Melanoma in infants, caused by a gene fusion involving the anaplastic lymphoma kinase (ALK)

We describe the first cases of pediatric melanoma with ALK fusion gene arising within giant congenital melanocytic nevi. Two newborn boys presented with large pigmented nodular plaques and numerous smaller satellite nevi. Additional expansile nodules developed within both nevi and invasive melanomas were diagnosed before 10 months of age in both boys. Oncogenic driver mutations in NRAS and BRAF were absent in both cases. Instead, oncogenic ZEB2::ALK fusion genes were identified in both the nevus and melanoma developing within the nevus. In both cases, tumors were noted by ultrasound in utero, demonstrated significant nodularity at birth, and progressed to melanoma in the first year of life suggesting that congenital nevi with ALK fusion genes may behave more aggressively than those with other mutations. As ALK kinase inhibitors are effective against a range of tumors with similar ALK fusion kinases, identifying ALK fusion genes in congenital melanocytic nevi may provide an opportunity for targeted therapy.

SCALP syndrome with a germline heterozygous DOCK6 mutation and somatic mosaic NRAS Q61R mutation

We present a case of SCALP syndrome, which was diagnosed in a male infant with the characteristic findings of sebaceous nevi, central nervous system malformations, aplasia cutis congenita, limbal dermoid, and giant congenital melanocytic nevi, or pigmented nevi. We identified a germline compound heterozygous DOCK6 mutation and a somatic mosaic NRAS Q61R mutation in the giant congenital melanocytic nevus. This report will increase clinician awareness of SCALP syndrome and augment the literature in characterizing this rare syndrome, including its genetic background.

Establishment and characterization of an immortalized human giant congenital melanocytic nevi cell line

Treatments for giant congenital melanocytic nevi (GCMN) are extremely limited. Thus, there is an urgent need for development of relevant targeted therapies. However, current lack of preclinical cell models restricts progress in GCMN research. In this study, we aimed to establish and characterize an immortalized GCMN cell line. GCMN cells were successfully immortalized by means of lentivirus-mediated simian virus 40 large T transfection. The immortalized GNC cell line (ImGNC) showed lower proliferation rate and higher melanin content than primary melanocytes. Expression levels of the differentiation gene MITF and stemness genes TWIST1, SNAI1, and FOXD3 were elevated in ImGNCs; however, the established ImGNC cell line was immortalized but not transformed. Sanger sequencing detected the heterozygous NRAS^Q61K mutation in ImGNCs, but not the BRAF^V600E mutation. Despite carrying the NRAS^Q61K allele, ImGNCs demonstrated suppressed MAPK activation and elevated PI3K/Akt activation, as compared with primary melanocytes. Drug sensitivity analysis showed that ImGNCs are more sensitive to PI3K/Akt and Bcl-2 inhibitors than to MEK or ERK inhibitors. Unlike the proliferation-inhibiting effect of PI3K/Akt inhibitors, the Bcl-2 inhibitor navitoclax promptly promoted apoptosis in ImGNCs. Considering the low proliferation characteristics of GCMN in vivo, Bcl-2 may be a potential therapeutic target that warrants further research.

Giant Congenital Melanocytic Nevi in a Pakistani Newborn

Congenital melanocytic nevi arise from overgrowth or disrupted migration of melanocyte precursor in the neural crest. They are also known as coat-sleeve, stocking, bathing trunk or garment nevi. The colour ranges from brown to black, with the lesions presenting as flat to raised nevi. Lesions presenting at birth with a diameter greater than 20cm are labelled giant congenital melanocytic nevi. Risk increases with an increase in the number of satellite lesions near the giant nevus. Management includes regular clinical follow-up monitoring of changes in the lesion and surgical procedures in cases with risk of melanoma and psychological support. The purpose of this case presentation is to describe a rare issue of giant congenital melanocytic nevi in a newborn, along with a literature review and discussion on possible management options.

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.

Two-stage surgical treatment of giant congenital melanocytic nevus around the auricle

BACKGROUND

This study presents the results of complete excision of giant congenital melanocytic nevi (GCMN) on the auricle, forehead, or periorbital area combined with tissue expansion, and skin graft transplantation performed in two stages based on 10 years of experience.

AIMS

To solve the giant congenital melanocytic nevi on the auricle, forehead, or periorbital area with two-stage operation.

PATIENTS/METHODS

A total of 21 patients with GCMN were included in this study. The operation combined tissue expander and skin graft transplantation.

RESULT

All GCMNs were successfully and completely excised. No patient in the study group had experienced skin contraction or auricular deformation at 3 years after treatment.

CONCLUSION

Two-stage operation is effective for removing GCMN on the auricle or face and can achieve good oncological and cosmetic results.

An alternative strategy treated giant congenital melanocytic nevi with epidermis and superficial dermis of the lesions

Giant congenital melanocytic nevi (GCMN) are defined as rare pigmented lesions that are believed to form between weeks 9 and 20 of gestation. It is difficult to reconstruct large defects after the removal of the lesions and it has posed a great challenge to the plastic surgeon and dermatologist.Given all those difficulty reconstructing the defects, we try to explore an alternative way to resurfacing the defect after removal of GCMN.Patients with GCMN received single-stage excision. Following the subcutaneous tissue and deep dermis were discarded, epidermis and superficial dermis were harvested as graft substitutes to reconstruct the defects in situ.All of the grafted tissue survived well and skin color in the surgical area gradually became lighter. During the periodicity of follow-up, neither hypertrophic scars nor recurrence were observed. Furthermore, histopathology examination demonstrated that there are no distinct melanocytes gathered in the postoperation lesions.For those GCMN which is difficult to reconstruct with traditional methods, resection of the lesion followed by reconstruction with epidermis skin and superficial dermis from the lesions in situ may be a feasible and alternative therapy method.

Tissue expansion in the treatment of giant congenital melanocytic nevi of the upper extremity

The aim of our study was to use tissue expansion for the treatment of giant congenital melanocytic nevi of the upper extremity and examine potential advantages over traditional techniques.There were 3 stages in the treatment of giant congenital melanocytic nevi of the upper extremities using tissue expansion: first, the expander was inserted into the subcutaneous pocket; second, the expander was removed, lesions were excised, and the wound of the upper extremity was placed into the pocket to delay healing; third, the residual lesion was excised and the pedicle was removed. The pedicle flap was then unfolded to resurface the wound.During the period between June 2007 and December 2015, there were 11 patients with giant congenital melanocytic nevi of the upper extremities who underwent reconstruction at our department with skin expansion. Few complications were noted in each stage of treatment. The functional and aesthetic results were observed and discussed in this study.Optimal aesthetic and functional results were obtained using tissue expansion to reconstruct the upper extremities due to the giant congenital melanocytic nevi.

An Exploratory Clinical Trial of a Novel Treatment for Giant Congenital Melanocytic Nevi Combining Inactivated Autologous Nevus Tissue by High Hydrostatic Pressure and a Cultured Epidermal Autograft: Study Protocol

Background

Giant congenital melanocytic nevi (GCMNs) are large brown to black skin lesions that appear at birth and are associated with a risk of malignant transformation. It is often difficult to reconstruct large full-thickness skin defects after the removal of GCMNs.

Objective

To overcome this difficulty we developed a novel treatment to inactivate nevus tissue and reconstruct the skin defect using the nevus tissue itself. For this research, we designed an exploratory clinical study to investigate the safety and efficacy of a novel treatment combining the engraftment of autologous nevus tissue inactivated by high hydrostatic pressurization with a cultured epidermal autograft (CEA).

Methods

Patients with congenital melanocytic nevi that were not expected to be closed by primary closure will be recruited for the present study. The target number of nevi is 10. The full-thickness nevus of the target is removed and pressurized at 200 MPa for 10 minutes. The pressurized and inactivated nevus is sutured to the original site. A small section of the patient’s normal skin is taken from around the nevus region and a CEA is prepared after a 3-week culturing process. The CEA is then grafted onto the engrafted inactivated nevus at four weeks after its retransplantation. The primary endpoint is the engraftment of the CEA at 8 weeks after its transplantation and is defined as being engrafted when the engraftment area of the inactivated nevus is 60% or more of the pretransplantation nevus area and when 80% or more of the transplanted inactivated nevus is epithelialized.

Results

The study protocol was approved by the Institutional Review Board of Kansai Medical University (No. 1520-2, January 5, 2016: version 1.3). The study opened for recruitment in February 2016.

Conclusions

This protocol is designed to show feasibility in delivering a novel treatment combining the engraftment of inactivated autologous nevus tissue and CEA. This is the first-in-man clinical trial of this treatment, and it should be a promising treatment of patients suffering from GCMN.

Trial Registration

University Hospital Medical Information Network: UMIN000020732; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000022198 (Archived by WebCite at http://www.webcitation.org/6jLZH2vDN)

Early diagnosis of asymptomatic neurocutaneous melanosis (60 month follow-up)

Neurocutaneous melanosis (NCM) is a rare, sporadic, congenital neuroectodermal dysplasia. Large congenital melanocytic nevi (CMN) can evolve in a certain percentage of patients to NCM. Meningeal deposits are benign, but can be prone to malignant transformation in some cases. We describe the case of an infant with asymptomatic NCM, and typical magnetic resonance imaging (MRI) findings. The diagnosis was established shortly after delivery, and the patient was followed for 60 months. At that time, the girl did not have any neurologic symptoms; she reached normal developmental milestones and did not show mental retardation and did not develop malignant melanoma; further follow-up will be needed, although there are no reliable guidelines as to the time range of follow up of asymptomatic NCM in the literature. We report the typical MRI signal abnormalities of the brain, and present a review of the literature regarding this rare and mysterious congenital disorder.

Nevospheres from neurocutaneous melanocytosis cells show reduced viability when treated with specific inhibitors of NRAS signaling pathway

BACKGROUND

Neurocutaneous melanocytosis (NCM) is characterized by clonal nevomelanocytic proliferations in the CNS and skin. Given the scarcity of effective therapeutic targets, testing new drugs requires a reliable and reproducible in vitro cellular model of the disease.

METHODS

We generated nevomelanocytic spheroids in vitro from lesions of the spinal cord, brain, and skin from 4 NCM patients. Nevomelanocytic cells were grown as monolayers or spheroids and their growth characteristics were evaluated. Cultured cell identity was confirmed by demonstration of the same NRAS mutation found in the original lesions and by immunophenotyping. Nevomelanocytic spheroids were treated with inhibitors of specific mediators of the NRAS signaling pathway (vemurafenib, MEK162, GDC0941, and GSK2126458). Drug sensitivity and cell viability were assessed.

RESULTS

Cultured cells were growth-factor dependent, grew as spheroids on Geltrex matrix, and maintained their clonogenicity in vitro over passages. Skin-derived cells formed more colonies than CNS-derived cells. Inhibitors of specific mediators of the NRAS signaling pathway reduced viability of NRAS mutated cells. The highest effect was obtained with GSK2126458, showing a viability reduction below 50%.

CONCLUSIONS

NRAS mutated cells derived from clinical NCM samples are capable of continuous growth as spheroid colonies in vitro and retain their genetic identity. Drugs targeting the NRAS signaling pathway reduce in vitro viability of NCM cells. NCM lesional spheroids represent a new and reliable experimental model of NCM for use in drug testing and mechanistic studies.