Epidermal nevi

Case Report: Sequential postzygotic HRAS mutation and gains of the paternal chromosome 11 carrying the mutated allele in a patient with epidermal nevus and rhabdomyosarcoma: evidence of a multiple-hit mechanism involving HRAS in oncogenic transformation

We report a 7-year-old boy born with epidermal nevi (EN) arranged according to Blaschko's lines involving the face and head, right upper limb, chest, and left lower limb, who developed a left paratesticular embryonal rhabdomyosarcoma at 18 months of age. Parallel sequencing identified a gain-of-function variant (c.37G>C, p.Gly13Arg) of HRAS in both epidermal nevus and tumor but not in leukocytes or buccal mucosal epithelial cells, indicating its postzygotic origin. The variant accounted for 33% and 92% of the total reads in the nevus and tumor DNA specimens, respectively, supporting additional somatic hits in the latter. DNA methylation (DNAm) profiling of the tumor documented a signature consistent with embryonal rhabdomyosarcoma and CNV array analysis inferred from the DNAm arrays and subsequent MLPA analysis demonstrated copy number gains of the entire paternal chromosome 11 carrying the mutated HRAS allele, likely as the result of paternal unidisomy followed by subsequent gain(s) of the paternal chromosome in the tumor. Other structural rearrangements were observed in the tumours, while no additional pathogenic variants affecting genes with role in the RAS-MAPK and PI3K-AKT-MTOR pathways were identified. Our findings provide further evidence of the contribution of "gene dosage" to the multistep process driving cell transformation associated with hyperactive HRAS function.

Linear Nevus Sebaceous Syndrome in a Child With Infantile Spasms and Focal Cortical Dysplasia

Linear nevus sebaceous syndrome (LNSS) is a rare neurocutaneous syndrome with important neurological involvement including brain malformation, focal seizures, and developmental delay. We discuss a case with a unique presentation with localization-related infantile spasms and review the clinical and radiological features of this case. To our knowledge, there are no previously reported cases of LNSS with infantile spasms and cortical dysplasia. Therefore, the presented case will make an important contribution to the available knowledge.

Massive Vulvar Linear Verrucous Epidermal Nevus Presenting at Menarche

BACKGROUND

Epidermal nevi are benign hamartomatous growths of the skin that present at birth and develop in early childhood often linearly along the "lines of Blaschko." Verrucous linear epidermal nevi are the most common epidermal nevi and often are located on the trunk or extremities. There is minimal evidence regarding vulvar involvement and subsequent management of the associated cosmetic deformity in this anatomic location.

CASE

An 11-year-old menarchal girl who underwent full-thickness dermal excision of a 9.6 × 4.5 × 3.2 cm left benign vulvar epidermal nevus (noninflammatory type) with primary reconstruction and closure using a mons rotational skin flap.

SUMMARY AND CONCLUSION

Surgical excision of large vulvar nevi can be achieved with desirable cosmetic outcomes with use of rotational skin flaps and primary closure.

Idiopathic gingival papillokeratosis with crypt formation, a report of 7 cases of a previously undescribed entity: possible unusual oral epithelial nevus?

We report 7 cases of hitherto undescribed keratotic papillary plaques of uncertain etiology involving the gingiva. All 7 cases presented on the anterior maxillary attached gingiva of patients in the second decade. The lesions were asymptomatic and 86% (6 of 7 cases) presented in a bilateral symmetric distribution. Microscopically, the lesions exhibited parakeratosis and papillary acanthosis with parakeratin-filled crypts. No specific etiology such as a factitial habit or a common exogenous agent has been identified. The possibility of a developmental etiology such as an oral epithelial nevus cannot be entirely excluded. We propose the descriptive term idiopathic gingival papillokeratosis with crypt formation (IGPC) for this condition.

First Reported Case of 'Epidermal Nevus Syndrome' with a Triad of Central Nervous System Deformities

Epidermal nevus syndrome (ENS) is a term used to describe the occurrence of an epidermal nevus in association with other extra-cutaneous developmental anomalies, most commonly involving the nervous and musculoskeletal systems. The nevus is classified on the basis of the main component which may be keratinocytic, sebaceous, follicular, apocrine, or eccrine. Most patients who present with ENS is at the time of birth, though some become apparent later in life. This case describes a young female who presented with seizures and cognitive impairment along with a linear epidermal nevus on the midline of her face. The presence of the nevus prompted brain imaging which showed cortical dysplasia, multiple hamartomas in the temporal lobe, thalamus, and periventricular regions along with cerebellar atrophy and Dandy-Walker variant. To our knowledge, this is the first case in which three different types of brain lesions were found in the same patient.

Evaluation of Carbon Dioxide Laser in the Treatment of Epidermal Nevi

BACKGROUND

Epidermal naevi are benign hamartomatous growths of the skin which are generally asymptomatic with a benign course but are cosmetically disagreeable. Topical treatments such as steroids, calcipotriol, 5 fluorouracil, podophyllin, retinoids and cryotherapy are ineffective and surgical excision results in scar formation. Therapy is often challenging.

AIM OF THE STUDY

To study the response of carbon dioxide (CO2) laser in the management of epidermal naevi.

SUBJECTS AND METHODS

We conducted a study of CO2 laser treatment on 15 patients of epidermal naevi, eight with verrucous epidermal naevi and seven with sebaceous naevi. A thorough history and examination was done to rule out any epidermal naevus syndrome. The diagnosis was confirmed by histopathology. The number of treatment sessions varied from 1 to 8.

RESULTS

Response was excellent (>90% reduction in lesion size) in three patients, very good (>75% reduction) in five, good (>50% reduction in lesion size) in five and poor (<50% reduction in lesion size) in two patients. The side effects were hyperpigmentation and scarring. Long-term follow-up over a period of 10 months showed a recurrence rate of 20%.

CONCLUSION

We conclude that CO2 laser treatment might be an effective option with long-term safety, minimal discomfort and rapid recovery.

Mosaic Neurocutaneous Disorders and Their Causes

Neurocutaneous disorders are a heterogeneous group of conditions (mainly) affecting the skin [with pigmentary/vascular abnormalities and/or cutaneous tumours] and the central and peripheral nervous system [with congenital abnormalities and/or tumours]. In a number of such disorders, the skin abnormalities can assume a mosaic patterning (usually arranged in archetypical patterns). Alternating segments of affected and unaffected skin or segmentally arranged patterns of abnormal skin often mirror similar phenomena occurring in extra-cutaneous organs/tissues [eg, eye, bone, heart/vessels, lung, kidney and gut]. In some neurocutaneous syndromes the abnormal mosaic patterning involve mainly the skin and the nervous system configuring a (true) mosaic neurocutaneous disorder; or an ordinary trait of a neurocutaneous disorder is sometimes superimposed by a pronounced linear or otherwise segmental involvement; or, lastly, a neurocutaneous disorder can occur solely in a mosaic pattern. Recently, the molecular genetic and cellular bases of an increasing number of neurocutaneous disorders have been unravelled, shedding light on the interplays between common intra- and extra-neuronal signalling pathways encompassing receptor-protein and protein-to-protein cascades (eg, RAS, MAPK, mTOR, PI3K/AKT and GNAQ pathways), which are often responsible of the mosaic distribution of cutaneous and extra-cutaneous features. In this article we will focus on the well known, and less defined mosaic neurocutaneous phenotypes and their related molecular/genetic bases, including the mosaic neurofibromatoses and their related forms (ie, spinal neurofibromatosis and schwannomatosis); Legius syndrome; segmental arrangements in tuberous sclerosis; Sturge-Weber and Klippel-Trenaunay syndromes; microcephaly/megalencephaly-capillary malformation; blue rubber bleb nevus syndrome; Wyburn-Mason syndrome; mixed vascular nevus syndrome; PHACE syndrome; Incontinentia pigmenti; pigmentary mosaicism of the Ito type; neurocutaneous melanosis; cutis tricolor; speckled lentiginous syndrome; epidermal nevus syndromes; Becker's nevus syndrome; phacomatosis pigmentovascularis and pigmentokeratotica; Proteus syndrome; and encephalocraniocutaneous lipomatosis.

Nevus Sebaceous and Its Association With Neurologic Involvement

Several terms are widely used to define cutaneous lesions affecting the epidermis in association with extracutaneous lesions. Recently, based on the wide spectrum of cutaneous epidermal lesions, the various underlying molecular mechanisms and patterns of associated features have led to improved definitions of these disorders. Nevus sebaceous syndrome has been placed under the umbrella term of epidermal nevus syndrome, in which the nevus sebaceous, a congenital hamartomatous lesion of the epidermis, is associated with anomalies involving the brain, eyes, and bones. Nevus sebaceous and neurologic manifestations were evaluated particularly based on their degree of intellectual delay, seizure type, treatment response, and electroencephalography and neuroradiological findings. A review of the literature in this topic is reported.

Neurocutaneous Manifestations of Genetic Mosaicism

Genetic mosaicism is defined as the presence of two or more genetically distinct cell populations in a single individual. Ever more disorders are found to be manifestations of mosaicism and together constitute a significant proportion of the morbidity confronting pediatric specialists. An emerging category is that of overgrowth syndromes with skin manifestations and neurological or developmental abnormalities, such as the well-known Proteus syndrome. In recent years, we have seen dramatic advances in our understanding of these disorders and we now know the genetic basis of many of them. This has profound consequences for diagnosis, counselling, and even treatment, with therapies targeted to specific pathways becoming available for clinical use. Recognizing such overgrowth syndromes, therefore, is more important than ever. Fortunately, their skin manifestations can provide important diagnostic clues when evaluated in the entire phenotypic context. In this review, I provide an overview of the most frequently seen mosaic neurocutaneous phenotypes and discuss their molecular basis.

A Rare Entity of Giant Epidermal Exophytic Naevus of Hemifacial Region

The term nevi constitute a hamartomatous growth of either skin or mucosa that is generally found at birth or shortly after birth. An epidermal nevus consisting chiefly of sebaceous glands is called as nevus sebaceous. Typically this entity is seen as a solitary bald patch over the scalp at birth. We report a case of exophytic lesion following blaschko's lines at birth. We find this case as peculiar because of the multiplicity of lesions, their pattern of distribution, as well as their atypical morphology.

Nd:YAG Q-switched laser for the treatment of a hemicorporal epidermal nevus: A safe and effective option

Epidermal nevi are benign proliferations of the epidermis for which different treatments have been used with disappointing results due to their recurrences and anesthetic scars. Topical therapies have generally been ineffective and surgical treatment provides more definitive results, but with high risk of scarring. In recent years, multiple laser modalities have been described for the treatment of these lesions. In the literature, there are no reported cases of treatment of these lesions with Neodymium-doped Yttrium aluminum garnet (Nd:YAG) laser. We present the case of a 3-year-old patient with a hemicorporal epidermal nevus treated with Nd:YAG laser at an early stage with good results.

Congenital epidermal nevus

Epidermal nevi are hamartomas that are characterized by hyperplasia of the epidermis and adnexal structures, and may be associated with serious disfiguration. Germline mutations in the FGFR3 gene have found to be the etiology of epidermal nevus. Patients often seek treatment from dermatologic surgeons but even an alert dentist can help to diagnose the lesion from its clinical appearance. Various treatment modalities are available and it is the clinician's choice to choose depending upon the patient's condition.

How to cite this article: Arora B, Khinda VIS, Bajaj N, Brar GS. Congenital Epidermal Nevus. Int J Clin Pediatr Dent 2014;7(1): 43-46.

Congenital and infantile benign skin lesions affecting the hand and upper extremity, part 2: nonvascular neoplasms

This article is part 2 of a 2-part series presented to aid the hand surgeon in becoming familiar with dermatological lesions that may be present on the upper extremity during infancy. The discussion focuses on nonvascular neoplasms grouped into the following categories: epithelial, melanocytic, histiocytic, dermal, fibroblastic, and adipocytic neoplasms. Diagnostic tips are offered, including clinical photographs, to help differentiate between these lesions. In addition, the recommended treatment for each is discussed.

Extensive epidermal naevus in a foal

CASE REPORT

A 2-month-old Standardbred filly was presented for examination and treatment of extensive congenital skin lesions that had a linear distribution on the left front leg extending from the dorsal midline to the metacarpal region. The lesions were surgically excised under general anaesthesia. Surgical excision was curative and there were no signs of recurrence 6 weeks after surgery. The number and distribution of lesions were more extensive than in previously reported cases of congenital papillomas, which have also been described as epidermal growth abnormalities (naevi or hamartomas). Early reports of congenital papillomas suggest in-utero infection with papillomavirus may be responsible, despite a lack of histological features associated with papillomavirus infection. Papillomavirus immunohistochemistry has subsequently proven negative in tested cases.

CONCLUSIONS

The presence at birth, their appearance and the extensive distribution of lesions in this case is similar to verrucous epidermal naevus of humans. A name change from congenital papilloma to epidermal naevus is proposed for this condition in horses.

Isolated unilateral linear epidermal nevus of the upper eyelid

A 75-year-old man presented with a recurrent, unilateral, solitary, linear, corrugated lesion of the right upper eyelid of prolonged duration together with bilateral dermatochalasis. A re-excision with blepharoplasty was performed. Histopathologic analysis of the tissue revealed parallel linear arrays of papillomatosis and acanthosis with overlying basket-weave hyperkeratosis consistent with a linear epidermal nevus. Immunohistochemical studies disclosed normal numbers of intraepidermal melanocytes and Langerhans cells without Merkel cells or an increase in cycling keratinocytes. Although the term "nevus" is mostly used in conjunction with the common nevomelanocytic nevus, in fact nevi of other cutaneous cellular elements can occur on a malformational basis (such as sebaceous, eccrine, apocrine, pilar, and elastic fiber nevi). Ophthalmologists should be aware of epidermal nevi because they are rarely associated with cataracts, malignant cutaneous neoplasms, neurologic abnormalities, and musculoskeletal disorders. For focal lesions like the present one, local excision is appropriate. A select differential diagnosis of histopathologically related conditions is provided.

Linear nevus sebaceous syndrome in a neonate conceived by intracytoplasmic sperm injection

Linear nevus sebaceous syndrome is a multisystem disorder including nevus sebaceous, which is the hallmark of this syndrome, together with central nervous system, ocular and skeletal anomalies. We report a case of extensive skin lesions, CNS and eye anomalies in a full term infant who was conceived by intracytoplasmic sperm injection.

Feline epidermal nevi resembling human inflammatory linear verrucous epidermal nevus

Multiple, pigmented, verrucous, cutaneous lesions in a 2-year-old female cat were pathologically examined. The lesions were linearly arranged on the right side of the body, and had developed along with moderate pruritus since infancy. Histologically, prominent exophytic, papillomatous outgrowths of the epidermis and acanthosis with intense ortho and parakeratotic hyperkeratosis were characteristic of the lesions. Dermal inflammation with mononuclear cells, neutrophils, and eosinophils was also noted. Inclusion bodies, cellular degeneration, and intranuclear viral particles suggesting papillomavirus infection in the keratinocytes were not observed. Papillomavirus antigen and DNA were not detected in the lesions by immunohistochemistry and polymerase chain reaction, respectively. In accordance with these clinical and histopathological features, the cutaneous lesions of the present cat were diagnosed as epidermal nevi, which were consistent with human inflammatory linear verrucous epidermal nevi.

A profound case of linear epidermal nevus in a patient with epidermal nevus syndrome

BACKGROUND

Epidermal nevus syndrome is a multi-system disease with a wide spectrum of clinical presentation. Numerous specialists may be required to address its extra cutaneous manifestations.

MAIN OBSERVATIONS

We report a severe case of epidermal nevus syndrome involving the oral cavity, pharynx, and central nervous system in addition to disfiguring skin lesions.

CONCLUSIONS

Dermatologists are in a unique position to first render the diagnosis of epidermal nevus syndrome for young patients and ensure appropriate follow-up.