Introduction: Porokeratosis is a rare disorder of keratinization. The presence of amyloid deposits has been observed in inflammatory and tumoral skin diseases.
Objectives: The aim of this study was to determine the frequency of cutaneous amyloidosis in histology samples from various types of porokeratosis diagnosed in our department from 1988 to 2005.
Material and methods: Thirty patients were selected and 34 biopsies of lesions clinically and histologically compatible with porokeratosis were performed. Sections were stained with hematoxylin-eosin and thioflavin T.
Results: Amyloid deposits were observed in 11 biopsies from 9 patients. Most were women in their sixties, with disseminated superficial actinic porokeratosis that had begun at least 5 years earlier. No notable histologic differences were observed between porokeratosis specimens with and without amyloid deposits.
Conclusions: The coexistence of porokeratosis and amyloidosis is a rare occurrence but may be underdiagnosed. In our opinion, the advanced age of the patients and the chronic nature of the lesions would have been predisposing factors for amyloid deposition. The possibility of racial or genetic influences, however, cannot be ruled out.