title: Squamous cell carcinoma arising from lesions of porokeratosis palmaris et plantaris disseminata.
abstract: We report a 63-year-old Japanese man with numerous hyperkeratotic papules of porokeratosis palmaris et plantaris disseminata (PPPD) who developed multiple squamous cell carcinomas on the lesional sites of the palms and soles. The hyperkeratotic papules, which showed tightly packed columns of parakeratotic cells in the cornified layer (cornoid lamella), lost granular layer, and dyskeratotic keratinocytes in the epidermis below the cornoid lamella histologically, had been noticed on the palms and soles from the age of 28 and 43, respectively. He has no family history of such hyperkeratotic papules. Treatment with etretinate (10-50 mg/day) was given discontinuously, and the total dose of etretinate amounted to approximately 21 g over 14 years (average: 0.07 mg/kg/day). He noticed erosions on the hyperkeratotic papules on the left sole and palm more than 9 months after cessation of treatment with etretinate. Histological findings showed numerous atypical keratinocytes in the epidermis and upper dermis with mononuclear cell infiltration seen in the upper dermis. The diagnosis of squamous cell carcinoma arising from the lesions of porokeratosis palmaris et plantaris was made. Five erosions with histologically malignant changes were removed 1 cm from the margin of the erosions. These findings suggest that etretinate may have an inhibitory action on malignant changes in PPPD.
authors.affiliation: Department of Dermatology, Ogaki Municipal Hospital, Minaminokawa-cho, 4-86, Ogaki 503-8502, Japan. seimarik@gumail.cc.gifu-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Seishima
authors.forename: T
authors.initials: T
authors.lastname: Izumi
authors.forename: Z
authors.initials: Z
authors.lastname: Oyama
authors.forename: M
authors.initials: M
authors.lastname: Maeda
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000209:etiology* / Q000473:pathology; D005533:Foot Dermatoses / Q000150:complications / Q000473:pathology; D006229:Hand Dermatoses / Q000150:complications / Q000473:pathology; D006801:Humans; D008297:Male; D017499:Porokeratosis / Q000150:complications* / Q000473:pathology; D012867:Skin / Q000473:pathology; D012878:Skin Neoplasms / Q000209:etiology* / Q000473:pathology