title: Histopathological, histogenetic, and immunohistochemical analysis of epidermoid cyst of spleen.
abstract: Splenic cysts are encountered not uncommonly, but large cysts occupying a significant portion of the spleen are extremely rare. We report a case of a young female patient presenting with a large epidermoid cyst involving the majority of the spleen. The patient was involved in a motor vehicle accident during which she sustained multiple rib fractures and traumatic internal organ injuries. She subsequently underwent exploratory laparotomy and splenectomy for grade III splenic lacerations. Incidentally, a 13.3 cm in greatest dimension splenic cyst replacing the majority of the splenic parenchyma was identified. Grossly, the inner lining of cyst was gray-white, smooth, and glistening. Histologically, the thick fibrous cyst wall was composed of stratified squamous epithelium, scattered foci of which were denuded. A panel of properly-controlled immunohistochemical stains was performed and showed the squamous epithelium to be strongly and diffusely immunoreactive with carcinoembryonic antigen (CEA), CA 19-9, and cytokeratin 5/6, focally immunoreactive with HBME-1, and negative for calretinin. The histomorphological features and immunohistochemical staining pattern were consistent with a diagnosis of an epidermoid cyst of the spleen.
authors.affiliation: Department of Pathology, St. John Hospital and Medical Center, Detroit, Michigan 48236, USA. syed.gilani@stjohn.org
authors.forename: S M
authors.initials: SM
authors.lastname: Gilani
authors.forename: R
authors.initials: R
authors.lastname: Tashjian
authors.forename: H
authors.initials: H
authors.lastname: Qu
mesh_terms: D000328:Adult; D018395:CA-19-9 Antigen / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D004814:Epidermal Cyst / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053555:Keratin-5 / Q000378:metabolism; D053553:Keratin-6 / Q000378:metabolism; D013158:Splenic Diseases / Q000378:metabolism* / Q000473:pathology*
chemical_list: D018395:CA-19-9 Antigen; D002272:Carcinoembryonic Antigen; D053555:Keratin-5; D053553:Keratin-6