Korean J Dermatol.  2022 Feb;60(2):125-129.

A Case of Disseminated Superficial Actinic Porokeratosis with Secondary Amyloid Deposits: Dermoscopic Features and Literature Review

• Lee YJ
• Ahn HJ
• Jeong KH
• Shin MK

Abstract

Disseminated superficial actinic porokeratosis (DSAP) is a type of porokeratosis that is characterized by multiple small lesions on the sun-exposed areas of the body. The presence of dermal amyloid deposition associated with disseminated superficial porokeratosis has rarely been reported in the literature. A 69-year-old female presented to our department with multiple pruritic brownish macules. Physical examination revealed scattered 2∼3-mm-sized, brownish-colored, round to annular macules limited to the sun-exposed areas, such as the forearms, lower legs, and upper trunk. Dermoscopy revealed a peripheral rim and central white hub surrounded by brown pigmentation. Skin biopsy of the leg showed not only the typical finding of DSAP, including the cornoid lamella, but also deposits of eosinophilic amorphous materials in the dermis. After Congo red staining, the dermal deposits were confirmed to be amyloid. Herein, we report a rare case of DSAP with dermal amyloid deposition and dermoscopic presentation.

Keyword

Amyloid; Congo red; Dermoscopy; Disseminated superficial actinic porokeratosis; Porokeratosis