title: Cystic panfolliculoma.
abstract: Panfolliculoma is a rare follicular neoplasm with differentiation toward both upper (infundibulum and isthmus) and lower (stem, hair matrix, and bulb) segments of a hair follicle. We present an unusual case of cystic panfolliculoma. A 33-year-old Hispanic woman presented with an 8-month history of a 3.0-cm cystic scalp mass. The lesion was excised, and the histologic sections showed a cystic follicular neoplasm that contained corneocytes in basket-woven and laminated array, trichohyalin granules of the inner root sheath, germinative cells, papillae, matrical cells, and "shadow" cells. Cytokeratin 903 and cytokeratin 5/6 immunostains uniformly highlight the tumor cells. Ber-EP4 strongly labels the germinative cells but not the follicular papillae. CD34 labels the surrounding fibrotic stroma and focally the epithelial component.
authors.affiliation: Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9073, USA. mai.hoang@utsouthwestern.edu
authors.forename: Mai P
authors.initials: MP
authors.lastname: Hoang
authors.forename: Brian M
authors.initials: BM
authors.lastname: Levenson
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D004814:Epidermal Cyst / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D005260:Female; D005497:Follicular Cyst / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D018859:Hair Follicle / Q000473:pathology*; D006801:Humans; D007633:Keratins / Q000032:analysis; D018295:Neoplasms, Basal Cell / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D012867:Skin / Q000737:chemistry / Q000473:pathology*; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D000951:Antigens, Neoplasm
chemical_list: D014408:Biomarkers, Tumor; D007633:Keratins; C115012:human epithelial antigen-125; D000951:Antigens, Neoplasm