Reticulated acanthoma with apocrine differentiation.

Reticulated acanthoma with apocrine differentiation (RAAD) represents a rare variant of adnexal neoplasm first described by Ackerman et al. in 1998. It consists of cords and columns of adnexal keratinocytes that form a reticulated pattern. Variable signs of apocrine, sebaceous and follicular differentiation may be present. Since 1998, no further cases of this condition have been published. We report on a lesion excised from the leg of a 46-year-old man, which displayed histopathological features diagnostic of RAAD. Criteria for diagnosis and differential diagnoses are discussed.