title: Endoscopic biopsy and third ventriculostomy for the management of pineal region tumors.
abstract: OBJECTIVE
  To assess the histologic accuracy of endoscopic biopsy samples of the pineal region. Pineal region tumors usually present with acute hydrocephalus. Histologic diagnosis is paramount, as it greatly influences treatment. Endoscopic techniques can combine histologic diagnosis with relief of the obstructive hydrocephalus in a single operation. Because pineal region tumors can be heterogeneous, initial biopsy samples may not represent the most aggressive portion of the tumor.
  
  
  METHODS
  This retrospective study reviews our experience of endoscopic third ventriculostomy combined with biopsy of the lesion. The histologic diagnosis as a result of the initial biopsy was compared with the final histologic diagnosis to establish the accuracy of the endoscopic biopsy sample in aiding diagnosis.
  
  
  RESULTS
  Forty-seven patients underwent an endoscopic third ventriculostomy. All but 1 patient underwent a concurrent biopsy of the space-occupying lesion and 39 of 46 patients (85%) had a histologic diagnoses. In the remaining 7 patients (15%), the histology was negative; in 6 cases, the second attempt to obtain a histologic diagnosis was successful (2 repeat endoscopic biopsy samples, 2 resections, 2 stereotactic biopsy samples). In 1 patient a presumed low-grade tectal tumor was followed up with sequential scanning. Twenty-eight patients underwent subsequent operations (24 resections, 4 stereotactic biopsies). In 6 of 28 patients (21%), the histologic report was amended after the second procedure.
  
  
  CONCLUSIONS
  The endoscopic biopsy sample yields an accurate histologic diagnosis for most pineal region tumors, with a positive histologic sample in about 85% of patients. However, the results must be interpreted cautiously, as the heterogeneous nature of these tumors may lead to an approximately 21% error rate in the initial tumor diagnosis.
authors.affiliation: Wessex Neurological Centre, University Hospitals Southampton, Southampton, United Kingdom; Clinical Neurosciences, University of Southampton, Southampton, United Kingdom. Electronic address: a.ahmed@soton.ac.uk.
authors.forename: Aminul I
authors.initials: AI
authors.lastname: Ahmed
authors.affiliation: Neurosciences and Mental Health Research Institute, University of Cardiff, Cardiff, United Kingdom.
authors.forename: Malik J
authors.initials: MJ
authors.lastname: Zaben
authors.affiliation: Wessex Neurological Centre, University Hospitals Southampton, Southampton, United Kingdom.
authors.forename: Nijaguna V
authors.initials: NV
authors.lastname: Mathad
authors.affiliation: Wessex Neurological Centre, University Hospitals Southampton, Southampton, United Kingdom.
authors.forename: Owen C E
authors.initials: OC
authors.lastname: Sparrow
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods*; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007223:Infant; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010871:Pinealoma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D020542:Third Ventricle / Q000601:surgery*; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt; D014696:Ventriculostomy / Q000379:methods*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor
keywords: Endoscopy; Pineal tumors; Sampling error; Ventriculostomy