Exclusive facial porokeratosis: Histopathologically showing follicular cornoid lamellae

Porokeratoses-A Comprehensive Review on the Genetics and Metabolomics, Imaging Methods and Management of Common Clinical Variants

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid-mevalonate pathway.

Exclusive and Solitary Facial Porokeratosis: Pathogenesis and Literature Reappraisal of a Rare Entity

Porokeratosis is a group of well-known clinically distinct entities, characterised by different clinical aspects, but sharing a single common histological aspect, namely the cornoid lamella. Usually, porokeratosis occurs in the limbs and trunk, while it rarely involves the face, especially as an exclusive, single, and solitary lesion. We report the case of a 52-year-old Caucasian woman, with an 11-month history of a 2-cm slowly growing solitary, keratotic lesion on her left cheekbone. The patient did not present other cutaneous lesions on the face, as well as in other body sites. A cutaneous biopsy showed epidermal hyperplasia with multiple, sharply defined cornoid lamella, associated with an underlying attenuation of the granular layer and scattered dyskeratotic cells in the spinous layer. The superficial dermis underneath showed a mild lymphocytic infiltrate and fibrosis with remodelled collagen bundles. A final diagnosis of solitary facial porokeratosis was made.

Follicular Porokeratosis, a Porokeratosis Variant

Porokeratosis derives from a process of abnormal keratinization, resulting in clinical and histologic variants. Follicular involvement is infrequently described, with previous suggestions that it may represent a distinct condition. We describe a case of typical disseminated superficial actinic porokeratosis with additional clinically prominent folliculocentric keratosis. Histologically, this represented follicular cornoid lamellae. These findings support follicular porokeratosis as an anatomic site variant of porokeratosis, as opposed to a distinct condition. We also want to raise awareness of this variant which clinically should be considered when presented with a discrete papular keratotic eruption.

Punctate follicular porokeratosis: clinical and pathologic features

Porokeratosis is a disorder of keratinization characterized by an abnormal cornoid lamella surrounding an annular, scaly plaque with an atrophic center. A histologic variant of this condition has been proposed, termed follicular porokeratosis, in cases where follicular involvement was contiguous with an annular cornoid lamella. There has been only 1 report of punctate follicular porokeratosis, in which cornoid lamellae originated exclusively from hair follicles with no associated annular plaque. The authors present the second case of punctate follicular porokeratosis, further supporting the contention that this entity is a unique form of porokeratosis rather than a histologic variant. A 56-year-old African American female presented to the dermatology clinic with a 3-month history of keratotic lesions localized on the right posterior shoulder. Examination revealed an area of perifollicular keratotic papules, each surrounded by an erythematous rim. Histopathology revealed a cornoid lamella originating within a hair follicle, with the parakeratotic column protruding through the follicular orifice. The static nature of the condition along with exclusive involvement of hair follicles supports the notion of punctate follicular porokeratosis as a distinct clinical entity. The diagnosis of this condition relies heavily on proper histopathologic sampling revealing punctate follicular cornoid lamellae.

Cornoid lamellation revisited: apropos of porokeratosis with emphasis on unusual clinicopathological variants

Porokeratosis is a family of several disorders characterized histologically by the presence of cornoid lamellae. The presence of cornoid lamellae represents an abnormal form of keratinization, which unifies all types of porokeratosis. A significant variation in lesional morphology can result from peculiarities involving the cornoid lamellae and changes related to epidermal hyperplasia and dermal inflammation. This diversity has led to the recognition of several unusual clinicopathological variants of porokeratosis in recent years. Cornoid lamellation, however, is not pathognomonic of porokeratosis and can be seen in some inflammatory and inherited cutaneous disorders and also as an incidental finding. Some of these conditions can be confused with an atypical presentation of porokeratosis and vice versa. An awareness of the broad morphological spectrum of porokeratosis is crucial to avoid missing the diagnosis when appearances are far from typical. This issue is critical in patient management given the potential premalignant nature of porokeratosis.

Porokeratosis - Head to toe: An unusual presentation

Porokeratosis is a disorder of epidermal proliferation in which many different clinical variants can be distinguished. Herein we report a rare case of porokeratosis involving almost all parts of the body with simultaneous occurrence of various forms of the disease in the same individual (classical porokeratosis of Mibelli, disseminated superficial actinic porokeratosis, hypertrophic porokeratosis, and genital porokeratosis).

Follicular Porokeratosis at alae Nasi; A Case Report and Short Review of Literature

Porokeratosis are disorders of keratinization, characterized histologically by a parakeratotic column, the cornoid lamellae, and clinically by a distinct peripheral ridge. Porokeratosis usually occurs on the trunk or extremities, and facial lesions are rare. Follicular involvement, identified by follicular localization of cornoid lamellae, is uncommon and described only in association with disseminated superficial actinic porokeratosis (DSAP) and porokeratosis Mibelli (PM). A 34-Year- old woman is presented with asymptomatic 1 cm plaque lesion with hyperkeratotic ridge and depressed center on her nose since three years. Histopathological examination of a biopsy revealed cornoid lamellae confined exclusively to the follicle.

Follicular disorders of the face

Follicular disorders are possibly a commonly seen, though rarely reported, group of disorders, which are localized around follicles and appendages and clinically present as small papules. Classically, clinicopathological follicular plugging is seen in the "true" follicular disorders, which are appropriately referred to as follicular keratosis. Another subtype is folliculitis (infectious or noninfectious) and the follicular mimickers that clinically resemble "true" follicular disorders without the follicular keratoses. Acne vulgaris has an amalgamation of all the above lesion types. Our review is aimed at describing all the follicular disorders and gives an algorithm for diagnosing the common follicular disorders.