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

Pigmented Porokeratosis. A Further Variant?

“…1 Porokeratotic adnexal ostial nevus is another rare entity of porokeratosis involving both acrosyringia and acrotrichia. 5 Porokeratosis can also be divided into localized disorders and disseminated disorders based on their clinical forms. Porokeratosis of Mibelli, linear porokeratosis, and punctate porokeratosis fall under the category of localized porokeratosis, whereas disseminated porokeratosis consists of DSAP, disseminated superficial porokeratosis, and porokeratosis palmaris et plantaris.…”

Pruritic porokeratotic peno-scrotal plaques: Porokeratosis or porokeratotic epidermal reaction pattern? A report of 10 cases

“…Multiple cornoid lamellae have been described arising from adnexal structures in lesions described as porokeratotic adnexal ostial nevus (PAON) which is a unifying term, which includes lesions that have involvement of eccrine and or follicular ostia. [4] Furthermore, the cornoid lamella is no longer considered to be specific for porokeratosis as it has been described in several unrelated conditions and is now considered as an epidermal reaction pattern. [5] We describe 10 young males who presented with pruritic plaques on the peno-scrotal region of several months duration whose clinical appearance was not typical of porokeratosis of Mibelli.…”

Porokeratotic eccrine ostial and dermal duct nevus

“…Earlier, it was hypothetized that it was an epidermal invagination which was widely dilated, keratin plugged acrosyringial duct with dermal duct continuing from the base. [2][3][4] Stoof et al, [3] proposed that the lack of carcinoembryonic antigen (CEA) expression by acrosyringial cells was due to abnormal development of the structure. [2] In recent years, immunohistochemistry with CEA staining the cuticle of the acrosyringium and dermal duct traversing the parakeratotic column but not the inner borders of the epidermal invagination, supports the theory that it represents an abnormally keratinizing epidermal invagination through which an acrosyryngium traverses.…”

“…[1] There are rare case reports of PEODDN associated with conditions like hyperthyroidism and sensory polyneuropathy, breast hypoplasia, Bowen disease, deafness and development delay, seizure disorder, hemiparesis, scoliosis, alopecia, onychodysplasia and squamous cell carcinoma. [2,4,8,9] It is unclear whether these associations are coincidental findings or have causal relationship. Coexistence of linear psoriasis has been reported and was hypothesized that it was due to somatic mutation in a rare gene which is in the spectrum of polygenic predisposition for psoriasis.…”

“…There are reports in literature where the cornoid lamella involves eccrine ducts and hair follicles. [1,4,10] Differential diagnosis includes linear VEN, inflammatory linear VEN, linear porokeratosis, linear psoriasis, punctuate keratoderma and nevus comedonicus. All the above diseases lack the characteristic histological feature of cornoid lamella involving eccrine duct.…”