Widespread porokeratotic adnexal ostial nevus: Clinical features and proposal of a new name unifying porokeratotic eccrine ostial and dermal duct nevus and porokeratotic eccrine and hair follicle nevus

Mosaic GJB2 mutations in widespread porokeratotic adnexal ostial nevus: Report of two patients

Porokeratotic adnexal ostial nevus (PAON) is a rare adnexal hamartoma characterized by keratotic papules following Blaschko's lines, typically located on the unilateral distal extremities. Cutaneous somatic GJB2 mutations have been linked to the pathogenesis of PAON. However, the genetic mechanism underlying bilateral or extended forms, which are less documented, remains unknown. In this study, we presented two cases of PAON with widespread cutaneous lesions and scalp involvement, and demonstrated the presence of GJB2 mosaic mutations in both patients. We further investigated the mosaic frequency in different tissues to gain insights into the mutation events contributing to the phenotype of widespread PAON. Our findings suggest that early postzygotic mutation causing mosaic GJB2 mutations may contribute to the widespread phenotype of PAON, thereby enriching the disease spectrum and mutation profile of PAON.

Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report

ABSTRACT

Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).

Ichthyosis follicularis syndromes in patients with germline mutations in GJB2

Ichthyosis follicularis (IF) manifests as generalized spiny follicular projections found in syndromic diseases secondary to SREBF1 and MBTPS2 mutations. We sought the genetic cause of IF in two distinct families from a cohort of 180 ichthyosis patients. In Family 1, the proband presented with IF, bilateral sensorineural hearing loss (SNHL) and punctate palmoplantar keratoderma, and compound heterozygous GJB2 mutations were discovered in DNA from peripheral blood lymphocytes: GJB2:c.526A>G and c.35delG. In Family 2, the proband presented with a previously unreported IF phenotype in the context of KID syndrome, and whole-exome sequencing found a de novo heterozygous GJB2:c.148G>A mutation. Histopathology was consistent with porokeratotic eccrine ostial and dermal duct nevus (PEODDN) and IF in Probands 1 and 2, respectively. Our findings add to the clinical and histopathological spectrum of IF and emphasize the association of PEODDN-like entities with GJB2 variants.

Porokeratotic eccrine ostial and dermal duct nevus associated with an 11 megabase 3p deletion

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare eccrine hamartoma; the etiology is incompletely understood. A patient presented with congenital, widespread PEODDN. Clinical assessment, histopathologic, cytogenetic, and molecular genetic investigations on affected cells were pursued. Histopathology confirmed PEODDN, and chromosomal microarray on affected tissues identified a mosaic 3p26.3p25.3 deletion in affected tissues. This 11Mb deletion encompasses 47 OMIM genes. We propose that this and other chromosomal deletions may be implicated in some cases of PEODDN, suggesting locus heterogeneity and underscoring the importance of incorporating cytogenetic and molecular investigations into the multidisciplinary care of individuals with suspected mosaic genetic skin disorders.

Epidermal Nevi: What Is New

This article reviews the clinical findings of epidermal nevi and their associated syndromes and provides an update on their pathogenic genetic changes as well as targeted therapies detailed to date.

A case of porokeratotic adnexal ostial nevus misdiagnosed as wart

Porokeratotic adnexal ostial nevus may be misdiagnosed as wart based on clinical appearance and morphology. An accurate diagnosis through skin biopsy is crucial, as is the inclusion of rare disorders such as porokeratotic adnexal ostial nevus in the differential diagnosis.

Linear porokeratosis with bone abnormalities treated with compounded topical 2% cholesterol/2% lovastatin ointment

We describe a case of linear porokeratosis with associated bone resorption in a 17-year-old female with marked improvement after 2% cholesterol/2% lovastatin ointment application. Porokeratosis is a heterogenous group of keratinization disorders characterized by a cornoid lamella, consisting of focal dyskeratotic cells in the granular layer and columns of parakeratosis. The pathogenesis of porokeratosis is not fully elucidated; however, germline mutations have recently been identified in the mevalonate pathway which can lead to a buildup of metabolites that could play a role in dysmaturation. There has only been one prior report of an affected distal digit with underlying bone resorption in association with linear porokeratosis.

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.

Porokeratotic eccrine and hair follicle nevus: a report of two cases and review of the literature

Porokeratotic eccrine and hair follicle nevus is a very rare non-hereditary disorder of keratinization with eccrine and hair follicle involvement with only 9 cases described in the literature. In 2009 the term porokeratotic anexial ostial nevus was proposed to comprehend porokeratotic eccrine and hair follicle nevus and a related and more common process without follicular involvement: porokeratotic eccrine ostial and dermal duct nevus Recent findings suggest that both entities may be produced by a mutation in GJB2 gene, which is associated to KID syndrome. Herein we report 2 cases of porokeratotic eccrine and hair follicle nevus and review the existing cases in the Spanish and English literature.

Porokeratotic eccrine ostial and dermal duct nevus: a unique case treated with CO2 laser

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare eccrine hamartoma, with treatment generally being unsatisfactory. The unique features of PEODDN presented include bilateral and facial lesions, and extensive body involvement. Management with CO₂ laser was successful, and follow-up will be necessary to monitor for recurrent lesions.

Punctate Porokeratosis Palmaris et Plantaris

Porokeratosis, a keratinization disorder, is probably a group of unrelated conditions with same distinctive histological appearance, featuring cornoid lamellae. A case of punctate porkeratosis in a 24 year old male patient is reported for its rarity.

Porokeratotic eccrine ostial and dermal duct nevus

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare nevoid condition characterized by asymptomatic grouped keratotic papules and plaques with a linear pattern on the extremities, having distinct porokeratotic histopathological features. The lesions usually present at birth or in childhood. We present here a case of late-onset PEODDN in a 23-year-old man who had lesions on the palm, forearm, arm and the chest along the lines of Blaschko, strictly localized to the left side of the body.

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.

Disseminated superficial actinic porokeratosis on the face treated with imiquimod 5% cream

Porokeratoses are a group of hereditary or acquired disorders characterized by annular lesions with an atrophic center and a prominent peripheral ridge. Pathologically, porokeratosis is characterized by the presence of abnormal clones of keratinocytes that form a column of parakeratotic cells, called the cornoid lamella. Fifteen percent of patients of disseminated superficial actinic porokeratosis (DSAP) have facial lesions; other regions like the extensor surface of extremities constitute the majority of reported cases. Exclusively facial lesions are probably less frequent. Rarely, actinic porokeratosis is confined to the nose only. Of reported porokeratosis cases, 7.5% have revealed a malignancy arising within the lesion. We present a case of facial sporadic DSAP that was treated with imiquimod 5% cream in conjunction with a regular sunscreen. Follow-up of this case is important to rule out the possibility of malignant transformation of the lesions.

Porokeratotic eccrine nevus may be caused by somatic connexin26 mutations

Porokeratotic eccrine ostial and dermal duct nevus, or porokeratotic eccrine nevus (PEN), is a hyperkeratotic epidermal nevus. Several cases of widespread involvement have been reported, including one in association with the keratitis–ichthyosis–deafness (KID) syndrome (OMIM #148210), a rare disorder caused by mutations in the GJB2 gene coding for the gap junction protein connexin26 (Cx26). The molecular cause is, as yet, unknown. We have noted that PEN histopathology is shared by KID. The clinical appearance of PEN can resemble that of KID syndrome. Furthermore, a recent report of cutaneous mosaicism for a GJB2 mutation associated with KID describes linear hyperkeratotic skin lesions that might be consistent with PEN. From this, we hypothesized that PEN might be caused by Cx26 mutations associated with KID or similar gap junction disorders. Thus, we analyzed the GJB2 gene in skin samples from two patients referred with generalized PEN. In both, we found GJB2 mutations in the PEN lesions but not in unaffected skin or peripheral blood. One mutation was already known to cause the KID syndrome, and the other had not been previously associated with skin symptoms. We provide extensive functional data to support its pathogenicity. We conclude that PEN may be caused by mosaic GJB2 mutations.

Porokeratotic eccrine ostial and dermal duct nevus

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare variant of porokeratosis with characteristic histological feature of cornoid lamella involving the acrosyringium. We report a classic case of a 20-year-old male, who clinically presented to us with keratotic papules and plaque with pits, few having comedo like plugs, on right palm and sole since 1 year of age. A punch biopsy from palm was diagnostic as well as confirmatory showing cornoid lamella involving an eccrine duct which is the characteristic histopathological feature of PEODDN.

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.

Porokeratotic eccrine duct and hair follicle nevus (PEHFN) associated with keratitis-ichthyosis-deafness (KID) syndrome

Porokeratotic eccrine ostial and dermal duct nevus is a rare hamartomatous malformation, histologically characterized by cornoid lamellae overlying dilated eccrine ostia. The nevus most commonly presents in the form of multiple filiform keratotic spines in a linear arrangement, usually on the distal extremities. Porokeratotic eccrine and hair follicle nevus is thought to be a variant of porokeratotic eccrine ostial and dermal duct nevus that additionally involves hair follicle infundibula. We report a case of widespread Porokeratotic eccrine and hair follicle nevus that developed in a 15-year-old woman with keratitis-ichthyosis-deafness syndrome.