Intra‐epidermal and intra‐dermal sebocrine adenoma with cystic degeneration and hemorrhage

Background: The ducts of eccrine glands may give rise to intra‐epidermal, confluent epithelial and intra‐dermal adenomas known as hidroacanthoma simplex, eccrine poroma, and dermal duct tumor, respectively. An apocrine and sebaceous counterpart of the eccrine poroma has been described by several authors as adnexal, poroma‐like adenoma with apocrine and sebaceous differentiation or sebocrine adenoma. Methods: Using clinical history and routine histologic techniques, we describe a new lesion with features similar to sebocrine adenoma but representing the intra‐epidermal and intra‐dermal counterparts with cystic degeneration and hemorrhage. Briefly, an 84‐year‐old female presented with a 6mm dark tan papule on the neck that clinically appeared as an unusual macular seborrheic keratosis with underlying hemorrhage. Results: Histopathological examination showed a benign dermal cystic appendage tumor with pale polygonal cells, occasional non‐keratinizing ducts, sebaceous differentiation and central hemorrhage with fibrin deposits. Serial sections did not reveal any epidermal connection. However, epithelioid cells with large nuclei in an intra‐epidermal pagetoid pattern were focally seen. Conclusion: These findings represent a new cystic, hemorrhagic variant of sebocrine adenoma.