Syringocystoadenoma papilliferum of the external ear canal: an immunohistochemical study.

Abstract Not available ...Syringocystoadenoma papilliferum (SCAP) is an uncommon benign hamartomatous tumour of the skin characterized by extensive papillary growth of epithelial elements down into the dermis. Fewer than 200 cases have been reported in the literature (1) and approximately one-third were associated with a preexisting nevus sebaceous (2). The lesions have been noted at birth in:/50% of cases, and during infancy and childhood in another 15%. The site of occurrence of SCAP has been the head and neck in:/75% of cases (3). SCAP of the external ear canal is exceedingly rare. In a review of the literature by Muller and Theissig (1), only 11 cases of SCAP of the external ear canal were disclosed. Since that review, another case of congenital syringocystoadenoma of the tragus, concha and lobule extending to the outer ear canal has been described by Jordan et al. (3) in a 2½-week-old infant...