title: Squash preparation: A reliable diagnostic tool in the intraoperative diagnosis of central nervous system tumors.
abstract: BACKGROUND
  Intraoperative cytology is an important diagnostic modality improving on the accuracy of the frozen sections. It has shown to play an important role especially in the intraoperative diagnosis of central nervous system tumors.
  
  
  OBJECTIVE
  To study the diagnostic accuracy of squash preparation and frozen section (FS) in the intraoperative diagnosis of central nervous system (CNS) tumors.
  
  
  METHODS
  This prospective study of 114 patients with CNS tumors was conducted over a period of 18 months (September 2004 to February 2006). The cytological preparations were stained by the quick Papanicolaou method. The squash interpretation and FS diagnosis were later compared with the paraffin section diagnosis.
  
  
  RESULTS
  Of the 114 patients, cytological diagnosis was offered in 96 cases. Eighteen nonneoplastic or noncontributory cases were excluded. Using hematoxylin and eosin-stained histopathology sections as the gold standard, the diagnostic accuracy of cytology was 88.5% (85/96) and the accuracy on FS diagnosis was 90.6% (87/96). Among these cases, gliomas formed the largest category of tumors (55.2%). The cytological accuracy in this group was 84.9% (45/53) and the comparative FS figure was 86.8% (46/53). In cases where the smear and the FS diagnosis did not match, the latter opinion was offered.
  
  
  CONCLUSIONS
  Squash preparation is a reliable, rapid and easy method and can be used as a complement to FS in the intraoperative diagnosis of CNS tumors.
authors.affiliation: Department of Pathology, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221 005, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Mitra
authors.forename: Mohan
authors.initials: M
authors.lastname: Kumar
authors.forename: Vivek
authors.initials: V
authors.lastname: Sharma
authors.forename: Debasis
authors.initials: D
authors.lastname: Mukhopadhyay