Porokeratosis is a disorder of epidermal keratinization characterized clinically by a distinctive ridge-like border, and histologically by cornoid lamellae. The known clinical variants of porokeratosis are: classic porokeratosis of Mibelli, disseminated superficial (actinic) porokeratosis (DSAP), porokeratosis palmaris et plantaris disseminata, linear porokeratosis and punctate porokeratosis. I...

Porokeratoses are uncommon hereditary or acquired keratinization disorders due to abnormal clones of keratinocytes in the epidermis. Porokeratoses have several clinical features which may occur simultaneously. A rare type is verrucous porokeratosis (VPK). Herein, we present a 47-year-old man with a 4-year history of perianal verrucous lesions and one year history of annular pruritic lesions on ...

Sai Ying Pun Dermatology Clinic, 3/F, Sai Ying Pun Jockey Club Clinic, 134 Queen’s Road West, Hong Kong A young lady presented with a recalcitrant linear scaly plaque on her right leg since infancy. The lesion showed partial response to cryotherapy. Histology reported inflammatory linear verrucous epidermal naevus (ILVEN) and porokeratosis at her age 8 and 19 respectively. The final diagnosis i...

Porokeratosis is a skin disorder clinically characterized by annular plaques with keratotic borders resembling the Great Wall of China and histopathologically by cornoid lamellae. The disease has several clinical variants. Porokeratosis ptychotropica, which has recently become part of these variants, is quite rare and little known. The entity is characterized by verrucous plaques - which may re...

Porokeratosis is an inherited, clonal disorder of epidermal keratinization classically characterized by development of single or multiple annular lesions with raised, sharply marginated, keratotic ridge and central atrophy. This clinical presentation may vary with different types of porokeratosis but histopathologically unified by the consistent finding of ‘cornoid lamella’. Porokeratosis may d...

Cornoid lamellation is a specific disorder of epidermal maturation manifested by a vertical "column" of parakeratosis and is the hallmark of porokeratosis. The cornoid lamella is characterized by a ridgelike parakeratosis. We present 11 patients with solitary lesions of a distinct pattern of cornoid lamellation. The mean age at presentation clinically was 57 years; there were 9 men and 2 women....

Porokeratosis is a genodermatosis characterized by abnormal epidermal keratinization with the histological feature of cornoid lamella. There are many clinical variants, but two or more of these variants rarely occur in a single patient. This variation in clinical presentation may be due to the different phenotypic expression of a common genetic abnormality or may be the consequence of abnormali...

A malignant transformation is known to occur in many nevi such as a sebaceous nevus or a basal cell nevus, but a verrucous epidermal nevus has only rarely been associated with neoplastic changes. Keratoacanthoma, multifocal papillary apocrine adenoma, multiple malignant eccrine poroma, basal cell carcinoma and cutaneous squamous cell carcinoma (CSCC) have all been reported to develop from a ver...