Seborrhoeic keratosis

Verruca seborrhoica, verruca seborrhoica senilis, senile wart, seborrhoeic senile wart, seborrhoeic wart, verruca senilis, senile wart, basal cell acanthoma.

Very common, benign tumour.

• More frequent with increasing age
• Women = men
• Eruptive onset in Leser-Trélat syndrome with internal neoplasia in the gastrointestinal tract or haematological disease (both anecdotal), then look for acanthosis nigricans maligna (present in 50% of Leser-Trélat syndrome patients

• Hyperkeratotic type
• Acanthotic type
• Reticular/adenoid type
• Clonal type
• Melanoma

• Unknown
• Probably familial predisposition

• Mostly localised on the trunk, partly pruritic, sharply demarcated, platelet-like, oval brownish-blackish-reddish plaques with a verrucous surface
• Surface microscopically, the horny beads are characteristic

• Clinical picture
• Biopsy
  • In a few cases, the diagnosis cannot be made with certainty clinically

Exophytic, intraepidermal papillomatous proliferation of squamous cells without signs of malignancy. Horn cysts form, which are important dermatoscopically.

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