title: A Hyalinized Trichilemmoma of the Eyelid in a Teenager.
abstract: A 16-year-old African American male, the youngest patient to date, presented with a well-circumscribed upper eyelid lesion. On excision, the dermal nodule was contiguous with the epidermis, displayed trichohyalin-like bodies in an expanded outer root sheath, and was composed chiefly of small cellular clusters separated by a prominent network of periodic acid Schiff -positive hyaline bands of basement membrane material. The tumor cells were positive for high molecular weight cytokeratins (CK) 5/6, CK14, and CK34βE12 and were negative for CK7, carcinoembryonic antigen and epithelial membrane antigen. Negative S100, glial fibrillary acidic protein, and smooth muscle actin immunoreactions ruled out a myoepithelial lesion. The Ki-67 proliferation index was <10%. The diagnosis was a hyalinized trichilemmoma, contrasting with the more common lobular type. As an isolated lesion, trichilemmoma does not portend Cowden syndrome.
authors.affiliation: *Department of Ophthalmology, Harvard Medical School; †David G. Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye & Ear Infirmary, Boston, Massachusetts, U.S.A.; ‡Department of Ophthalmic Pathology, CBLPath, Inc., Rye Brook, New York, U.S.A.; §Oculoplastic & Orbital Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A.; ‖Department of Dermatology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, U.S.A.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Jakobiec
authors.forename: Anna M
authors.initials: AM
authors.lastname: Stagner
authors.forename: Jodi
authors.initials: J
authors.lastname: Sassoon
authors.forename: Scott
authors.initials: S
authors.lastname: Goldstein
authors.forename: Martin C
authors.initials: MC
authors.lastname: Mihm
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000378:metabolism; D005142:Eyelid Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006223:Hamartoma Syndrome, Multiple / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins