Unilateral Acanthosis Nigricans on Non-flexural Area / 대한피부과학회지

Unilateral acanthosis nigricans (AN) is an exceedingly rare disorder, probably viewed as a nevoid disorder and sometimes called nevoid AN, which is characterized by hyperkeratosis, papillomatosis and moderate acanthosis. The lesions of unilateral AN are distributed unilaterally and morphologic features are similar to other forms of AN. It is not associated with a syndrome, endocrinopathy, drugs or cancers. Here we describe a case of unilateral AN in a 16 year-old Korean man who presented with a broad ashy brown hyperpigmented, confluent hyperkeratotic plaque on the right posterior thigh.