title: Imprint cytologic features of intracytoplasmic lumina in ependymoma. A report of two cases.
abstract: BACKGROUND
  Intracytoplasmic lumina have been recently recognized as a characteristic histologic feature of ependymoma. However, the cytologic diagnostic usefulness has not been discussed. We encountered two imprint cytology cases of spinal cord ependymomas in which there were intracytoplasmic lumina in the tumor cells.
  
  
  METHODS
  Two women had spinal cord tumors on magnetic resonance imaging. Imprint cytology study was carried out on the resected tumors. The cytologic specimen of the first case, aged 52, showed tumor clusters consisting of elongated epithelioid cells, a few of which also had intracytoplasmic lumina. Histologically, tumor cells formed ependymal rosettes and pseudoperivascular rosettes. There were a few tumor cells with intracytoplasmic lumina. The cytologic specimen of the second patient, aged 37, had scattered and isolated tumor cells with intracytoplasmic lumina resembling signet-ring cells and paired tumor cells forming small, glandlike structures. Histologically, the tumor was composed mainly of signet-ring-like cells containing intracytoplasmic lumina.
  
  
  CONCLUSIONS
  Intracytoplasmic lumina were observed in the imprint cytologic specimens of spinal cord ependymoma. The diagnosis of ependymomas can be made cytologically when intracytoplasmic lumina are found since no other primary neuroepithelial tumors of the central nervous system possess such a characteristic feature.
authors.affiliation: Division of Pathology, Tokyo Medical University Hospital, and Department of Pathology, Tokyo Medical University, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Otani
authors.forename: K
authors.initials: K
authors.lastname: Fujita
authors.forename: A
authors.initials: A
authors.lastname: Yokoyama
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: H
authors.initials: H
authors.lastname: Serizawa
authors.forename: M
authors.initials: M
authors.lastname: Kudo
authors.forename: Y
authors.initials: Y
authors.lastname: Ebihara
mesh_terms: D000328:Adult; D003581:Cytodiagnosis; D004806:Ependymoma / Q000473:pathology / Q000648:ultrastructure*; D006801:Humans; D008875:Middle Aged; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000648:ultrastructure*