title: Panfollicular carcinoma or trichoblastic carcinoma with panfollicular differentiation?
abstract: Herein, we report two cases of a follicular neoplasm with panfollicular differentiation showing architectural and cytologic findings suggestive of a malignancy. Immunohistochemical analysis of β-catenin expression in the neoplasm showed nuclear and cytoplasmic immunoreactivity, with no reactivity in the transitional and shadow cells, consistent with β-catenin expression of pilomatrical tumors. Staining for BerEp4 was positive at the periphery of both neoplasms, suggesting germinative differentiation of the neoplastic cells, whereas staining for the follicular stem-cell marker PHLDA-1 (TDAG51) showed strong focal expression in the tumor cells of both cases. Given these findings, these neoplasms show features of both panfollicular neoplasms and basal cell carcinoma with panfollicular/matrical differentiation. These are the first cases of this neoplasm reported to date. More reports are needed to assess their malignant potential.
authors: Department of Dermatology, Warren Alpert Medical School of Brown University, Providence, RI, USA.
authors: Flavia
authors: F
authors: Fedeles
authors: Jisun
authors: J
authors: Cha
authors: Michael
authors: M
authors: Chaump
authors: Brian
authors: B
authors: Theroux
authors: David
authors: D
authors: Farrell
authors: Raymond
authors: R
authors: Dufresne
authors: Leslie
authors: L
authors: Robinson-Bostom
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002280:Basal Cell Carcinoma / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D006201:Hair Diseases / Q000378:metabolism / Q000473:pathology*; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: catenin; cutaneous neoplasm; differentiation; hair follicle