title: Cytodiagnosis of pilocytic astrocytoma in smear preparations.
abstract: OBJECTIVE
  To assess the cytologic features in smear preparations of 23 pilocytic astrocytomas.
  
  
  METHODS
  Examination of 23 smears.
  
  
  RESULTS
  In all cases, the diagnosis was subsequently confirmed on histologic sections. The smears were moderately cellular, with a variably myxoid background. They showed bipolar "hair" cells with elongated, coarse cytoplasmic processes; bland, oval nuclei; Rosenthal fibers; eosinophilic granular bodies; and hyalinized vessels. Stellate cells and bare tumor nuclei were also present. Nuclear pleomorphism, vascular proliferation, perivascular pseudorosettes, microcalcification and hemosiderin-laden macrophages were infrequent features. Mitoses and necrosis were absent. The differential diagnosis should include diffuse fibrillary astrocytomas of all histologic grades, pleomorphic xanthoastrocytoma, ganglion cell tumor, ependymoma and reactive gliosis.
  
  
  CONCLUSIONS
  Correlation of cytologic features with clinical and radiologic information allows pilocytic astrocytoma to be distinguished from other conditions.
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin.
authors.forename: J G
authors.initials: JG
authors.lastname: Teo
authors.forename: H K
authors.initials: HK
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D002467:Cell Nucleus / Q000648:ultrastructure; D002528:Cerebellar Neoplasms / Q000175:diagnosis / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004806:Ependymoma / Q000175:diagnosis; D005260:Female; D005910:Glioma / Q000175:diagnosis; D005911:Gliosis / Q000175:diagnosis; D006801:Humans; D007223:Infant; D008297:Male; D019574:Optic Nerve Neoplasms / Q000175:diagnosis / Q000473:pathology; D011859:Radiography; D012189:Retrospective Studies; D013048:Specimen Handling / Q000379:methods*; D013125:Spinal Neoplasms / Q000175:diagnosis / Q000473:pathology