title: Subependymoma revisited: clinicopathological evaluation of 83 cases.
abstract: OBJECTIVE
  Subependymomas are rare ependymal neoplasms. To date, a large clinicopathologic study of these benign neoplasms treated with modern neurosurgical techniques has not been reported.
  
  
  METHODS
  Eighty-three cases of subependymoma were retrieved from the files of the Armed Forces Institute of Pathology. Clinicopathological features were reviewed; chromogenic in situ hybridization analysis for chromosome 22 was performed (n = 8), and patient follow-up was obtained (n = 34). Overall, the patients included 68 males and 15 females, 1.5 to 85 years of age (mean, 51.0 years). Twenty-seven cases were discovered at autopsy and the remaining were surgical specimens (n = 56). Tumors arose in the posterior fossa (n = 43), lateral ventricles (n = 37), spinal cord (2) and only one arose in the temporal horn. Tumors ranged in size from 2.0 mm to 60 mm in greatest dimension (mean, 23.0 mm). Eighteen-percent (15/83) of subependymomas exhibited a mixed histologic pattern; that is, subependymoma together with another glial tumor. The most common mixture (13/15) was subependymoma and ependymoma. Surgical excision was used in all symptomatic patients; 10 patients received radiation. Four patients developed a recurrence due to incomplete excision. All patients were without evidence of disease at the last follow-up: alive (n = 28) or dead (n = 8).
  
  
  CONCLUSIONS
  Age is the only variable found to be significantly associated with survival. Currently, surgical methods result in an excellent long-term clinical outcome. Subependymomas do not appear to be associated with NF2 mutations.
authors.affiliation: Department of Neuropathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA. rushinge@afip.osd.mil
authors.forename: Elisabeth J
authors.initials: EJ
authors.lastname: Rushing
authors.forename: Patrick B
authors.initials: PB
authors.lastname: Cooper
authors.forename: Martha
authors.initials: M
authors.lastname: Quezado
authors.forename: Maria
authors.initials: M
authors.lastname: Begnami
authors.forename: Ana
authors.initials: A
authors.lastname: Crespo
authors.forename: James G
authors.initials: JG
authors.lastname: Smirniotopoulos
authors.forename: James
authors.initials: J
authors.lastname: Ecklund
authors.forename: Cara
authors.initials: C
authors.lastname: Olsen
authors.forename: Mariarita
authors.initials: M
authors.lastname: Santi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002551:Cerebral Ventricle Neoplasms / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004806:Ependymoma / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D018315:Glioma, Subependymal / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000473:pathology; D007223:Infant; D015192:Infratentorial Neoplasms / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D020547:Lateral Ventricles / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018198:Mixed Tumor, Malignant / Q000150:complications / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome