Objective: Squash preparation (SP) is a rapid technique for the intraoperative assessment of brain lesions. Only a few studies have employed touch preparation (TP) cytology and Diff-QuikTM (DQ) staining in conjunction with SP. Our study aimed to assess the diagnostic efficacy of SP of brain lesions at our institution, ascertain the additional effect of TP and DQ staining, examine factors affecting the sensitivity and specificity of our methods, and compare our findings with those of previous investigations. Study Design: Our database was searched for all SP/TP of brain lesions examined from January 1996 to December 2016. Results: During this 20-year study period, our search revealed 400 brain lesions diagnosed by SP/TP cytology. There were 338 (84.5%) neoplasms and 62 (15.5%) nonneoplastic lesions. The most common neoplasms were glioblastoma multiforme (24.6%), metastatic cancer (18.3%), meningioma (16.9%), astrocytoma (11.5%), lymphoma (8.3%), oligoastrocytoma (3.3%), and pituitary adenoma (3.3%). There was discordance between the SP/TP and histological diagnoses in 19/338 (5.6%) cases, i.e., 12 misclassifications of tumor subtype and 7 sampling errors. No false-positive cases were detected. Conclusion: Brain SP/TP stained with H+E/DQ demonstrated high sensitivity (97.9%), specificity (100%), and overall diagnostic accuracy (95.3%). The combined methods, in particular, aided in the diagnosis of brain tumors prone to smearing artifacts and certain metastatic malignancies.

Keywords:
Cytology, Intraoperative brain assessment, Brain, Neoplasm, Squash preparation, Touch preparation
1.
Marshall LF, Adams H, Doyle D, Graham DI: The histological accuracy of the smear technique for neurosurgical biopsies. J Neurosurg 1973;39:82-88.
2.
Willems JG, Alva-Willems JM: Accuracy of cytologic diagnosis of central nervous system neoplasms in stereotactic biopsies. Acta Cytol 1984;28:243-249.
3.
Cahill EM, Hidvegi DF: Crush preparations of lesions of the central nervous system. A useful adjunct to the frozen section. Acta Cytol 1985;29:279-285.
4.
Mouriquand C, Benabid AL, Breyton M: Stereotaxic cytology of brain tumors. Review of an eight-year experience. Acta Cytol 1987;31:756-764.
5.
Martinez AJ, Pollack I, Hall WA, Lunsford LD: Touch preparations in the rapid intraoperative diagnosis of central nervous system lesions. A comparison with frozen sections and paraffin-embedded sections. Mod Pathol 1988;1:378-384.
6.
Asha T, Shankar SK, Rao TV, Das S: Role of squash-smear technique for rapid diagnosis of neurosurgical biopsies - a cytomorphological evaluation. Indian J Pathol Microbiol 1989;32:152-160.
7.
Guarda LA: Intraoperative cytologic diagnosis: evaluation of 370 consecutive intraoperative cytologies. Diagn Cytopathol 1990;6:235-242.
8.
Torres LF, Collaco LM: Smear technique for the intraoperative examination of nervous system lesions. Acta Cytol 1993;37:34-39.
9.
Di Stefano D, Scucchi LF, Cosentino L, Bosman C, Vecchione A: Intraoperative diagnosis of nervous system lesions. Acta Cytol 1998;42:346-356.
10.
Shah AB, Muzumdar GA, Chitale AR, Bhagwati SN: Squash preparation and frozen section in intraoperative diagnosis of central nervous system tumors. Acta Cytol 1998;42:1149-1154.
11.
Firlik KS, Martinez AJ, Lunsford LD: Use of cytological preparations for the intraoperative diagnosis of stereotactically obtained brain biopsies: a 19-year experience and survey of neuropathologists. J Neurosurg 1999;91:454-458.
12.
Savargaonkar P, Farmer PM: Utility of intra-operative consultations for the diagnosis of central nervous system lesions. Ann Clin Lab Sci 2001;31:133-139.
13.
Bleggi-Torres LF, de Noronha L, Schneider Gugelmin E, Martins Sebastiao AP, Werner B, Marques Maggio E, Queiroz Telles JE, Martins Collaco L: Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system. Diagn Cytopathol 2001;24:293-295.
14.
Roessler K, Dietrich W, Kitz K: High diagnostic accuracy of cytologic smears of central nervous system tumors. A 15-year experience based on 4,172 patients. Acta Cytol 2002;46:667-674.
15.
Iqbal M, Shah A, Wani MA, Kirmani A, Ramzan A: Cytopathology of the central nervous system. Part I. Utility of crush smear cytology in intraoperative diagnosis of central nervous system lesions. Acta Cytol 2006;50:608-616.
16.
Shukla K, Parikh B, Shukla J, Trivedi P, Shah B: Accuracy of cytologic diagnosis of central nervous system tumours in crush preparation. Indian J Pathol Microbiol 2006;49:483-486.
17.
Goel D, Sundaram C, Paul TR, Uppin SG, Prayaga AK, Panigrahi MK, Purohit AK: Intraoperative cytology (squash smear) in neurosurgical practice - pitfalls in diagnosis experience based on 3057 samples from a single institution. Cytopathology 2007;18:300-308.
18.
Mitra S, Kumar M, Sharma V, Mukhopadhyay D: Squash preparation: a reliable diagnostic tool in the intraoperative diagnosis of central nervous system tumors. J Cytol 2010;27:81-85.
19.
Ghosal N, Hegde AS, Murthy G, Furtado SV: Smear preparation of intracranial lesions: a retrospective study of 306 cases. Diagn Cytopathol 2011;39:582-592.
20.
Sharma S, Deb P: Intraoperative neurocytology of primary central nervous system neoplasia: a simplified and practical diagnostic approach. J Cytol 2011;28:147-158.
21.
Jaiswal S, Vij M, Jaiswal AK, Behari S: Intraoperative squash cytology of central nervous system lesions: a single center study of 326 cases. Diagn Cytopathol 2012;40:104-112.
22.
Krishnani N, Kumari N, Behari S, Rana C, Gupta P: Intraoperative squash cytology: accuracy and impact on immediate surgical management of central nervous system tumours. Cytopathology 2012;23:308-314.
23.
Agrawal M, Chandrakar SK, Lokwani D, Purohit MR: Squash cytology in neurosurgical practice: a useful method in resource-limited setting with lack of a frozen section facility. J Clin Diagn Res 2014;8:FC09-FC012.
24.
Nanarng V, Jacob S, Mahapatra D, Mathew JE: Intraoperative diagnosis of central nervous system lesions: comparison of squash smear, touch imprint, and frozen section. J Cytol 2015;32:153-158.
25.
Chand P, Amit S, Gupta R, Agarwal A: Errors, limitations, and pitfalls in the diagnosis of central and peripheral nervous system lesions in intraoperative cytology and frozen sections. J Cytol 2016;33:93-97.
26.
Kishore S, Bhardwaj A, Kusum A, Thakur B, Kaushik S, Sharma N: Intraoperative squash cytology of central nervous system and spinal cord lesions with histological correlation. Ann Pathol Lab Med 2016;3:61-72.
27.
Sidawy MK, Jannotta FS: Intraoperative cytologic diagnosis of lesions of the central nervous system. Am J Clin Pathol 1997;108:S56-S66.
28.
Tambouret RH, Barkan GA, Kurtyez DFI, Padmanabhan V: FNA cytology: rapid on-site evaluation - how practice varies. CAP Today 2014. http://www.captodayonline.com/fna-cytology-rapid-on-site-evaluation-how-practice-varies/ (accessed March 13, 2017).
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2017
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