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.

A Case of Unilateral Acanthosis Nigricans / 대한피부과학회지

There are 8 types of acanthosis nigricans(AN) : (1) benign AN, (2) obesity-associated AN, (3) syndromic AN, (4) malignant AN, (5) acral AN, (6) unilateral AN, (7) medication-induced AN, (8) mixed-type AN, when two types are present. Unilateral AN is a rare disorder, probably viewed as a nevoid disorder and sometimes called nevoid acanthosis nigricans. It has a morphologic pattern similar to other forms of AN. It is not associated with syndrome, endocrinopathy, drug or cancer. We describe a case of unilateral AN in a 27 year-old Korean man. He had a broad black hyperpigmented, confluent hyperkeratotic plaque on the left thigh.