Papular acantholytic dyskeratosis of the anogenital area with positive direct immunofluorescence results

Abstract

Acantholytic dyskeratosis is a distinct histological pattern characterized by hyperkeratotic and parakeratotic epidermis with intraepidermal clefts harbouring acantholytic and dyskeratotic keratinocytes. This histopathological pattern is uncommon in dermatoses of the anogenital region. We report a 30-year-old woman who had numerous smooth whitish papules on the labia majora, perineum and perianal region, which coalesced into plaques in some areas. Microscopically, the lesions showed prominent suprabasal and intraspinous acantholysis with dyskeratotic keratinocytes. Direct immunofluorescence examination revealed intercellular Ig G and C(3) within the epidermis. We were unable to find a similar case of papular acantholytic dyskeratosis of the anogenital area with positive direct immunofluorescence findings reported in the literature, thus in this report, the clinicopathological features of a unique case are presented.

White papules on the anogenital area

“…Typical lesions include multiple, confluent, asymptomatic or pruritic, skin‐coloured to whitish keratotic papules or plaques, most commonly located on the anogenital area (vulva, perineum, perianal area) . There is no related family history reported . PAD should be differentiated from genital warts, lichen planus (LP) and HHD.…”

“…PAD should be differentiated from genital warts, lichen planus (LP) and HHD. PAD exhibits mixed histopathological characteristics of HHD and DD, and typical findings are hyperkeratosis, parakeratosis and focal acantholytic dyskeratosis, with suprabasilar clefts, acantholytic (rounded) and dyskeratotic (corps ronds and grains) keratinocytes, involving the suprabasal layers of the epidermis . There have been 19 cases of PAD reported to date .…”

“…PAD exhibits mixed histopathological characteristics of HHD and DD, and typical findings are hyperkeratosis, parakeratosis and focal acantholytic dyskeratosis, with suprabasilar clefts, acantholytic (rounded) and dyskeratotic (corps ronds and grains) keratinocytes, involving the suprabasal layers of the epidermis . There have been 19 cases of PAD reported to date . Direct immunofluorescence (DIF) was performed in only nine cases, and was negative in all except one case, which showed intraepidermal intercellular IgG and C3 deposition .…”

“…There have been 19 cases of PAD reported to date . Direct immunofluorescence (DIF) was performed in only nine cases, and was negative in all except one case, which showed intraepidermal intercellular IgG and C3 deposition . It is uncertain whether the positive results demonstrated in some patients with acantholytic dermatoses are the result of ‘unmasking’ of sequestered antigens, such as desmogleins, to the immune system during disintegration of desmosomes in the course of acantholysis, or whether they are indicators of a true autoimmune disorder …”

“…DD, an autosomal dominant inherited disorder due to mutations in the ATP2A2 gene (12q23‐24), usually presents during puberty, with hyperkeratotic brown papules on the seborrheic areas of the body and nail changes . Histological findings are hyperkeratosis and focal dyskeratosis, as well as suprabasal acantholysis leading to suprabasal clefts . HHD is an autosomal dominant inherited disorder caused by mutations in the ATP2C1 gene (3q21‐24), presenting before the third to fourth decades of life, with painful erosions and fissures in the flexures.…”