unilateral nevoid acanthosis nigricans on the back: a case report

Unilateral nevoid acanthosis nigricans (unan) is a rare, benign, autosomal dominant form of acanthosis nigricans (an), which is a disorder of keratinization. unlike an, the lesions of unan are distributed unilaterally while the histopathological findings are similar to the common form of an. the first description of unan was given by krishnaram in 1991, and following that report, very few cases have been reported. herein, we present another case of unan localized over the back, in a young adult female.