The epidermal nevus syndromes: multisystem disorders

Unveiling the complexity of Schimmelpenning-Feuerstein-Mims syndrome: A comprehensive case study

Purpose

The purpose of this study was to report the comprehensively examined patient exhibiting oculocutaneous clinical features of Schimmelpenning-Feuerstein-Mims syndrome (SFMS).

Background

Schimmelpenning-Feuerstein-Mims syndrome (SFMS) is a rare phakomatosis characterized by the presence of sebaceous hamartomas on the skin along with extracutaneous abnormalities involving various neuroectodermal systems. The syndrome is typically sporadic and can originate from postzygotic mutations in genes implicated in the RAS signaling pathway (RAS proteins and their downstream pathways play pivotal roles in cell proliferation, differentiation, survival, and cell death): HRAS (11p15), NRAS (1p13), and KRAS (12p12). This case report involves a comprehensively examined patient exhibiting oculocutaneous clinical features of SFM, without neurological or involvement in other areas. Clinical and molecular diagnoses enable tailored monitoring of potentially affected organs and systems, involving a multidisciplinary approach by various medical specialists.

Conclusion and importance

The SFM is attributed to a pathogenic variant in KRAS gene. The molecular analysis in individuals suspected of SFMS involves identifying the somatic mutation in affected tissues and comparing it with non-affected tissues, such as mucosa or blood. Early detection and appropriate treatment of ophthalmological abnormalities associated with SFM are crucial to improving the quality of life and visual prognosis of affected individuals.

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.

Epidermal nevus syndrome with the mutation of PTCH1 gene and cerebral infarction: a case report and review of the literature

BACKGROUND

Epidermal nevus syndrome is a group of congenital neuroectodermal and/or mesodermal disorders characterized by the epidermal nevi in common association with cerebral, eye, skeletal, cardiovascular, and renal abnormalities. Epidermal nevus syndrome is a rare syndrome, and epidermal nevus syndrome with the mutation of PTCH1 gene and cerebral infarction is even rarer and has not been reported to the best of our knowledge.

CASE PRESENTATION

We report the case of a 10-month-old Chinese female patient who presented to our pediatric neurologic department, University of Wenzhou medical teaching Hospital, Hangzhou. She has mobility disorders on the right limbs and recurrent seizures. She had congenital disorder accompanied by brownish-black and verrucose plaques on the right side of the face as well as extensive brownish-black plaques and brown nevi on the right side of the trunk and the right arm. Epidermal nevus syndrome was diagnosed on the basis of her symptoms. Somatic sebaceous nevi and hypoplastic defects of skin, cerebra, eyes, skeleton, and cardiovascular and renal system were observed. However, in addition to the typical clinical characteristics, the patient also has a mutation (c.109G > T) in PTCH1 gene and cerebral infarction. We present a novel case report and literature review.

CONCLUSION

To our knowledge, epidermal nevus syndrome with a mutation of PTCH1 gene and cerebral infarction has not been reported previously. This case report may contribute to characterizing the phenotype of epidermal nevus syndrome, help clinicians be aware of the association of this condition with PTCH1 gene and cerebral infarction, raise clinical suspicion, and improve early therapy.

[The most common benign cutaneous neoplasms of the epidermis and appendages and their treatment]

Benign cutaneous neoplasms are well defined histologically with absence of all of the following features: architectural disorder, necrosis, cytologic atypia, and atypical mitotic figures. The clinical appearance of any neoplasm is a very important diagnostic factor. The classification of the lesion determines the therapeutic options. This article summarizes the clinical aspects and treatments of the most common benign tumors of the epidermis and its appendages.

Dermoscopic aspect of verrucous epidermal nevi: new findings

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.

Do you know this syndrome? Schimmelpenning-Feuerstein-Mims syndrome

Nevus sebaceous is the most common type of organoid epidermal nevus, often located on the face, following the Blaschko's lines and with alterations in the ipsilateral central nervous system. Distinct disorders can be distinguished by the type of association with epidermal nevus. Schimmelpenning-Feuerstein-Mims syndrome is a rare multisystem disorder characterized by sebaceous nevus associated with extracutaneous abnormalities affecting the brain, eyes and bones. We report the case of an 8-year-old female patient with a yellowish verrucous plaque on the left temporal area extending ipsilaterally to the cervical region, combined with cicatricial alopecia, periocular nodule, and epibulbar tumors.

Late onset epidermal nevus with hypertrichosis and facial hemihypertrophy

Epidermal nevus syndromes are rare conditions, characterized by different types of keratinocytic or organoid epidermal nevi in association with ocular, neurological, and skeletal manifestations. We present a case of late onset epidermal nevus with hypertrichosis and hemihypertrophy of face. Genetic analysis did not reveal presence of FGFR3 or PIK3CA mutations. The patient has features that cannot be categorized into the present well-known syndromes.

Multilineage somatic activating mutations in HRAS and NRAS cause mosaic cutaneous and skeletal lesions, elevated FGF23 and hypophosphatemia

Pathologically elevated serum levels of fibroblast growth factor-23 (FGF23), a bone-derived hormone that regulates phosphorus homeostasis, result in renal phosphate wasting and lead to rickets or osteomalacia. Rarely, elevated serum FGF23 levels are found in association with mosaic cutaneous disorders that affect large proportions of the skin and appear in patterns corresponding to the migration of ectodermal progenitors. The cause and source of elevated serum FGF23 is unknown. In those conditions, such as epidermal and large congenital melanocytic nevi, skin lesions are variably associated with other abnormalities in the eye, brain and vasculature. The wide distribution of involved tissues and the appearance of multiple segmental skin and bone lesions suggest that these conditions result from early embryonic somatic mutations. We report five such cases with elevated serum FGF23 and bone lesions, four with large epidermal nevi and one with a giant congenital melanocytic nevus. Exome sequencing of blood and affected skin tissue identified somatic activating mutations of HRAS or NRAS in each case without recurrent secondary mutation, and we further found that the same mutation is present in dysplastic bone. Our finding of somatic activating RAS mutation in bone, the endogenous source of FGF23, provides the first evidence that elevated serum FGF23 levels, hypophosphatemia and osteomalacia are associated with pathologic Ras activation and may provide insight in the heretofore limited understanding of the regulation of FGF23.

Epidermal nevus syndrome

Epidermal nevus syndrome (ENS) is an inclusive term for a heterogeneous group of congenital disorders characterized by the presence of epidermal nevi associated with systemic involvement. These disorders, as are all primary neurocutaneous syndromes, are neurocristopathies. The epidermal nevi that follow the lines of Blaschko and most systemic anomalies in skeletal, ocular, cardiovascular, endocrine, and orodental tissues, as well as lipomas, are due to defective neural crest. The most important and frequent anomaly in the brain in all forms of epidermal nevus syndromes (ENSs) is hemimegalencephaly (HME). This malformation often is not recognized, despite being the principal cause of neurological manifestations in ENSs. They consist mainly of epilepsy and developmental delay or intellectual disability. The onset of epilepsy in ENS usually is in early infancy, often as infantile spasms. Several syndromic forms have been delineated. I propose the term "Heide's syndrome" for those distinctive cases with the typical triad of hemifacial epidermal nevus, ipsilateral facial lipoma, and hemimegalencephaly. Most ENSs are sporadic. The mechanism is thought to be genetic mosaicism with a lethal autosomal dominant gene. Specific genetic mutations (PTEN, FGFR3, PIK3CA, and AKT1) have been documented in some patients. The large number of contributors for over more than a century and a half to the description of these disorders precludes the use of new author eponyms.

Mosaic RASopathies

"RASopathies" are a group of developmental syndromes with partly overlapping clinical symptoms that are caused by germline mutations of genes within the Ras/MAPK signaling pathway. Mutations affecting this pathway can also occur in a mosaic state, resulting in congenital syndromes often distinct from those generated by the corresponding germline mutations. For syndromes caused by mosaic mutations of the Ras/MAPK signaling pathway, the term "mosaic RASopathies" has been proposed. In the following article, genetic and phenotypic aspects of mosaic RASopathies will be discussed.

Carbon dioxide laser treatment of epidermal nevi: response and long-term follow-up

BACKGROUND AND OBJECTIVES

Epidermal nevi, which are benign skin growths, have been treated using a range of approaches, with varying results. Topical treatments are ineffective and, while surgical excision is a more definitive treatment, it causes scar formation. In recent decades, epidermal nevi have been treated with various types of laser therapy. We describe our experience with the use of carbon dioxide (CO(2)) laser therapy to treat epidermal nevi and inflammatory linear verrucous epidermal nevi (ILVEN).

PATIENTS AND METHODS

Twenty patients (15 with epidermal nevi and 5 with ILVEN) underwent CO(2) laser treatment at our hospital between 2002 and 2010.

RESULTS

Response was good (>50% reduction in lesion size) in 50% of cases and excellent (>75% reduction) in 30%. A greater resistance to treatment was observed in patients with ILVEN (only 40% had a good response). Long-term follow-up (at least 18 months) showed a recurrence rate of 30%. The side effects were hypopigmentation (25% of patients) and scarring (20%).

CONCLUSIONS

We consider CO(2) laser therapy to be the treatment of choice for epidermal nevi as it is well tolerated and has proven to be safe and effective in the long term. While the response in patients with ILVEN was limited, CO(2) laser therapy might be a good option for selected cases or for palliative treatment since no other treatments have yet proven effective in this setting.

Epidermal nevi

Nevi or nests of cells may be made up of a variety of cell types. The cell types that live in the epidermis include epidermal cells or keratinocytes, sebaceous glands, hair follicles, apocrine and eccrine glands, and smooth muscle cells. This article discusses epidermal or keratinocyte nevi, nevus sebaceous, nevus comedonicus, smooth muscle hamartomas, and inflammatory linear verrucous epidermal nevi. Syndromes associated with epidermal nevi are also reviewed.

The group of epidermal nevus syndromes Part II. Less well defined phenotypes

In addition to the well established epidermal nevus syndromes, such as Schimmelpenning, Becker, Proteus, CHILD, or nevus comedonicus syndromes, the group of less well defined phenotypes associated with epidermal nevi presently includes nevus trichilemmocysticus syndrome, didymosis aplasticosebacea, SCALP syndrome (sebaceous nevus, central nervous system malformations, aplasia cutis congenita, limbal dermoid,and pigmented nevus), Gobello syndrome, Bäfverstedt syndrome, NEVADA syndrome (nevus epidermicus verrucosus with angio-dysplasia and aneurysms), and CLOVE syndrome (congenital lipomatous overgrowth, vascular malformations, and epidermal nevus). These syndromes can thus far be regarded as being in limbo. Future clinical and molecular research may show which of these disorders can be added to the list of well defined nosologic entities.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to understand why the list of distinct epidermal nevus syndromes can thus far not be regarded as being complete; why clinicians, when seeing a patient with an epidermal nevus syndrome that is difficult to categorize, should bear in mind the group of less well defined epidermal nevus syndromes; and how practical dermatologists can help recognize rare forms of epidermal nevus syndromes and categorize them appropriately.

Epidermal nevi treated by carbon dioxide laser vaporization: A series of 25 patients

BACKGROUND

Epidermal nevi are benign proliferations of epidermis. Numerous treatment modalities have been tried, but no ideal treatment is yet available.

OBJECTIVE

To report our experience with CO(2) laser vaporization in the treatment of verrucous epidermal nevi, and to identify which factors could have influence in long-term results.

METHODS

A total of 25 patients were treated with the CO(2) laser in the superpulsed mode, focalized at 2 W/cm(2). The patients were between 3 and 41 years old (mean: 17 years). A total of 44% of lesions were <20 cm(2), 40% measured between 20 and 100 cm(2) and 16% were >100 cm(2). The follow-up was 4-79 months (mean: 28 months). In 76% of patients, multiple treatment sessions were required.

RESULTS

Good results were achieved in 92% of patients with soft, flattened nevi and in only 33% patients with keratotic nevi. In addition, 87% of the latter had moderate results and 12.5% had poor results.

CONCLUSION

We conclude that the CO(2) laser in superpulsed mode is an effective and safe treatment for verrucous epidermal nevi and provides fewer recurrences than other laser therapies. We also believe that the most determining factor for the cosmetic result is thickness of the nevus.

Congenital narrow-angle glaucoma and iris nevi in a neonate with epidermal nevus syndrome

Epidermal nevus syndrome (ENS) is a neurocutaneous disorder characterized by epidermal hamartomas and abnormalities of the brain, eye, and other systems. We report the occurrence of congenital angle closure glaucoma in a patient with epidermal nevus syndrome. Intraoperative use of ultrasound biomicroscopy was essential in making the diagnosis.

Epidermal nevus syndrome with azygos anterior cerebral artery

Epidermal nevus syndrome is a neurocutaneous disorder characterized by the association of epidermal nevi with central nervous system or skeletal abnormalities. Central nervous system abnormalities include hemimegalencephaly, hydrocephalus, various migration disorders, intraspinal lipomas, and enlarged spinal roots. Rarely, vascular anomalies cause neurologic signs. We report on a 30-month-old girl with epidermal nevus syndrome who also exhibited vascular malformations of the azygos anterior cerebral artery, a cortical aneurysm, and right internal carotid artery hypoplasia. This rare vascular abnormality was not previously reported in patients with epidermal nevus syndrome.

An epidermal nevus syndrome with cerebral involvement caused by a mosaic FGFR3 mutation

A 5-year-old Mexican girl had a bilateral, systematized epidermal nevus of a non-epidermolytic, non-organoid type covering large parts of her body with the exception of the scalp. Clinically, this nevus was of a soft, velvety type showing affinity to the large body folds. Histopathological examination revealed orthohyperkeratosis and papillomatosis without granular degeneration and without any abnormality of adnexal structures. During infancy she developed seizures, and subsequently a delayed mental development was noted. Computer tomography of the brain revealed cortical and subcortical atrophy, a subdural hygroma in the left frontoparietotemporal region, and hypoplasia of corpus callosum. Molecular analysis of a biopsy specimen obtained from the epidermal nevus revealed a heterozygous R248C hotspot mutation in FGFR3, whereas in normal skin the FGFR3 wild-type allele was exclusively found. The R248C mutation was also present in DNA extracted from blood leukocytes. Because FGFR3 is involved in the development of the central nervous system, the clinical and genetic findings of this case indicate a widespread mosaicism of the FGFR3 mutation. This unusual mosaic phenotype may represent a distinct entity within the group of epidermal nevus syndromes.

Large, papillomatous, pedunculated nevus sebaceus: a new phenotype

We present five cases of an unusual phenotype of nevus sebaceus characterized by large, pink, exophytic nodules. In all cases, no evidence of extracutaneous disease or associated syndromes was observed. We review the clinical presentation of nevus sebaceus, the differential diagnosis of exophytic scalp tumors in the newborn, as well as management of these lesions.

Epidermal nevus syndrome

Epidermal nevus syndrome is a group of congenital neurocutaneous disorders characterized by epidermal nevi in association with cerebral, ocular, skeletal, and sometimes cardiac and renal abnormalities. These nevi have been classified according to their predominant component. We described a child presenting with inflammatory linear verrucous epidermal nevus on the head, which is an uncommon location. He also encountered ocular and central nervous system structural disorders.

Mosaicism of activating FGFR3 mutations in human skin causes epidermal nevi

Epidermal nevi are common congenital skin lesions with an incidence of 1 in 1,000 people; however, their genetic basis remains elusive. Germline mutations of the FGF receptor 3 (FGFR3) cause autosomal dominant skeletal disorders such as achondroplasia and thanatophoric dysplasia, which can be associated with acanthosis nigricans of the skin. Acanthosis nigricans and common epidermal nevi of the nonorganoid, nonepidermolytic type share some clinical and histological features. We used a SNaPshot multiplex assay to screen 39 epidermal nevi of this type of 33 patients for 11 activating FGFR3 point mutations. In addition, exon 19 of FGFR3 was directly sequenced. We identified activating FGFR3 mutations, almost exclusively at codon 248 (R248C), in 11 of 33 (33%) patients with nonorganoid, nonepidermolytic epidermal nevi. In 4 of these cases, samples from adjacent histologically normal skin could be analyzed, and FGFR3 mutations were found to be absent. Our results suggest that a large proportion of epidermal nevi are caused by a mosaicism of activating FGFR3 mutations in the human epidermis, secondary to a postzygotic mutation in early embryonic development. The R248C mutation appears to be a hot spot for FGFR3 mutations in epidermal nevi.

Phacomatosis pigmentokeratotica associated with hemihypertrophy and a rhabdomyosarcoma of the abdominal wall

Phacomatosis pigmentokeratotica (PPK) represents a specific "twin nevus" syndrome in which a speckled lentiginous nevus (SLN) is associated with an organoid nevus with sebaceous differentiation. A boy with a large nevus sebaceus on the left face and upper part of the trunk, a giant segmental SLN extending from the abdomen to the feet bilaterally, and right hemihypertrophy developed an embryonal rhabdomyosarcoma of the right abdominal wall at age 6 months. A variety of musculoskeletal, neurologic, and ocular anomalies have been observed in patients with PPK, reflecting the individual manifestations of both SLN and Schimmelpenning syndromes. This report adds hemihypertrophy to the spectrum of extracutaneous manifestations of PPK and, to our knowledge, represents the first observation of a rhabdomyosarcoma arising in contiguity with an SLN in a patient with PPK. The development of a rhabdomyosarcoma in our patient likely reflects both increased propensity for growth (as evidenced by the hemihypertrophy) and the pluripotent nature of neural-crest derived cells within the field defect that underlies an SLN.

Eccrine angiomatous harmartoma in an infant

Eccrine angiomatous hamartoma is a nevoid proliferation of eccrine glands and small vessels. It usually presents as a solitary, slow growing nodule, manifesting at birth or in childhood, which can be accompanied by hyperhidrosis and pain on palpation. We report an occurrence in an otherwise healthy 3-month-old girl who had multiple, asymptomatic, nodular lesions with a linear arrangement localized to the inguinal fold. We also review the literature on adnexal hamartomas of infancy.

Ojo y piel

Las relaciones entre la patología del ojo y de su revestimiento cutáneo son muy numerosas. Debido a las analogías embriológicas e histológicas, sus principales consecuencias oftalmológicas afectan a la superficie ocular en el sentido más amplio: tegumentos de los párpados, conjuntivas y córnea. La exploración clínica dermatológica sospechará estas alteraciones, que confirmará el oftalmólogo. No obstante, algunos trastornos pueden afectar a todos los demás tejidos oculares. Ya se trate de una localización ocular de algunas enfermedades dermatológicas, como las dermatosis infecciosas, o de auténticos síndromes oculocutáneos, la exploración clínica especializada, y a veces repetida, suele orientar el tratamiento. Las consecuencias sobre la función visual de algunas de estas alteraciones pueden ser graves. La epidermólisis tóxica de Lyell constituye el ejemplo extremo que puede provocar una ceguera corneal bilateral de tratamiento temible. La dermatitis atópica es otro ejemplo de enfermedad más frecuente, pero cuyas complicaciones oculares también pueden amenazar la visión si el tratamiento oftalmodermatológico no es correcto. El ojo y la piel se asocian de nuevo en numerosas enfermedades generales, congénitas, hereditarias o no, o bien adquiridas, cuyos síntomas específicos relacionados con ambas especialidades ayudan a establecer el diagnóstico positivo. Los ejemplos más frecuentes son el lupus, la enfermedad de Behçet, la sarcoidosis y las facomatosis. La superficie ocular conjuntivocorneal comparte con la piel una cierta similitud en cuanto al desarrollo de tumores, pigmentados o no. Por último, merecen describirse las consecuencias oculares de algunos tratamientos dermatológicos. También se hará mención a las situaciones inversas, que son más excepcionales.