title: Cystic trichoblastoma: a report of two cases with an immunohistochemical study.
abstract: We herein report two cases of cystic trichoblastoma with an immunohistochemical study. The histopathological findings in these cases included new information, namely, their being composed of two and three cysts, the cystic components had features of a steatocystoma and a hybrid cyst in one case, and there were projections of an aggregation of trichoblastoma, as well as papillary projections of follicular germinative cells, from the cyst walls. The follicular germinative cells observed in the papillary projections and in the aggregations of trichoblastoma expressed cytokeratin-15 (clone C8/144B) and PHLDA1, markers of follicular stem cells. Cystic trichoblastoma is a unique type of trichoblastoma, which originates from the cyst walls of an infundibular cyst (usually) or steatocystoma/hybrid cyst (rarely). In some cases, a trichoblastic infundibular cyst is considered to be a minor form (or possibly a primitive stage) of cystic trichoblastoma.
authors.affiliation: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Misago
authors.forename: Takuya
authors.initials: T
authors.lastname: Inoue
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Narisawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D005497:Follicular Cyst / Q000473:pathology*; D006201:Hair Diseases / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008297:Male; D012878:Skin Neoplasms / Q000737:chemistry* / Q000473:pathology*; D014157:Transcription Factors / Q000032:analysis; D000951:Antigens, Neoplasm
chemical_list: D014408:Biomarkers, Tumor; D007633:Keratins; D014157:Transcription Factors; C491923:PHLDA1 protein, human; C115012:human epithelial antigen-125; D000951:Antigens, Neoplasm
keywords: PHLDA1; cystic trichoblastoma; infundibular cyst; steatocystoma; trichoblastic infundibular cyst