title: Papillary tumor of the pineal region: Histopathological characterization and review of the literature.
abstract: OBJECTIVE
  The papillary tumor of the pineal region (PTPR) was described as a distinct new entity for the first time in 2003 by our team and has been included in the last 2007 WHO classification of tumors of the Central Nervous System. We describe the histopathological characterization of PTPR and present a review of the literature.
  
  
  METHODS
  The description of the histological and immunological features of PTPR is based on the 2007 WHO classification.
  
  
  RESULTS
  PTPR affects both children and adults, and mostly young adults in the third decade. PTPR is a neuroepithelial tumor occurring in the vicinity of the pineal gland, and characterized by its papillary architecture. The papillae are lined by multi-layered cuboidal to columnar epithelioid tumoral cells arranged in perivascular pseudorosettes. Immunohistochemistry shows strong reactivity for cytokeratins, particularly for cytokeratin 18. On electron microscopy, PTPR reveals ultrastructural features indicative of ependymal differentiation, including abundant microvilli at the apical cell pole. The differential diagnosis includes a variety of other papillary tumors, most notably papillary ependymoma, choroid plexus papilloma, papillary meningioma, and metastatic papillary carcinoma in adults. On the basis of ultrastructural and immunohistochemical features, it has been suggested that a PTPR arises from specialized cytokeratin-positive and nestin-positive ependymal cells that are derived from the subcommissural organ. Although the precise histological grading criteria of PTPR remain to be defined, its biological behavior may correspond to WHO grade II or III.
authors.affiliation: Équipe neuro-oncologie et neuro-inflammation, Inserm U1028, CNRS UMR5292, centre de recherche en neurosciences de Lyon, université Lyon 1, rue Paradin, 69372 Lyon cedex 08, France. Electronic address: michelle.montange@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Fèvre Montange
authors.affiliation: Service de pathologie et de neuropathologie, centre de biologie et pathologie Est, groupement hospitalier Est, hospices civils de Lyon, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: A
authors.initials: A
authors.lastname: Vasiljevic
authors.affiliation: Équipe neuro-oncologie et neuro-inflammation, Inserm U1028, CNRS UMR5292, centre de recherche en neurosciences de Lyon, université Lyon 1, rue Paradin, 69372 Lyon cedex 08, France.
authors.forename: J
authors.initials: J
authors.lastname: Champier
authors.affiliation: Équipe neuro-oncologie et neuro-inflammation, Inserm U1028, CNRS UMR5292, centre de recherche en neurosciences de Lyon, université Lyon 1, rue Paradin, 69372 Lyon cedex 08, France; Service de pathologie et de neuropathologie, centre de biologie et pathologie Est, groupement hospitalier Est, hospices civils de Lyon, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: A
authors.initials: A
authors.lastname: Jouvet
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D004806:Ependymoma / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D010870:Pineal Gland / Q000473:pathology*
keywords: Organe sous-commissural; PTPR; Pineal region; Pineal region papillary tumor; Région pinéale; Subcommissural organ; TPRP; Tumeur papillaire de la région pinéale