title: Histopathologic and ultrastructural features and claudin expression in papillary tumors of the pineal region:  a multicenter analysis.
abstract: Neuroepithelial papillary tumor of the pineal region (PTPR) has been defined as a distinct entity that is increasingly being recognized, with 96 cases now reported. This tumor shares morphologic features with both ependymomas and choroid plexus tumors. PTPR is characterized by an epithelial-like growth pattern in which the vessels are covered by layers of tumor cells forming perivascular pseudorosettes. These tumors exhibit various combinations of papillary and solid architecture, making the differential diagnosis of PTPR difficult to establish. We report the detailed description of the histopathologic features of a large series of PTPRs from 20 different centers and distinguish 2 subgroups of tumors with either a striking papillary growth pattern or a papillary and solid growth pattern. We highlight the findings that PTPRs have unusual vessels with multiple lumina and frequently show detachment of the border of the tumoral cells from the vascular wall. The 2 PTPR subgroups present similar clinical characteristics and immunophenotypes. We confirmed and extended the results of previous ultrastructural studies on the presence of intercellular junctions at the apical part of tumoral cells. The expression of the tight junction proteins claudin-1, claudin-2, and claudin-3 was investigated by immunohistochemistry. Claudin-1 and claudin-3, but not claudin-2, were expressed in PTPRs and in the fetal subcommissural organ, potentially the origin of this tumor. In contrast, all 3 claudins were expressed in choroid plexus papillomas. Claudin expression may help in the diagnosis of PTPRs and can be used in combination with other markers, such as CK18, NCAM, E-cadherin, MAP-2, and Kir 7.1.
authors.affiliation: Centre de Recherche en Neurosciences de Lyon, Equipe Neuro-Oncologie et Neuro-Inflammation, Université de Lyon, Lyon Cedex 08, France. e-mail:michelle.montange@inserm.fr
authors.forename: Michelle
authors.initials: M
authors.lastname: Fèvre Montange
authors.forename: Alexandre
authors.initials: A
authors.lastname: Vasiljevic
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Bergemer Fouquet
authors.forename: Michèle
authors.initials: M
authors.lastname: Bernier
authors.forename: Jacques
authors.initials: J
authors.lastname: Champier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Chrétien
authors.forename: Dominique
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Kemeny
authors.forename: Emmanuèle
authors.initials: E
authors.lastname: Lechapt-Zalcman
authors.forename: Sophie
authors.initials: S
authors.lastname: Michalak
authors.forename: Catherine
authors.initials: C
authors.lastname: Miquel
authors.forename: Karima
authors.initials: K
authors.lastname: Mokthari
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pommepuy
authors.forename: Isabelle
authors.initials: I
authors.lastname: Quintin Roué
authors.forename: Audrey
authors.initials: A
authors.lastname: Rousseau
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Saint-Pierre
authors.forename: Caroline
authors.initials: C
authors.lastname: Salon
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Uro-Coste
authors.forename: Pascale
authors.initials: P
authors.lastname: Varlet
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kratzer
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Ghersi-Egea
authors.forename: Anne
authors.initials: A
authors.lastname: Jouvet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D057167:Claudins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010871:Pinealoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D019108:Tight Junctions / Q000378:metabolism* / Q000648:ultrastructure; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D057167:Claudins