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Linear nevus sebaceous syndrome (LNSS) is a neurocutaneous syndrome associated with systemic complications that involve multiple organs, including the skin, central nervous system, eyes, and skeleton. LNSS is considered to be caused by mosaic RAS gene mutation. In this report, we present an autopsy case of LNSS in a Japanese boy. The affected neonate had hydrops fetalis and was born at 28 weeks and 4 days of gestation, weighing 2104 g. He had bilateral inverted eyelids, verrucous linear nevus separated along Blaschko's line, myocardial hypertrophy, and pharyngeal constriction, and underwent intensive treatment in NICU for arrhythmia, hydrocephalus, and respiratory distress. The hydrocephalus progressed gradually and he died at the age of 181 days, 12 days after a sudden cardiac arrest and recovery. KRAS G12D mutation was found in a skin biopsy specimen but not in blood cells, suggesting a postzygotic mosaicism. Autopsy revealed novel pathological findings related to LNSS, including intracranial lipomatous hamartoma and mesenteric lymphangioma, in addition to previously reported findings such as multicystic dysplastic kidney. There was the limited expression of mutated KRAS protein in kidneys., (© 2024 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Competing Interests: Competing interests: None declared.

Linear nevus sebaceous syndrome (LNSS) is a rare neurocutaneous syndrome part of the epidermal nevus syndromes group, characterized by the presence of sebaceous nevi and other extracutaneous lesions genetically related to RAS family gene mutations. Sialadenoma papilliferum (SP) is a rare benign intraoral neoplasm which is usually BRAF or HRAS mutated. We report a case of a young female girl diagnosed with a LNSS who developed a SP which had a KRAS mutation. This is the first case of SP with a KRAS mutation in the context of a LNSS., (Copyright © 2024 Società Italiana di Anatomia Patologica e Citopatologia Diagnostica, Divisione Italiana della International Academy of Pathology.)

Syringocystadenocarcinoma papilliferum (SCACP) is a rare and aggressive malignant adnexal tumor originating from apocrine or pluripotent appendageal glands, often associated with a preceding syringocystadenoma papilliferum (SCAP) or nevus sebaceus (NS). This systematic review rigorously examines SCACP through an analysis of 78 cases documented between 1980 and 2024. The study aims to provide a comprehensive review of the clinical manifestations, diagnosis, treatment modalities, and outcomes associated with SCACP, while also reappraising its associations, particularly with NS. SCACP predominantly affects older adults, with an average age of 66.3 years and a slight male predominance, commonly presenting as ulcerated nodules or plaques on the scalp. This review highlights the aggressive nature of SCACP, evidenced by significant rates of metastasis and recurrence. Treatment is primarily surgical, with Mohs micrographic surgery offering potential benefits in terms of margin control and cosmetic outcomes. The association of SCACP with NS is critically evaluated, suggesting a complex etiopathogenesis and underscoring the importance of recognizing this association for timely diagnosis and management. Our review also briefly discusses potential pitfalls faced by clinicians in the diagnosis of SCACP. Our findings emphasize the need for standardized treatment protocols and further research into targeted therapies to improve patient outcomes in SCACP., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cerebriform sebaceous naevus (CSN) is a rare morphological sebaceous naevus variant and challenging to diagnose prenatally due to its flat, smooth and waxy appearance and lack of association with extracutaneous manifestations.A multigravida was referred to our tertiary obstetric unit at 24 weeks of gestation for evaluation of fetal auricular lesions. We were able to further characterise the lesions via serial obstetric ultrasound imaging with the aid of three-dimensional (3D) technology. Although the precise diagnosis prenatally was uncertain, the use of 3D technology allowed the reconstruction of the fetal cutaneous lesions for multidisciplinary assessment to facilitate the development of a neonatal management plan. The diagnosis of CSN was made postnatally on biopsy., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Nevus sebaceous (NS) is a rare congenital skin lesion affecting approximately 0.3% of all newborns. Although benign, NS lesions can harbor malignant secondary tumors. The published rate of development of these malignant tumors varies. This meta-analysis aimed to identify the rate of malignant and benign secondary neoplasms occurring in NS., Methods: A literature search was conducted using PubMed, Embase, and Web of Science from inception to April 2023. Eligible studies reported incidence or risk of secondary neoplasms in patients with NS. Two independent reviewers screened studies, extracted data, and assessed the quality of included studies. The primary outcome was the pooled incidence of secondary neoplasms. Studies with sample sizes greater than 50 patients were eligible for meta-analysis using the random-effects model., Results: Twenty-eight studies were identified, 22 of which were eligible for meta-analysis. The overall rate of secondary neoplasms was 12.8% (95% confidence interval [Cl], 9.2%-17.6%). The rates of development of malignant and benign tumors were 2.4% (95% CI, 1.4%-4.1%) and 10.3% (95% CI, 7.5%-13.9%), respectively. The rate of development of basal cell carcinoma was 1.7% (95% CI, 0.9%-3.2%), whereas the rate of the development of syringocystadenoma papilliferum was 3.6% (95% CI, 2.5%-5.3%) and that if trichoblastoma was 2.6% (95% CI, 1.7%-3.8%)., Conclusions: Although the rate of development of malignant tumors within a primary NS lesion is low, it is not negligible. Prophylactic early excision remains a viable approach to prevent secondary malignant neoplasms, address cosmetic and functional complications, and preempt the need for complex reconstruction in the future. We propose that resection of NS lesions in childhood remains a reasonable first-line option in the appropriate patient keeping in mind that it may leave an undesirable scar., Competing Interests: Conflicts of interest and sources of funding: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Epidermal nevus sebaceous, commonly known as the nevus sebaceous of Jadassohn, is a congenital sebaceous hamartoma. It typically manifests as a single yellowish plaque across the head and neck and is composed of sebaceous glands. It commonly occurs during infancy and grows during puberty. Usually, it follows a benign course; however, in a few cases, it can be malignant. This is the case of a 13-year-old child with verrucous plaques on the temple and scalp., Case Report: We report the case of a 13-year-old boy with a steadily developing hyperpigmented verrucous plaque on the scalp and ipsilateral side of his face. A dermoscopic examination revealed ridges and fissures in a cerebriform pattern with yellowish-gray globules and a papillary appearance. Physical examination and laboratory tests revealed no abnormalities. Biopsies were taken from the scalp and temple area, and the findings were consistent with the diagnosis of nevus sebaceous. The patient was referred to a plastic surgeon for a staged excision., Conclusions: We describe a unique example of a sebaceous nevus that affected the scalp and ipsilateral side of the face. As this hamartomatous growth carries the risk of cancer development, a dermatologist must identify the condition and begin treatment before malignant transformation occurs. This example of multiple verrucous plaques is an exception., Competing Interests: No competing interests were disclosed., (Copyright: © 2024 Rusia K et al.)

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., (© 2024. The Author(s).)

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., (© 2023 Japanese Dermatological Association.)

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 KRAS G12V 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 KRAS G12V expression leads to disrupted excitation and inhibition balance. Transcriptional profiling after destabilization domain-mediated clearance of KRAS G12V in human neural progenitors and differentiating neurons identifies reversible functional networks underlying LNSS. Neurons expressing KRAS G12V show molecular changes associated with delayed neuronal maturation, most of which are restored by KRAS G12V 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., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Schimmelpenning-Feuerstein-Mims (SFM) syndrome is a neurocutaneous disorder that can affect many body systems. The principal and most characteristic anomalies are craniofacial naevus sebaceous in association with neurological, ocular and skeletal findings. The presence of vascular malformations in this condition is unusual; nevertheless, vascular malformations have been suggested by many authors to be part of the spectrum of the same disease. Few cases have been published on the association of SFM with lymphatic malformations. This syndrome is categorized as a mosaic RASopathy due to postzygotic mutations in the HRAS, KRAS or NRAS genes. These genes are involved in the RAF-MEK-ERK signalling pathway, which is activated by mutant cells, increasing cellular proliferation. These mutations have been found only in naevus sebaceous cells, and may be also the explanation for many of the associated pathologies. We report a case of an 18-year-old boy diagnosed with SFM syndrome associated with lymphatic malformation in the legs and agenesia of the inguinal lymph nodes. The lymphatic alterations were diagnosed by gammography of the legs. The genetic diagnosis was confirmed by the presence of a KRAS postzygotic mutation in naevus sebaceous cells of a skin specimen. Genetically confirmed cases of mosaic RASopathies should be used to more accurately characterize phenotypic presentations of this syndrome and develop a future therapeutic strategy, such as molecular targeted therapy., (© 2021 British Association of Dermatologists.)

Adult-onset inflammatory linear verrucous epidermal nevus (ILVEN) is an uncommon cutaneous disease compared to childhood-onset ILVEN. The typical histopathologic features are alternating parakeratosis and orthokeratosis with an absent granular layer underneath parakeratosis, in contrast to a thickened granular layer below the foci of orthokeratosis in psoriasiform epidermal hyperplasia. Herein, we present a 49-year-old woman with typical clinical and histopathologic characteristics of adult-onset ILVEN, including linear arrangement of thick scaly papules and plaques localized on the medial side of her right leg, ankle, and foot. Immunohistochemical studies included involucrin, Ki-67, and keratin-10. Compared to the staining pattern in psoriasis, the expression of involucrin in this case was of lower intensity and localized to upper epidermal layers with relatively less extensive staining beneath regions of parakeratosis as compared to orthokeratosis; Ki-67 showed lower basal layer proliferative activity; and keratin-10 showed a greater intensity of staining within suprabasal epidermis., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Linear nevus sebaceous syndrome (LNSS) is a rare genetic disease characterized by large linear sebaceous nevus typically on the face, scalp, or neck. LNSS could be accompanied by multisystem disorders including the central nervous system. Herein, we report gene mutational profile via whole exome sequencing of both lesional and non-lesional skin samples in a LNSS patient., Case Presentation: A 17-year-old girl presented with multisystem abnormalities, including large skin lesions, ocular disorders, abnormal bone development and neurological symptoms. A diagnosis of LNSS was established based on clinical manifestations, histopathological and imaging findings. The skin lesions were resected and no recurrence was noted at the time of drafting this report. Whole exome sequencing of genomic DNA revealed the following 3 mutations in the lesions of the index patient: KRAS (c.35G > A, p.G12D), PRKRIR (c.A1674T, p.R558S), and RRP7A (c. C670T, p.R224W), but no mutation was found in the healthy skin and peripheral blood sample of the index patient, or in the blood samples of her parents and sibling. PCR-mediated Sanger sequencing of DNA derived from lesional skin sample of the index patient verified KRAS mutation, but not PRKRIR (c.A1674T, p.R558S) and RRP7A (c. C670T, p.R224W). None of the 3 mutations was found in Sanger sequencing in skin lesions of 60 other cases of nevus sebaceous patients., Conclusions: Our findings show the relevance of KRAS mutation to LNSS, providing new clues in understanding related genetic heterogeneity which could aid genetic counselling for LNSS patients.

Overgrowth syndromes are a large group of rare disorders characterized by generalized or segmental excessive growth. Segmental overgrowth syndromes are mainly due to genetic anomalies appearing during the embryogenesis and leading to mosaicism. The numbers of patients with segmental overgrowth with an identified molecular defect has dramatically increased following the recent advances in molecular genetic using next-generation sequencing approaches. This review discusses various syndromes and pathways involved in segmental overgrowth syndromes and presents actual and future therapeutic strategies., (© 2020 médecine/sciences – Inserm.)

Nevus sebaceus is a benign skin hamartoma of congenital onset that grows during puberty, and in adulthood can develop secondary benign and malignant neoplasms. The most common benign neoplasms occurring in nevus sebaceus are believed to be syringocystadenoma papilliferum, trichilemmoma, and trichoblastoma. A patient with nevus sebaceus developed not only syringocystadenoma papilliferum but also prurigo nodularis within her hamartomatous lesion; multiple biopsies were necessary to establish the diagnoses. Excision of the residual nevus sebaceus also revealed an apocrine cystadenoma, basaloid follicular proliferation, and sebaceoma. Also, it is important to select the appropriate biopsy site and size when evaluating a patient for secondary neoplasms within their nevus sebaceous. Indeed, more than one biopsy may be required if additional diagnoses are suspected.

Linear verrucous epidermal nevi (LVEN) are characterized by verrucous papules often coalescing into well-demarcated skin-colored or brown plaques following the lines of Blaschko. We present two new cases of LVEN with oral mucosa involvement and briefly discuss this very rare finding. In both cases, oral biopsies showed hyperkeratosis, acanthosis, and papillomatosis. Although several treatment modalities have been reported for the cutaneous lesions, there is no consensus for the management of oral lesions so far.

Background/aim: Verrucous epidermal nevi are cutaneous hamartomas with many clinical variants. Dermoscopic features of verrucous epidermal nevus have rarely been investigated. We aimed to identify dermoscopic findings of the entity which will facilitate the diagnostic process by reducing the use of invasive diagnostic methods., Materials and Methods: The study included the patients with histopathologically approved verrucous epidermal nevus. Clinical, dermoscopic, and histopathological features of the patients were retrospectively reviewed and the findings identified were recorded. Dermoscopic examination was performed with a polarized-light handheld dermoscope with 10-fold magnification., Results: The most common dermoscopic features were thick brown circles, thick brown branched lines, and terminal hairs. The most common vessel pattern was dotted vessels. Branched thick brown lines, brown globules, brown dots forming lines, serpiginous brown dots, white and brown exophytic papillary structures, fine scale, thick adherent scale, and cerebriform structures were the other findings., Conclusion: We observed many vascular and nonvascular dermoscopic findings which were not described previously for the entity. Dermoscopic examination of the verrucous epidermal nevi may lead to more reliable clinical interpretation and thus may reduce the need for histopathological investigation., (This work is licensed under a Creative Commons Attribution 4.0 International License)

Background: Postzygotic KRAS, HRAS, NRAS, and FGFR1 mutations result in a group of mosaic RASopathies characterized by related developmental anomalies in eye, skin, heart, and brain. These oculocutaneous disorders include oculoectodermal syndrome (OES) encephalo-cranio-cutaneous lipomatosis (ECCL), and Schimmelpenning-Feuerstein-Mims syndrome (SFMS). Here, we report the results of the clinical and molecular characterization of a novel cohort of patients with oculocutaneous mosaic RASopathies., Methods: Two OES, two ECCL, and two SFMS patients were ascertained in the study. In addition, two subjects with unilateral isolated epibulbar dermoids were also enrolled. Molecular analysis included PCR amplification and Sanger sequencing of KRAS, HRAS, NRAS, and FGFR1 genes in DNA obtained from biopsies (skin/epibulbar dermoids), buccal mucosa, and blood leukocytes. Massive parallel sequencing was employed in two cases with low-level mosaicism., Results: In DNA from biopsies, mosaicism for pathogenic variants, including KRAS p.Ala146Thr in two OES subjects, FGFR1 p.Asn546Lys and KRAS p.Ala146Val in ECCL patients, and KRAS p.Gly12Asp in both SFMS patients, was demonstrated. No mutations were shown in DNA from conjunctival lesions in two subjects with isolated epibubar dermoids., Conclusion: Our study allowed the expansion of the clinical spectrum of mosaic RASopathies and supports that mosaicism for recurrent mutations in KRAS and FGFR1 is a commonly involved mechanism in these rare oculocutaneous anomalies., (© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.)

Inflammatory linear verrucous epidermal nevus (ILVEN) is a chronic, a linear, or whorled array of inflammatory, following the lines of Blaschko. Treatment of ILVEN is challenging with numerous therapies of varying degrees of success reported. We present a case of ILVEN in a 5-year-old-boy, treated successfully with crisaborole 2% ointment. This brief report suggests that there may be additional cellular immunologic pathways responsible for the presentation of ILVEN that may be explained by management with crisaborole use., (© 2019 Wiley Periodicals, Inc.)

Nevus sebaceus (NS), also known as an organoid nevus, is a congenital skin hamartoma involving the pilosebaceous unit, epidermis, and adnexa, frequently occurring in the scalp area. During childhood, the lesion remains unchanged but may subsequently increase in size during puberty in response to hormonal release, with possible tumor development. We report a case of squamous cell carcinoma (SCC) development in an NS with histologic evidence of perineural involvement on the anterior central scalp of a 13-year-old adolescent girl. We also review the management and prognosis.

Schimmelpenning syndrome is a rare neurocutaneous disorder categorized as a mosaic RASopathy due to postzygotic HRAS or KRAS mutations. We report a 6-year-old girl diagnosed with Schimmelpenning syndrome due to a postzygotic KRAS G12D mutation. The patient had three atypical symptoms of Schimmelpenning syndrome: renovascular hypertension, congenital lipomatosis, and diabetes mellitus. The first two symptoms may overlap with phenotypes of other neurocutaneous syndromes or congenital lipomatous overgrowth syndrome due to mosaic RASopathies or other somatic mosaic mutations. We propose that impaired glucose tolerance was caused by KRAS mutation and a novel clinical phenotype of Schimmelpenning syndrome. Our study indicated that clinical diagnosis of Schimmelpenning syndrome or related conditions should be reorganized with genetic diagnosis of postzygotic mutation. Moreover, further accumulation of genetically proven cases with mosaic RASopathies should be used to more accurately characterize phenotypic presentations of this syndrome and develop a future therapeutic strategy, such as molecular-targeted therapy.

The co-existence of papular nevus spilus (PNS) and ipsilateral extracutaneous abnormalities involving peripheral nerves of the skin or muscles was originally described as "speckled lentiginous nevus syndrome". To avoid confusion with macular nevus spilus, the condition was recently re-named "papular nevus spilus syndrome". In addition to 14 published cases, we identified six new cases via a search of the worldwide literature. New diagnostic criteria are suggested: (1) presence of a PNS; (2) presence of a neurological or skeletal abnormality which is usually ipsilateral to the nevus; and (3) absence of a nevus sebaceus. According to current knowledge, PNS syndrome is a rather rarely occurring, sporadic disorder that can be considered to be part of a spectrum of mosaic RASopathies, which includes isolated PNS, isolated nevus sebaceus, PNS syndrome, Schimmelpenning syndrome, and phacomatosis pigmentokeratotica.

Schimmelpenning syndrome is a neurocutaneous disorder characterized by craniofacial nevus sebaceus that fall along embryonic cutaneous lines and tend to be associated with neurological, ocular, skeletal, and vascular abnormalities. We report a child with extensive nevus sebaceus of the scalp, face, and thorax and other unusual physical findings who was found to have a mosaic mutation of KRAS c.35G>A p.12D pathognomonic of Schimmelpenning syndrome.

A 17-year-old woman presented with moderately itchy, non-progressive, linearly arranged verrucous plaques over dorsum of left foot since early childhood. Two years ago, she developed slowly increasing, verrucous exophytic growth in posterior most aspect of linear verrucous plaque. One year ago, she also developed multiple, linearly arranged, fleshy plaques with surface crusting over lateral aspect of right leg extending to thigh. Biopsy from both verrucous lesion on left foot and fleshy plaque on right leg showed an exophytic growth with significant papillomatosis, neutrophils in stratum corneum, acanthosis and infiltration of papillary dermis with foamy macrophages that were CD 68 positive, features compatible with verruciform xanthoma (VX). Biopsy from linear verrucous plaque over left foot was consistent with inflammatory linear verrucous epidermal nevus (ILVEN). A diagnosis of segmental VX and VX overlying ILVEN was made., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

Verrucous nevus is a benign tumor showing a linear pattern on Blaschko lines. It is caused by mosaic mutations of the receptor FGFR3 gene. It manifests as an aesthetic disfigurement, but individuals even experience functional complications due to itchiness. Lesions may be localized or extended (giant). In our context, the scarcity of specialized centers in dermatology is a cause of diagnostic delay inducing the patient to undertake unsuitable therapies responsible for infectious or degenerative complications. We report the case of a 15-year old girl with a history of keratotic papules showing a linear pattern along the neck, the right upper limb, the flank since childhood. Histological examination confirmed the diagnosis of verrucous nevus.

Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare cutaneous disease that presents as linear psoriasiform plaques with associated prominent pruritus. The lesions commonly pre-sent on the legs with onset during childhood. Inflammatory linear verrucous epidermal nevus typically is refractory to treatment. Therapies range from topical treatments to lasers and surgical options. It is clinically and histopathologically similar to psoriasis, suggesting it may respond to established psoriasis treatments such as the excimer laser. We report the case of an otherwise healthy 20-year-old woman with dry, pruritic, red lesions on the right leg that had been present since infancy. Biopsy revealed psoriasiform hyperplasia with a verruciform surface. Multiple topical treatments including ablative CO 2 laser therapy showed no remarkable improvement. The patient was then treated with a UV 308-nm excimer laser and showed noticeable clinical improvement. Because of its clinical and histopathological similarities to psoriasis, we hypothesized that the excimer laser may be useful in the treatment of these lesions.

Naevus sebaceous (NS) is a congenital cutaneous hamartoma, which typically occurs on the head and neck. Historically, the treatment of choice was excision in infancy because of the potential for malignant transformation; however, recent studies suggest that this risk is < 1% and unlikely in childhood. We sent a questionnaire to UK dermatologists and plastic surgeons to investigate current management practice of NS. We found that almost a third of dermatologists still recommend excision for malignancy prevention, while over 90% of plastic surgeons consider excision, with 64% citing malignancy prevention as the reason. Plastic surgeons most commonly recommended excision in childhood, whereas dermatologists waited until adulthood. We have shown there is significant variation in practice across the UK in the management of naevus NS. It is important that patients across the UK receive the same standard of care, and therefore we advocate the development of evidence-based guidance for treatment of naevus NS., (© 2018 British Association of Dermatologists.)