Inflammatory linear verrucous epidermal nevus in groin and labia with claudication: Successfully treated with photodynamic therapy.

SIGNIFICANCE: Inflammatory linear verrucous epidermal nevus (ILVEN) is an uncommon type of epidermal nevus and is refractory to therapy. We report the effectiveness of photodynamic therapy (PDT) for treating ILVEN with claudication in a young girl. ADDITIONAL CONTRIBUTIONS: We thank the patient for granting permission to publish this information. APPROACH: Aminolaevulinic Acid Hydrochloride (ALA) photodynamic therapy (PDT) was applied six times in 1-month interval. RESULTS: Most lesions and pruritus have subsided markedly, with mild scarring and a marked reduction in claudication. CONCLUSIONS: ALA PDT might be an effective and promising treatment for ILVEN in the future.

Expansion of the complex genotypic and phenotypic spectrum of FGFR2-associated neurocutaneous syndromes.

The fibroblast growth factor receptors comprise a family of related but individually distinct tyrosine kinase receptors. Within this family, FGFR2 is a key regulator in many biological processes, e.g., cell proliferation, tumorigenesis, metastasis, and angiogenesis. Heterozygous activating non-mosaic germline variants in FGFR2 have been linked to numerous autosomal dominantly inherited disorders including several craniosynostoses and skeletal dysplasia syndromes. We report on a girl with cutaneous nevi, ocular malformations, macrocephaly, mild developmental delay, and the initial clinical diagnosis of Schimmelpenning-Feuerstein-Mims syndrome, a very rare mosaic neurocutaneous disorder caused by postzygotic missense variants in HRAS, KRAS, and NRAS. Exome sequencing of blood and affected skin tissue identified the mosaic variant c.1647=/T > G p.(Asn549=/Lys) in FGFR2, upstream of the RAS signaling pathway. The variant is located in the tyrosine kinase domain of FGFR2 in a region that regulates the activity of the receptor and structural mapping and functional characterization revealed that it results in constitutive receptor activation. Overall, our findings indicate FGFR2-associated neurocutaneous syndrome as the accurate clinical-molecular diagnosis for the reported individual, and thereby expand the complex genotypic and phenotypic spectrum of FGFR-associated disorders. We conclude that molecular analysis of FGFR2 should be considered in the genetic workup of individuals with the clinical suspicion of a mosaic neurocutaneous condition, as the knowledge of the molecular cause might have relevant implications for genetic counseling, prognosis, tumor surveillance and potential treatment options.

Schimmelpenning-Feuerstein-Mims syndrome with benign enlargement of subarachnoid space in infancy.

Schimmelpenning-Feuerstein-Mims syndrome is a rare disorder generally characterised by a craniofacial nevus with multisystemic presentations. Our patient, an infant, was brought to the emergency department in a postictal state following a first seizure episode. A physical examination showed a solitary dark brown, well-demarcated verrucous plaque extending from the patient's left temporal region to the left mandible without crossing the midline. Epibulbar choristomas were present on the ipsilateral side of the craniofacial lesion. Neuroimaging showed benign enlargement of the subarachnoid space. Due to the known risk of seizures associated with this condition, the patient was started on levetiracetam and showed adequate compliance. We present this as the first reported case of Schimmelpenning-Feuerstein-Mims syndrome with benign enlargement of the subarachnoid space in an infant presenting with seizures to emphasise the value of collaboration among multidisciplinary professionals to improve the quality of care for such patients.

Schimmelpenning-Feuerstein-Mims syndrome induced by HRAS Gly12Ser somatic mosaic mutation: Case report and literature review.

Schimmelpenning-Feuerstein-Mims syndrome (SFMS), an epidermal nevus disease, features skin lesions including craniofacial nevus sebaceous and extracutaneous anomalies (e.g. brain, eye, and bone). Recent genetic studies implicate HRAS, KRAS, and NRAS genes in somatic mutations. Our case, a 48-year-old man, presented with nevus sebaceous on the scalp; pigmented skin lesions on the right side of his neck, back, and chest along the Blaschko lines; a history of epilepsy; and mild intellectual disability. Accordingly, SFMS was suspected. DNA analysis of nevus sebaceous skin and peripheral blood leukocytes showed a pathogenic HRAS variant NM_005343.4:c.34G > A p.(Gly12Ser) in biopsy specimens from different skin layers but not blood, indicating somatic mosaic mutation. Until now, the HRAS p.(Gly12Ser) mutation has been reported in somatic RASopathies but not SFMS. The authors report this mutation in a case of SFMS, review another 15 cases of SFMS, and discuss HRAS c.34G > A p.(Gly12Ser) somatic mutations. RAS mutations of somatic RASopathies share activating hotspot mutations found in cancers, and produce different phenotypes depending on the developmental stage at which the somatic mutations occur.

A case of successful treatment of concurrent verrucous epidermal naevi and psoriasis with apremilast.

In a rare case of concurrent verrucous epidermal naevi (VEN) with psoriasis, previous treatments with oral methotrexate and acitretin showed minimal improvement. However, treatment with oral apremilast resulted in complete resolution of psoriasis and significant improvement in VEN lesions after 1 month. This is the first documented case of successful VEN treatment with apremilast, highlighting its potential efficacy in treating verrucous epidermal naevus. Further studies are needed to validate its effectiveness.

Reversibility and developmental neuropathology of linear nevus sebaceous syndrome caused by dysregulation of the RAS pathway.

Linear nevus sebaceous syndrome (LNSS) is a neurocutaneous disorder caused by somatic gain-of-function mutations in KRAS or HRAS. LNSS brains have neurodevelopmental defects, including cerebral defects and epilepsy; however, its pathological mechanism and potentials for treatment are largely unclear. We show that introduction of KRASG12V in the developing mouse cortex results in subcortical nodular heterotopia and enhanced excitability, recapitulating major pathological manifestations of LNSS. Moreover, we show that decreased firing frequency of inhibitory neurons without KRASG12V expression leads to disrupted excitation and inhibition balance. Transcriptional profiling after destabilization domain-mediated clearance of KRASG12V in human neural progenitors and differentiating neurons identifies reversible functional networks underlying LNSS. Neurons expressing KRASG12V show molecular changes associated with delayed neuronal maturation, most of which are restored by KRASG12V clearance. These findings provide insights into the molecular networks underlying the reversibility of some of the neuropathologies observed in LNSS caused by dysregulation of the RAS pathway.

Verrucous epidermal nevus as a manifestation of a type 2 mosaic PTEN mutation in Cowden syndrome.

Linear Cowden nevus, also known as linear PTEN nevus, is a type of epidermal nevus, first described in 2007, which is seen in patients with PTEN hamartoma tumor syndrome. It is considered to be a type 2 form of segmental mosaicism, and we suggest that it has certain clinical features that distinguish it from epidermal nevi seen in similar conditions, such as Proteus syndrome. We present a case of linear Cowden nevus in a 4-year-old boy and review the literature.

Report of a case of RAVEN, hair heterochromia and autism in the setting of FGFR2 mutation.

A newborn presented with extensive rounded and velvety epidermal nevus (RAVEN) with a genetic study of the cutaneous lesions revealing a heterozygous mutation in FGFR2 (p.Cys382Arg). By 2 years of age, the patient developed hair heterochromia and autism spectrum disorder. Although RAVEN was initially associated with fibroblast growth factor 3 (FGFR3) mutations, three cases of RAVEN have been identified with mutations in FGFR2 (p.Ser252Trp) and one case of linear keratinocytic epidermal nevi has been identified with the same mutation as the mutation identified in our patient. This strongly supports the pathogenic role of these mutations.

Sebaceous nevus of Jadassohn: review and clinical-surgical approach.

BACKGROUND: Nevus sebaceous of Jadassohn is defined as a rare congenital malformation characterized as a non-hereditary hamartoma of the adnexal structures of the skin. Its etiology is not yet well understood, but it is believed to be related to post-zygotic mutations in the HRAS, NRAS and KRAS genes. OBJECTIVE: To describe the clinical manifestation of nevus sebaceous, as well as the main management techniques addressed in the medical literature. Moreover, the present study discusses a case report of a congenital linear nevus in the left retroauricular region found in a male patient, without extracutaneous manifestations. METHOD: A narrative review of the literature was carried out. DISCUSSION: Nevus sebaceous occurs as lesions with a linear or oval appearance, with a smooth or verrucous texture, generally alopecic and with very variable color. Moreover, nevus sebaceous is one of the components of the so-called linear nevus syndrome or Schimmelpenning-Feuerstein-Mims syndrome, which is associated with multisystemic complications. The treatment of the lesions is still controversial; however, most experts indicate surgical excision as the most frequently adopted treatment method, in addition to multidisciplinary follow-up when the diagnosis of Schimmelpenning-Feuerstein-Mims syndrome is established. CONCLUSION: The linear nevus syndrome constitutes a rare manifestation; however, its diagnosis should be considered in children born with nevus sebaceous. There is no consensus yet on the best therapy, but surgical removal has shown to be a viable option.

Inflammatory linear verrucous epidermal nevus (ILVEN) encompasses a spectrum of inflammatory mosaic disorders.

BACKGROUND: Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disease characterized by pruritic erythematous scaly plaques distributed along the lines of Blaschko. Two cases of ILVEN with CARD14 mutations and one case with a GJA1 mutation have been previously reported. OBJECTIVE: To elucidate the genetic cause of a cohort of patients diagnosed based on clinical and histopathological evaluation with ILVEN. METHODS: We recruited patients diagnosed with ILVEN based on clinical and histopathological criteria. Exome sequencing of affected skin with or without blood/saliva was performed and germline and somatic pathogenic variants were identified. RESULTS: Five patients were enrolled. All had skin lesions from birth or early childhood. Two patients developed psoriasis vulgaris after the diagnosis of ILVEN. The first had a germline heterozygous CARD14 mutation and a post-zygotic hotspot mutation in KRT10. The histopathologic evaluation did not show epidermolytic hyperkeratosis. The second had a post-zygotic hotspot mutation in HRAS. Her ILVEN became itchy once psoriasis developed. One patient was re-diagnosed with linear porokeratosis based on a germline mutation in PMVK and a post-zygotic second-hit mutation. Two patients were re-diagnosed with congenital hemidysplasia with ichthyosiform nevus and limb defect nevus based on germline NSDHL mutations. CONCLUSION: ILVEN is a clinical descriptor for a heterogenous group of mosaic inflammatory disorders. Genetic analysis has the potential to more precisely categorize ILVEN and permits pathogenesis-directed therapies in some cases.

A case of inflammatory linear verrucous epidermal nevus successfully treated with Brodalumab.

Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare type of epidermal nevus, commonly arising in childhood. We present a case of a 13-year-old female with Blaschkoid psoriasiform plaques extending from her left foot to the scalp, sparing the right side of the body. While treatment options historically show variable success, we trialed an IL-17a receptor inhibitor as studies have shown increased levels of IL-17 receptor expression in ILVEN keratinocytes. At both 3 and 6 months after treatment initiation there was found to be significant improvement. We propose brodalumab as an effective treatment option for widespread ILVEN.