-out NCM. High urine dopamine concentration in GMN children, especially with NCM, is an unpublished finding that can indicate patients with more serious neurological disease. Treatment of GMN children should be tailored individually for each case with respect to all medical/psychological aspects.

Oncogenic codon 13 NRAS mutation in a primary mesenchymal brain neoplasm and nevus of a child with neurocutaneous melanosis

A 28-month female with a clinical diagnosis of neurocutaneous melanosis and numerous intracranial abnormalities (including a right choroid plexus tumor and left hemimegalencephaly) presented with a rapidly expanding tumor in the left occipital cerebrum. Microscopic examination of the resected specimen revealed a myxoid mesenchymal neoplasm consisting of fusiform cells that were immunoreactive for vimentin, CD34, and P53 but no melanocyte markers. Focused amplicon deep sequencing on DNA extracted from the brain tumor and a cutaneous nevus revealed a heterozygous (c.37G > C; p.G13R) substitution in the NRAS gene. DNA sequencing of “normal” skin and buccal swab showed the identical NRAS change albeit at lower allelic frequency. Her parents did not harbor the NRAS mutation. The skin lesion, but not the brain tumor, had a BRAF mutation (c.1397G > T; p.G466V). A germline single nucleotide polymorphism in MET was found in the child and her father (c.3209C > T; p.T1010I). The findings suggest NRAS mosaicism that occurred sometime after conception and imply an oncogenic role of the activating NRAS mutation in both the brain and skin lesions in this child.

Neurocutaneous melanocytosis

Neurocutaneous melanosis or neurocutaneous melanocytosis is a rare sporadic congenital disorder characterized by the presence of giant and/or multiple satellite congenital melanocytic nevi in the skin and benign melanocytic pigmentation of the leptomeninges. These two defining features were recognized more than a century ago. A third characteristic feature is proliferative nodules arising from giant nevi. The etiology is unknown, but neurocutaneous melanosis is considered a developmental disorder of melanocyte precursors from neural crest. The distinctive unique distribution of the congenital giant nevi that gives a "garment" appearance is also an expression of the neural crest. The neurological manifestations often appear in infancy.The special association of neurocutaneous melanosis with Dandy-Walker malformation complex may be explained by a common pathogenesis. Mortality in infancy and childhood is high.

[Current place of curettage in the management of giant congenital nevi: report of 29 patients]

SUBJECT

The management of giant nevi remains discussed to date. Curettage, early superficial technique, allows a lightening of the lesions. We wanted to define the current interest in its use, from results obtained after 20 years of experience.

PATIENTS AND METHODS

Twenty-nine patients were treated by curettage between 1991 and 2011. Surgery consisting of excision of the superficial dermis was performed between the 1st and 7th week of life in an average of 1.8 procedures. The cosmetic result was judged subjectively.

RESULTS

Healing was achieved in 7 days. We noted a few local complications but no general complications. The aesthetic results, with initial variable lightening, induced an overall parental satisfaction in 100 % of cases. A secondary heterogeneous and varying pigmentation was observed in all cases.

CONCLUSION

To date, we believe that curettage is indicated for the treatment of giant nevi in some localization difficult to treat by conventional techniques (eyebrow, those associated with many satellite nevi) or those with a psychological impact too important to support a therapeutic delay.

[Asymptomatic neonatal neurocutaneous melanosis]

Giant congenital nevi in 1% of cases are associated with anomalies of the central nervous system, which are characteristic of neurocutaneous melanosis. When neurocutaneous melanosis becomes symptomatic, it is associated with a poor prognosis. With recommended neonatal screening, asymptomatic neonatal cases are being discovered more frequently. On the basis of this observation, we consider various aspects of this association.