Naevus comedonicus: a spectrum of body involvement

Giant nevus comedonicus of the entire lower left limb protecting from the associated bullous pemphigoid: A hypothetical role of NEK9 mutation?

We present the case of a 92-year-old woman, with bullous pemphigoid (BP) and a concomitant nevus comedonicus (NC) presenting as an asymptomatic, linear lesion of the entire lower left limb, formed by multiple comedones. Dermoscopy of the NC and histopathology confirmed the clinical and dermoscopic suspect of giant congenital nevus comedonicus. The two entities presented no overlap. In this article, we speculate that a mutation of the NEK9 gene, associated with NC, probably altering the normal follicular differentiation in NC lesions, may hypothetically also influence the expression of BPAG2 in NC. This might possibly influence a protective role of NC lesions towards BP. Undoubtedly, genetic studies would be needed to confirm or reject the proposed hypothesis.

Checking NEKs: Overcoming a Bottleneck in Human Diseases

In previous years, several kinases, such as phosphoinositide 3-kinase (PI3K), mammalian target of rapamycin (mTOR), and extracellular-signal-regulated kinase (ERK), have been linked to important human diseases, although some kinase families remain neglected in terms of research, hiding their relevance to therapeutic approaches. Here, a review regarding the NEK family is presented, shedding light on important information related to NEKs and human diseases. NEKs are a large group of homologous kinases with related functions and structures that participate in several cellular processes such as the cell cycle, cell division, cilia formation, and the DNA damage response. The review of the literature points to the pivotal participation of NEKs in important human diseases, like different types of cancer, diabetes, ciliopathies and central nervous system related and inflammatory-related diseases. The different known regulatory molecular mechanisms specific to each NEK are also presented, relating to their involvement in different diseases. In addition, important information about NEKs remains to be elucidated and is highlighted in this review, showing the need for other studies and research regarding this kinase family. Therefore, the NEK family represents an important group of kinases with potential applications in the therapy of human diseases.

Late-Onset Nevus Comedonicus With Follicular Epidermolytic Hyperkeratosis-Case Report and Review of the Literature

Nevus comedonicus is a rare cutaneous follicular hamartoma, characterized by the clustering of papules with firm, blackened horny buffers. It is usually present at birth or during childhood, although few cases of late-onset disease have been described. We present a case of postmenopausal-onset nevus comedonicus in a 55-year-old white woman without relevant medical history. Skin biopsy showed the typical features of several cyst-dilated follicular structures occupied by keratotic material and the peculiar finding of epidermolytic hyperkeratosis of the follicular epithelial walls. A brief review of the clinical and histological features of other similar cases published in the literature is performed.

Epidermal nevus syndromes: New insights into whorls and swirls

Knowledge of the molecular underpinnings of many epidermal nevi and epidermal nevus syndrome has expanded rapidly in recent years. In this review and update on epidermal nevus syndrome, we will cover recent genetic discoveries involving epidermal nevi, including nevus sebaceus, keratinocytic epidermal nevus, nevus comedonicus, congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome, phakomatosis pigmentokeratotica, Becker's nevus, porokeratotic adnexal ostial nevus, inflammatory linear verrucous epidermal nevi, and cutaneous-skeletal hypophosphatemia syndrome. We will discuss how newly defined mutations relate to the biology reflected in the cutaneous patterns seen in these mosaic disorders and how new molecular data has informed our understanding of these diseases and shaped management decisions.

Multiple vulvar dilated pores in a postmenopausal woman

Winer's dilated pore is an infrequent appendageal tumor characterized by a giant comedone on the face, neck, and upper trunk in adults. We report a 57-year-old woman who developed multiple asymptomatic black papules on both labia majora. Histopathology showed grouped dilated follicles lined by keratinizing squamous epithelium in the superficial dermis. The superficial lining epithelium and interfollicular epidermis were atrophic, while the deep epithelium showed mild proliferation and melanin pigmentation with a few short projections extending into the surrounding dermis. We diagnosed multiple Winer's dilated pores based on late-onset lesions and pathological features. This patient may represent the first case of multiple vulvar Winer's dilated pores. We suggest that electrocautery may be effective for treating this type of superficial entity.

Nevus Comedonicus Syndrome

A case of nevus comedonicus syndrome with atypical cutaneous presentation (widespread involvement without any particular pattern, midline lesions involving lower abdomen and involvement of bilateral pinna), and some unusual skeletal (adduction deformity involving bilateral metatarsal along with medial deviation at the level of tarsometatarsal joint), central nervous system (agenesis of corpus callosum with a interhemispheric cyst), visceral (pancreatic cyst) and neurological manifestations have been illustrated.

Epidermal nevus syndromes

The term epidermal nevus syndrome (ENS) has been used to describe the association of epidermal hamartomas and extracutaneous abnormalities. Although many continue to use the term "ENS," it is now understood that this is not one disease, but rather a heterogeneous group with distinct genetic profiles defined by a common cutaneous phenotype: the presence of epidermal and adnexal hamartomas that are associated with other organ system involvement. One commonality is that epidermal nevi often follow the lines of Blaschko and it appears the more widespread the cutaneous manifestations, the greater the risk for extracutaneous manifestations. The majority of the extracutaneous manifestations involve the brain, eye, and skeletal systems. The CNS involvement is wide ranging and involves both clinical manifestations such as intellectual disability and seizures, as well as structural anomalies. Several subsets of ENS with characteristic features have been delineated including the nevus sebaceus syndrome, Proteus syndrome, CHILD syndrome, Becker's nevus syndrome, nevus comedonicus syndrome, and phakomatosis pigmentokeratotica. Advances in molecular biology have revealed that the manifestations of ENS are due to genomic mosaicism. It is likely that the varied clinical manifestations of ENS are due in great part to the functional effects of specific genetic defects. Optimal management of the patient with ENS involves an interdisciplinary approach given the potential for multisystem involvement. Of note, epidermal nevi have been associated with both benign and malignant neoplasms, and thus ongoing clinical follow-up is required.

Nevus comedonicus in oral-facial-digital syndrome type 1: a new finding or overlapping syndromes?

We report a patient with oral-facial-digital syndrome type 1 (OFDS1) who exhibited features overlapping those of nevus comedonicus syndrome, an unusual presentation that may potentially represent a new variant of OFDS1. OFDS1 and nevus comedonicus syndrome represent two rare syndromes with numerous overlapping features that have yet to be described in relation to one another. The features present in our patient led us to propose the possibility of a new variant of OFDS1 in which nevus comedonicus represents a cutaneous manifestation of the syndrome. Knowledge of this potential relationship is important for identification and management of the syndromes' accompanying manifestations in affected patients and may offer further insight into crossroads of pathogenesis.

Bilateral nevus comedonicus of the eyelids

Nevus comedonicus is a rare developmental abnormality of the infundibulum of the hair follicle. It is usually unilateral and commonly presents at birth or during childhood. A rare case of late-onset, bilateral nevus comedonicus of the eyelids is reported. A 79-year-old man presented with asymptomatic but disfiguring eyelid lesions noted several months earlier. On physical examination, multiple papules resembling comedones were present bilaterally in the eyelids, canthi, temple regions, and bridge of the nose. Microscopically, there were deep invaginations of the follicular canals forming focal tunnels or pseudosinus tracts with poral openings to the surface. These variably cystic structures were lined by keratinizing and nonkeratinizing squamous epithelium, contained concentric lamellae of keratin in their lumens, and some were acutely or chronically inflamed. The diagnosis of a nevus comedonicus was made. The clinical and histopathologic characteristics, pathogenesis, differential diagnosis, and management of nevus comedonicus are briefly discussed.

Dermoscopy on nevus comedonicus: a case report and review of the literature

Nevus comedonicus (NC) is a very rare, benign hamartoma characterised by the occurrence of dilated, comedo-like openings, typically on the face, neck, upper arms, chest or abdomen. In uncertain cases, histopathological examination confirms the diagnosis. The authors suggest dermoscopy as a rapid and useful method of initial diagnosis of nevus comedonicus based upon its distinctive dermoscopic features. The dermoscopy reveals numerous light- and dark-brown, circular or barrel-shaped, homogenous areas with prominent keratin plugs.

Linear morhpea, nevus comedonicus, and lichen striatus in a 5-year-old girl

Linear morphea, lichen striatus, and nevus comedonicus are rare conditions. We describe a five-year-old girl in whom all three of these dermatoses are present.

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.

Role of FGFR2-signaling in the pathogenesis of acne

It is the purpose of this review to extend our understanding of the fibroblast growth factor (FGF) receptor-2b-signaling network in the pathogenesis of acne. A new concept of the role of FGFR2b-signaling in dermal-epithelial interaction for skin appendage formation, pilosebaceous follicle homeostasis, comedogenesis, sebaceous gland proliferation and lipogenesis is presented. The FGFR2-gain-of-function mutations in Apert syndrome and unilateral acneiform nevus are most helpful model diseases pointing the way to androgen-dependent dermalepithelial FGFR2-signaling in acne. Androgen-mediated upregulation of FGFR2b-signaling in acne-prone skin appears to be involved in the pathogenesis of acne vulgaris. In organotypic skin cultures, keratinocyte-derived interleukin-1alpha stimulated fibroblasts to secrete FGF7 which stimulated FGFR2b-mediated keratinocyte proliferation. Postnatal deletion of FGFR2b in mice resulted in severe sebaceous gland atrophy. The importance of FGFR2b in sebaceous gland physiology is further supported by the mode of action of anti-acne agents which have been proposed to attenuate FGFR2b-signaling. Downregulation of FGFR2b-signaling by isotretinoin explains its therapeutic effect in acne. Downregulation of FGFR2b-signaling during the first trimester of pregnancy disturbs branched morphogenesis and explains retinoid embryotoxicity. Insulin-like growth factor-1 (IGF-1), the mediator of growth hormone during puberty, intracts with androgen-dependent FGFR2b-signaling and links androgen- and FGF-mediated signal transduction important in sebaceous gland homeostasis. The search for a follicular defect in the dermalepithelial regulation of growth factor-signaling in acne-prone skin appears to be a most promising approach to clarify the pathogenesis of acne.