Histologic and Dermoscopic Findings of Clear Cell Acanthosis in Seborrheic Keratosis

Suh, Kee Suck; Han, Sang Hwa; Park, Jong Bin; Kang, Dong Young; Kim, Sang Tae; Jang, Min Soo

Abstract

Clear cell acanthosis is a reaction pattern of the epidermis that can be observed as the chief histopathologic finding in clear cell acanthoma and as a focal change in other epidermal lesions, such as verruca vulgaris and seborrheic keratosis. Dermoscopy is a useful noninvasive tool that permits the visualization of key vascular structures that are usually not visible to the naked eye. A 63-year-old Korean man was presented with 2 year of a well-circumscribed, dome-shaped nodule on the nipple. Our patient represents patterns of both a clear cell acanthoma and a seborrheic keratosis on dermoscopic and histopathologic finding, but, notably, on dermoscopy vascular structures were more irregular linear distribution than classic clear cell acanthoma and different from dotted vessels shown in psoriasis. In this report, we describe a case of clear cell acanthosis in seborrheic keratosis for whom dermoscopy was used as a valuable diagnostic tool.