title: PAX-8 expression in cutaneous ciliated cysts: evidence for Müllerian origin.
abstract: Cutaneous ciliated cysts (CCC) are exquisitely rare, benign cystic lesions demonstrating simple, ciliated epithelial linings reminiscent of fallopian tube epithelium. Most commonly, CCC show a predilection for the lower extremities of young reproductive age women and demonstrate immunohistochemical positivity for estrogen and progesterone receptors, supporting the theory that they are derived from ectopic Müllerian rests. PAX-8 is a paired box gene, important in the development of Müllerian and thyroid organs and has utility in the identification of tumors of Müllerian, renal, and thyroid origin. Prompted by the precedent studies on PAX-8 immunohistochemical expression in tumors of Müllerian origin, this article aimed to explore the utility of this antibody in defining the histogenesis of 2 bona fide cases of CCC, both occurring in young reproductive age women. Herein, 2 prototypic index cases of CCC with strong nuclear positivity for estrogen and progesterone receptors are shown to also have positive nuclear staining for PAX-8, further supporting their likely Müllerian origin. These data support the designation of these lesions as cutaneous Müllerian cysts, distinct from potential ciliated cysts of eccrine origin.
authors.affiliation: *Department of Pathology and Laboratory Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; †Department of Pathology and Laboratory Medicine, Pennsylvania Hospital of the University of Pennsylvania, Philadelphia, PA; and ‡Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, OH.
authors.forename: Amy S
authors.initials: AS
authors.lastname: Joehlin-Price
authors.forename: Jui-Han
authors.initials: JH
authors.lastname: Huang
authors.forename: John S
authors.initials: JS
authors.lastname: Brooks
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Scharschmidt
authors.forename: O Hans
authors.initials: OH
authors.lastname: Iwenofu
mesh_terms: D003560:Cysts / Q000378:metabolism* / Q000473:pathology*; D005187:Fallopian Tubes / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007866:Leg / Q000473:pathology; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000032:analysis / Q000096:biosynthesis*; D012871:Skin Diseases / Q000378:metabolism* / Q000473:pathology*; D055815:Young Adult
chemical_list: D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors