Giant pigmented apocrine hidrocystoma of the scalp.

Hidrocystomas are benign cysts of sweat duct epithelium that can present as single or multiple lesions, with or without pigmentation. The size is typically 1-3mm in diameter. Although hidrocystomas commonly occur in most parts of the head and neck region, occurrence on the scalp is rare. Herein, we present a 29-year-old woman with a giant pigmented apocrine hidrocystoma of the scalp, which, to our knowledge, represents the largest of its kind reported to date.