ABSTRACT
Seborrheic keratosis (SK) is common benign skin lesion that is almost ubiquitous among older individuals. They occur on the face, neck, trunk (especially the upper back) and extremities, but not on the palms, feet and the mucous membranes. They can be usually diagnozed by clinical examination, but some lesions may mimic melanoma, so biopsy for histopatologic examination may be required, especially when there is a history of recent change. Typical morphological structures can be visible on dermoscopy, which is unfortunately not always helpful. They may occur frequently and earlier at sun-exposed areas (the head and the neck) in individuals residing in tropical climates. Their origin is rather neoplastic (clonal) than hyperplastic. In irritated SKs, apoptosis within areas of squamous differentiation has been found on histopathologic examination (Pesce and Scalora 2000).
