Nevus sebaceous revisited

Facial Soft Tissue Lesions in Children

Facial soft tissue lesions in children are often classified based on their structure or cellular origin and can be benign or malignant. This review focuses on common facial soft tissue lesions in children, their clinical morphology, natural history, and medical and surgical management, with an emphasis on those considerations unique to soft tissue lesions present at this anatomic site.

Rate of Benign and Malignant Secondary Tumors Associated With Nevus Sebaceous: A Systematic Review and Meta-Analysis

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.

Schimmelpenning-Feuerstein-Mims syndrome with orbital choristoma and KRAS mutation: a current review and novel case report

INTRODUCTION

Schimmelpenning-Feurstein-Mims Syndrome (SFMS) is a rare neurocutaneous disorder. Herein, we describe a novel case and review the phenotypic spectrum and molecular findings of SFMS from an ophthalmology perspective.

METHODS

Clinical case including presentation, management, pathology, and genetic analysis is described. A literature search on Schimmelpenning-Feuerstein-Mims and its synonyms, Linear nevus sebaceous syndrome, Organoid nevus syndrome, Jadassohn nevus phacomatosis, and Solomon syndrome, was conducted. An updated review and description of published cases with identified genetic mutations are described.

RESULTS

A 13-year-old boy with SFMS presented with acute right eye pain and an enlarging orbital mass. Excisional biopsy of the mass revealed an orbital choristoma. Genetic analysis of the orbital tumor confirmed a KRAS c.35 G>A, p.G12D mutation. A literature search revealed 19 cases of SFMS with mutations in the RAS-pathway. KRAS, HRAS, and NRAS mutations were identified in 74%, 21%, and 5% of patients, respectively. Ophthalmic pathology was seen in 83% of patients. Systemic findings varied and involved the skin, central nervous system, and eyes most commonly.

DISCUSSION

SFMS, a rare neurocutaneous disorder, results from postzygotic mosaic mutations in the RAS/MAPK pathway. Patients present with various systemic findings and ophthalmic manifestations occur in most cases. This is the first case description of a KRAS mutation identified in an orbital choristoma in SFMS. The disease is described under various names in the literature, and we propose that all syndromic cases with mosaic RAS mutations be reported under the eponym, SFMS.

Managing a Misdiagnosed Case of Nevus Sebaceous

A male patient in his early 20s presented to our outpatient clinic, having previously been misdiagnosed and unsuccessfully treated as a case of viral warts. Dermoscopic and histopathological evaluations revealed characteristic features of the nevus sebaceous. The lesion was eventually treated with an erbium-doped yttrium aluminum garnet (Er:YAG) laser after the patient declined surgical excision. Nevus sebaceous often presents with verrucous surfaces that make misdiagnosis common. A correct diagnosis is crucial due to potential neoplastic transformations. Histopathological analysis is essential for both the confirmation of disease and the exclusion of malignancy. Full-thickness surgical excision remains the preferred treatment.

Case Report: Leathery black plaque on the temple and scalp

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.

Basal cell carcinoma arising within nevus sebaceous on the right scalp in a 55-year-old male: A case report and review of literature

We report here a case of nevus sebaceous in a 55-year-old male, who presented with a 50-year history of an asymptomatic swelling in his right scalp. The solitary, yellowish, expansile plaque over the scalp gradually became lobulated and turned dark-pigmented with spontaneous bleeding, itching discomfort, and occasional ulceration after scratching. The male's clinical presentation and histopathological findings were compatible with basal cell carcinoma arising in nevus sebaceous. At present, 5-aminolevulinic acid photodynamic therapy (ALA-PDT) emerges as a novel treatment modality which has proved safe and effective. In this case, three sessions of photodynamic therapy in combination with surgical excision were performed, leaving mild pigmentation within 3 weeks. The patient showed good cosmetic outcome, minimal scarring on the right scalp without further complications, disease recurrence or metastasis after ALA-PDT within six months.

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.

Metastasis of a basosquamous carcinoma arising in a nevus sebaceus

Nevus sebaceus (NS) is a congenital hamartoma of skin structures including the epidermis, sweat sebaceous glands, and hair follicles. It is known that secondary tumors can occur in NS. However, secondary metastatic malignancies are rare. Basosquamous carcinoma (BSC) is an aggressive type of basal cell carcinoma (BCC) characterized by squamous differentiation. Herein, we report a case of metastatic BSC that developed in a 73-year-old male with NS. The clinical presentation of this patient was that of an ulcerative nodule developing in a longstanding plaque-like lesion consistent with NS. Histopathological examination revealed characteristic features of BCC with some areas of squamous differentiation in addition to the structure of a typical NS. Immunohistochemical expression of Ber-EP4, AE1/AE3, and epithelial membrane antigen helped to make the diagnosis of BSC.

Noninvasive imaging exploration of phacomatosis pigmentokeratotica using high-frequency ultrasound and optical coherence tomography: Can biopsy of PPK patients be avoided?

BACKGROUND

Phacomatosis pigmentokeratotica (PPK) is a distinct and rare type of epidermal nevus syndrome characterized by coexisting nonepidermolytic organoid sebaceous nevus (SN) with one or more speckled lentiginous nevi (SLN). Atypical nevi including compound Spitz and compound dysplastic may manifest within regions of SLN. Patients with PPK, or similar atypical nevus syndromes, may be subject to a significant lifetime number of biopsies, leading to pain, scarring, anxiety, financial burden, and decreased quality of life. The current literature includes case reports, genetics, and associated extracutaneous symptoms of PPK, but use of noninvasive imaging techniques have not been explored. We aim to investigate the value of high-frequency ultrasound (HFUS) and optical coherence tomography (OCT) in discriminating morphological features of pigmented lesions and nevus sebaceous within one patient with PPK.

MATERIALS AND METHODS

Two modalities, (1) HFUS imaging, based on acoustic properties and (2) OCT imaging, based on optical properties, were used to image a patient with PPK. Benign pigmented lesions, which may raise clinical suspicion for significant atypia, and nevus sebaceous, were selected on different areas of the body to be studied.

RESULTS

Five pigmented lesions and one area of nevus sebaceous were imaged and analyzed for noninvasive features. Distinct patterns of hypoechoic features were seen on HFUS and OCT.

CONCLUSION

HFUS provides a deep view of the tissue, with ability to differentiate gross structures beneath the skin. OCT provides a smaller penetration depth and a higher resolution. We have described noninvasive features of atypical nevi and nevus sebaceous on HFUS and OCT, which indicate benign etiology.

Malignant Melanoma Arising in a Prolific Nevus Sebaceus With Colonization of Trichoblastoma

ABSTRACT

Nevus sebaceus (NS) is a cutaneous hamartoma typically found on the head and neck, with a prevalence of 0.3% in newborns. Most NS are quiescent; however, benign and malignant lesions have been reported to arise within these nevi. Malignant transformation is not common but mainly includes basal cell carcinoma and squamous cell carcinoma. Malignant melanoma arising in NS is exceedingly rare, with only 2 previously documented cases. In this article, we report the first case of malignant melanoma arising in a NS in a 68-year-old man in the United States.

Atypical Nevus Sebaceus at an Unusual Location Treated with Carbon Dioxide Laser: A Case Report

Nevus sebaceus (NS) or organoid nevus is an epidermal nevus comprising predominantly sebaceous glands with a prevalence of approximately 0.3% of the newborns. The initial clinical manifestations of NS are single or less commonly multiple yellowish patches with overlying alopecia, usually confined to the scalp. However, it can also appear on the face, preauricular area, and the neck. During puberty, skin lesions will turn into round or linear verrucous plaques accompanied with an increase in number due to the influence of androgens. As they progress, about 20% of the NS cases might turn into secondary tumors which can be benign or malignant (in 2.5% cases). NS can manifest as atypical lesions and may also arise on areas other than its predilection sites. A case of a lesion presented on an atypical location of an 18-year-old male patient treated with carbon dioxide (CO₂) laser was reported. Physical examination revealed skin-colored and blackish-brown papules arranged in groups on the left side of the patient's chest. Histopathological examination on a sample taken from one of the skin lesions on the chest showed hyperkeratosis, acanthosis, papillomatosis, and sebaceous hyperplasia, confirming the diagnosis of NS. The patient was treated with CO₂ laser, and clinical improvements were observed. Histopathological examination of NS is not routinely performed; however, it should be carried out when the lesion is atypical and presented at an unusual location, or there is a suspicion of malignancy.

Malignant transformation of nevus sebaceous to basal-cell carcinoma: Case series, literature review, and management algorithm

Nevus sebaceous (NS) is a common congenital hamartoma of the skin composed predominantly of sebaceous glands. Although most NS are benign skin tumors, malignant transformations have been reported. There is still controversy about the lifetime risk of malignant degeneration and precise surgical criteria. This study reports cases of malignant degeneration and suggests a surgical treatment algorithm. The medical records of patients with basal-cell carcinoma (BCC) arising from NS between January 2001 and January 2021 were retrospectively reviewed. Patient demographics including lesion location, and tumor size were investigated. The symptoms, histological findings before and after excision, complications, and recurrence during 2-year follow-up periods were investigated. Ten patients were identified with BCC arising from NS lesions. All patients were female and the mean age was 52.11 years. All patients complained of sudden morphological changes, the most common type being rapid color changes. Two cases had histological findings that showed a miss-match between punch biopsy and excisional biopsy results. No recurrence was detected 2 years after surgeries in any patients. Cases after third stage, especially in over 40 years who report morphologic changes, should undergo total surgical excision as the first approach, with strong suspicion of malignant degeneration.

Trichilemmoma Arising in a Sebaceous Nevus Successfully Treated with Cryotherapy

Nevus sebaceous of Jadassohn (NSJ) is a benign congenital hamartoma composed of follicular, adnexal appendages and epidermal hyperplasia. Various secondary neoplasms, mostly adnexal in origin, can arise within nevus sebaceous. We report the case of a 16-year-old female who had NSJ associated with trichilemmoma, which was successfully treated with cryotherapy. We found cryotherapy to be an effective, satisfactory therapy, with acceptable cosmetic results, especially for patients who have visible lesions that can be easily followed.

[Benign skin neoplasms in children]

There are many different types of skin neoplasms in children and most are benign. Dermatologists should be able to differentiate between the various types of benign skin neoplasms and be able to recommend optimal treatment to concerned patients. Surgical removal of benign skin neoplasms is often the only treatment option. The aim of this paper is to provide a general overview of epidermal lesions (e.g., inflammatory linear verrucous epidermal nevus [ILVEN], nevus sebaceous), tumors of the epidermal appendages (e.g. pilomatrixoma), cutaneous neoplasms (e.g. angiofibroma), fibromatoses (e.g., knuckle pads), tumors comprised of fat, muscle, or bone tissue (e.g., osteoma cutis, subungual exostosis), epidermal cysts and pseudocysts, and pathologic fibrosis reactions after dermal injury (keloid). Scientific data are scarce and only in the last decade has it been possible to perform histopathological examinations and genetic studies together with detailed phenotyping to gain new understanding of the pathogenetic mechanisms.

Identification of a recurrent mosaic KRAS variant in brain tissue from an individual with nevus sebaceous syndrome

Nevus sebaceous syndrome (NSS) is a rare, multisystem neurocutaneous disorder, characterized by a congenital nevus, and may include brain malformations such as hemimegalencephaly or focal cortical dysplasia, ocular, and skeletal features. It has been associated with several eponyms including Schimmelpenning and Jadassohn. The isolated skin lesion, nevus sebaceous, is associated with postzygotic variants in HRAS or KRAS in all individuals studied. The RAS proteins encode a family of GTPases that form part of the RAS/MAPK signaling pathway, which is critical for cell cycle regulation and differentiation during development. We studied an individual with nevus sebaceous syndrome with an extensive nevus sebaceous, epilepsy, intellectual disability, and hippocampal sclerosis without pathological evidence of a brain malformation. We used high-depth gene panel sequencing and droplet digital polymerase chain reaction (PCR) to detect and quantify RAS/MAPK gene variants in nevus sebaceous and temporal lobe tissue collected during plastic and epilepsy surgery, respectively. A mosaic KRAS c.34G > T; p.(Gly12Cys) variant, also known as G12C, was detected in nevus sebaceous tissue at 25% variant allele fraction (VAF), at the residue most commonly substituted in KRAS. Targeted droplet digital PCR validated the variant and quantified the mosaicism in other tissues. The variant was detected at 33% in temporal lobe tissue but was absent from blood and healthy skin. We provide molecular confirmation of the clinical diagnosis of NSS. Our data extends the histopathological spectrum of KRAS G12C mosaicism beyond nevus sebaceous to involve brain tissue and, more specifically, hippocampal sclerosis.

Localized hair loss in infancy: a review

PURPOSE OF REVIEW

The current review will address the different causes of localized hair loss in infancy. The data presented here will provide clinicians with the latest understanding of different disorders leading to localized hair loss and will provide recommendations for further management of infants who present with alopecia.

RECENT FINDINGS

Localized hair loss in infancy is common, but its underlying causes vary greatly. Alopecia in infants can be categorized into congenital, genetic, inflammatory, mechanical, and physiologic causes. Decisions regarding further management are complex, as they often involve not only cosmetic concerns, but also work-up of possible systemic medical issues related to hair loss.

SUMMARY

Clinicians must be able to distinguish between the different causes of infantile hair loss so that appropriate work-up and further management can be pursued. Factors such as physical appearance, timing of presentation, dermoscopic exam, histopathology, and associated systemic features can help lead clinicians to the correct diagnosis in the case of an infant with localized alopecia.

Secondary Tumor Arising in a Nevus Sebaceous

Introduction. Nevus sebaceous is a rare congenital hamartoma, composed of epidermis, sebaceous glands, sweat glands and hair follicles. It is possible to develop secondary tumors in the area of nevus sebaceous during the lifetime, most often after puberty. Secondary lesions are most often benign, while malignant lesions may occur but significantly less frequently.

Case report. We present the case of a 21-year-old patient who came for an examination due to the appearance of a nodule in the area of a yellowish lesion on the head. The yellowish lesion was present since birth, and the nodule appeared about a year before. The dermoscopic examination of the lesion was nonspecific. The final diagnosis of eccrine poroma as a secondary lesion in nevus sebaceous was made by pathohisto-logical analysis.

Conclusion. Every secondary tumor in nevus sebaceous deserves full attention, with either close follow up, or excision with pathohistological analysis.

An updated review of the sebaceous gland and its role in health and diseases Part 2: Pathophysiological clinical disorders of sebaceous glands

Sebaceous glands are sebum-secreting components of pilosebaceous units. In the second of this two-part series, we review the pathologies in which sebaceous glands are primarily and secondarily implicated. They are primarily involved in steatocystoma simplex and multiplex, sebaceous gland hyperplasia, sebaceoma, sebaceous adenoma, sebaceous carcinoma, nevus sebaceus, and folliculosebaceous cystic hamartoma. Sebaceous glands are secondarily involved in acne vulgaris, seborrheic dermatitis, and androgenic alopecia. Steatocystoma multiplex is a benign congenital anomaly presenting as yellow cysts primarily on the upper body. Sebaceous gland hyperplasia is characterized by yellow, telangiectatic papules with a central dell, and it can be treated with topical retinoids or surgical excision. Sebaceoma clinically presents on the head and neck region as a skin-colored nodule and can be distinguished by immunohistochemistry. Stains used in the diagnosis of sebaceous adenoma and carcinoma include epithelial membrane antigen and adipophilin immunoperoxidase. Surgical excision is the preferred treatment for sebaceoma, sebaceous adenoma, and sebaceous carcinoma. Excision is not always indicated for nevus sebaceus. Folliculosebaceous cystic hamartoma is a relatively rare condition exhibiting both epithelial and mesenchymal components. Patients with acne vulgaris commonly present with papules of closed and open comedones displaying hypercornification. Seborrheic dermatitis presents as sharply demarcated yellow or red patches or plaques; antifungal agents, corticosteroids, and combination antifungal/anti-inflammatory therapies are common treatment modalities. As a result of hair follicle miniaturization, females with androgenic alopecia present with diffuse hair thinning, while men tend to present with balding and hairline recession.

Ultrasound Imaging of Nevus Sebaceous of Jadassohn

Nevus sebaceous of Jadassohn (NSJ) is a cutaneous hamartoma commonly found in the scalp and face and more frequent in children. Clinically, it presents as a yellowish and hairless plaque. In later stages, the NSJ can develop secondary tumors, including skin cancer. We reviewed the ultrasound characteristics of 9 patients (67% female; mean age, 3 years) with NSJ at 18 and 70 MHz. The ultrasound analysis covers the data on the location, thickness, echo structure, and vascularity. The provision of the ultrasound patterns of NSJ can support early diagnosis, avoid unnecessary biopsies, and support monitoring.

Four pediatric cases of secondary neoplasms arising in nevus sebaceous

Secondary neoplasms of epidermal adnexal origin have been reported to develop into nevus sebaceous (NS), mainly in adulthood but rarely in children. Four cases of secondary neoplasms were identified in 413 children of nevus sebaceous from 2015 to 2019 by our department, accounting for 1% of all cases. We here report the clinical, dermoscopical, and histopathological features of these tumors, including syringocystadenoma papilliferum (SCAP), pilomatricoma, trichilemmoma, and basal cell carcinoma (BCC). We recommend prophylactic excision of nevus sebaceous before puberty, not only because of the cosmetical disfigurement but also due to the risk of malignant transformation.

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.

Sebaceous Nevus of the Scalp

Excisions of scalp nevus sebaceous (NS) presents a unique challenge due to limited soft tissue laxity, hair-bearing skin, and convex surfaces which often leave the surgeon and patient underwhelmed with the reconstructive outcome. In this study, the authors conducted an institutional review board-approved retrospective review of patients who underwent excision of pathologically proven scalp primary NS from 2003 to 2017 at our institution to better define the reconstructive outcomes and options for treatment of pediatric scalp NS. 92 patients were included in the study, 54 males (58.7%) and 38 females (41.3%). The average age at surgery was 7.24 years (0.5-16.0; SD 4.7). Local tissue undermining/galeal scoring with primary closure (LTUGS) was used for lesions with average surface area of 3.6 cm, rotational or transposition flaps (RF/TF) for lesions averaging 4.3 cm, completed serial excision for lesions averaging 13.9 cm, and tissue expansion (TE) for lesions averaging 21 cm (P <0.001). One or more poor outcomes were experienced by 35 patients (38%), with a significant difference between the surgical groups; LTUGS 37.2% (29/78), RF/TF 60% (3/5), serial excision 100% (3/3), TE 0% (0/6) (P = 0.022). Univariant binary regression analysis within the LTUGS and RF/TF groups showed that lesion size was a significant predictor of poor outcomes (P = 0.012). All specimens in this study were negative for carcinoma. Therefore, most pediatric nevus sebaceous of the scalp can be managed by a single-phase procedure though risk of poor outcomes increase with nevus size with high rates of poor outcomes even with small lesions.

Lichen Planopilaris Developing at the Margins of a Sebaceous Nevus of Jadassohn: Co-existence or Etiologic Association?

Sebaceous nevus (SN), is a skin hamartoma, combining a variety of epidermal, follicular, sebaceous, and apocrine abnormalities. Although usually present at birth, it may become apparent later in life appearing as a yellowish-brown, verrucous plaque with alopecia. SN is implicated with secondary tumors arising on the hairless plaque during the adulthood. Lichen planopilaris is a common, primary lymphocytic scarring alopecia of unknown etiology, characterized by lichenoid/interface perifollicular lymphocytic infiltrate occurring at the level of the infundibulum and the isthmus. Here, we present a case of a 48-year-old Caucasian male with lichen planopilaris lesions developing at the periphery of a preexisting SN. Our case raises the question, whether the development of lichen planopilaris was coincidental, or is it indicative of an etiologic association between the lichen planopilaris and SN.

The color of skin: yellow diseases of the skin, nails, and mucosa

The colors reflected from the skin are important indicators of dermatologic and systemic disorders. Incident light is subject to absorption by chromophores in the skin and scattering. Chromophores associated with yellow light reflection include the carotenoids and bilirubin. Various pathophysiologic mechanisms associated with these and other chromophores manifest with a yellow hue on examination. This review describes these mechanisms and the clinical features of yellow skin disorders by morphology. A brief summary of the differential diagnosis, laboratory investigations, and treatments are presented. Yellow skin disorders are a heterogenous group composed of abnormalities in keratin, elastic and connective tissue, lipid metabolism, and other states of metabolic, inflammatory, or organ dysfunction. Patients will present through different routes, and skin disease may precede or follow systemic disease. Dermatologists have an essential role in identifying those with malignant or systemic associations to ensure early diagnosis and treatment.

Is Schimmelpenning Syndrome Associated with Intracranial Tumors? A Case Report

Schimmelpenning syndrome is a rare, well-defined constellation of clinical phenotypes associated with the presence of nevus sebaceous and multisystem abnormalities most commonly manifested as cerebral, ocular, and skeletal defects [<xref ref-type="bibr" rid="ref1">1</xref>]. A single nucleotide mutation in the HRAS or KRAS genes resulting in genetic mosaicism is responsible for the clinical manifestations of this syndrome in the majority of cases. We report a case of an adolescent boy with Schimmelpenning syndrome with a multifocal pilocytic astrocytoma. No HRAS or KRAS gene mutations were noted in the tumor on genetic sequencing. However, glial tumors have been associated with genetic mutations of RAS upregulation, which may imply a common pathway.

Common Neonatal Skin Lesions: Melanocytic Nevi, Pigment Alterations, and Nonmelanocytic Nevi

Birthmarks are common in the healthy population and are generally harmless. Certain presentations, however, raise concern for associated syndromes or potential complications. It is important for pediatricians to be familiar with both harmless and potentially concerning birthmarks. This article discusses congenital melanocytic nevi, café-au-lait macules, hypomelanotic macules, nevus depigmentosus, nevus anemicus, epidermal nevi, and nevus sebaceous, including potential syndromes and complications. [Pediatr Ann. 2019;48(1):e23-e29.].

Dermatoscopy of Common Lesions in Pediatric Dermatology

The use of dermatoscopy to assist in the diagnosis of a variety of proliferative, pigmentary, inflammatory, infectious, congenital, and genetic cutaneous and skin appendage disorders is constantly increasing, as it is effective, affordable, noninvasive, and quick to perform.

Rare desmoplastic trichilemmoma associated with sebaceous nevus

Nevus sebaceous of Jadassohn is a congenital hamartoma that usually affects the scalp and face. Several benign or malignant neoplasias may develop in the lesion and the most common are trichoblastoma, syringocystadenoma papilliferum, and basal cell carcinoma. Trichilemmoma is a benign solid tumor originating from external sheath cells of pilosebaceous follicles. When it is characterized by a central zone of desmoplasia, it is called desmoplastic trichilemmoma. We report a case of a 58-year-old patient who developed a tumor in a sebaceous nevus. We performed a total excision of the lesion. Histopathological diagnosis was compatible with desmoplastic trichilemmoma. Our literature review reveals that the occurrence of trichilemmoma desmoplastic is unusual. Moreover, it can mimic an invasive carcinoma on histological and clinical examinations. This fact confirms the importance of reporting the occurrence of this rare cancer in a nevus sebaceous of Jadassohn.

Management of naevus sebaceous: a national survey of UK dermatologists and plastic surgeons

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.

Giant proliferating trichilemmal cyst arising from a nevus sebaceus growing for 30 years

Nevus sebaceus of Jadassohn, a congenital cutaneous hamartoma, has the potential to develop into various epidermal adnexal-origin neoplasms. While the most common neoplasms are trichoblastoma or syringocystadenoma, proliferating trichilemmal cysts are exceptionally rare. We report a case of a 63-year-old Cuban male with a giant proliferating trichilemmal cyst arising from a nevus sebaceus on the right shoulder which had been growing for 30 years. Proliferating trichilemmal cysts arising from nevus sebaceus cases are difficult to diagnose clinically and histologically as they are very rare and have not been defined by exact diagnostic criteria. Our case creates awareness of this particular tumor in nevus sebaceus and shares clinical and histological diagnostic information that can be used to make a proper diagnosis.

Dermoscopic Analysis of Nevus Sebaceus of Jadassohn: A Study of 13 Cases

BACKGROUND

Nevus sebaceus of Jadassohn (NSJ) is a complex cutaneous hamartoma with various clinical appearances.

AIM

To describe different dermoscopic patterns of this nevus according to its evolutionary stages.

METHODS

This was an analytical study of NSJ carried out in the Department of Dermatology at the University Hospital Hassan II, Fez, Morocco.

RESULTS

Thirteen patients with a NSJ were enrolled in the study. Elevated verrucous plaques were noticed in 9 patients, homogeneous tumors were described in 2 NSJ, an alopecic patch was found in 1 case, and we had 1 case of malignant transformation into basal cell carcinoma. The dermoscopic aspects of NSJ described in our study were yellowish or brown globules aggregated in clusters on a yellow background. This pattern was significantly related to the first stage of an alopecic patch (p = 0.001). Whitish-yellow lobular aspect and grayish papillary appearance were significantly related to verrucous plaques (p = 0.003). Homogeneous yellow-whitish pattern was related to nodules (p = 0.005).

CONCLUSION

The establishment of specific dermoscopic features of NSJ according to its evolutionary stages is important for its diagnosis and especially its monitoring in order to detect malignant transformation.