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Evaluation of rapid staining techniques for cytologic diagnosis of intracranial lesions

Sam N. Long BVSc1, T. James Anderson BVM&S, PhD2, Fenella H. A. Long BVM&S, MVSc, MACVSc3, and Pamela E. J. Johnston BVM&S, PhD4
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  • 1 Department of Small Animal Clinical Studies, University of Glasgow Veterinary School, Bearsden, Glasgow G61 1QH, UK.
  • | 2 Department of Small Animal Clinical Studies, University of Glasgow Veterinary School, Bearsden, Glasgow G61 1QH, UK.
  • | 3 Department of Pathology, University of Glasgow Veterinary School, Bearsden, Glasgow G61 1QH, UK.
  • | 4 Department of Pathology, University of Glasgow Veterinary School, Bearsden, Glasgow G61 1QH, UK.

Abstract

Objective—To evaluate 4 rapid supravital stains and 3 preparation techniques for use in the intraoperative diagnosis of intracranial lesions.

Animals—10 dogs and 1 cat euthanatized for intracranial lesions.

Procedure—Specimens were taken from lesions and slides prepared, using 3 techniques: touch impression, medium-pressure impression, or smear preparation. Preparations were then stained with 4 stains: modified Wright stain, May-Grünwald-Giemsa, toluidine blue, and zynostain and examined in a blinded randomized fashion. Cytologic diagnosis was compared with histopathologic diagnosis and classified on the basis of identification of the pathologic process and specific diagnosis into the following categories: complete correlation, partial correlation, or no correlation.

Results—An overall diagnostic accuracy of 81% (107/132) was achieved on the basis of a combination of partial and complete correlation. Of the stains examined, modified Wright stain appeared to be most accurate, with complete correlation in 17 of 33 (52%) specimens and partial correlation in 12 of 33 (36%) specimens. Of the preparation methods, touch preparation and smear preparation provided the most accurate results, with an overall diagnostic accuracy of 82% (36/44) for both methods. However, smear preparations appeared to be of greater diagnostic value, with fewer nondiagnostic specimens, compared with touch preparations.

Conclusions and Clinical Relevance—Cytologic preparations provide a useful diagnostic tool for the intraoperative diagnosis of intracranial lesions. All stains examined yielded promising results, the most accurate of which appeared to be the modified Wright stain. The smear preparation appeared to be the preparation method of greatest diagnostic value. (Am J Vet Res 2002;63:381–386)

Abstract

Objective—To evaluate 4 rapid supravital stains and 3 preparation techniques for use in the intraoperative diagnosis of intracranial lesions.

Animals—10 dogs and 1 cat euthanatized for intracranial lesions.

Procedure—Specimens were taken from lesions and slides prepared, using 3 techniques: touch impression, medium-pressure impression, or smear preparation. Preparations were then stained with 4 stains: modified Wright stain, May-Grünwald-Giemsa, toluidine blue, and zynostain and examined in a blinded randomized fashion. Cytologic diagnosis was compared with histopathologic diagnosis and classified on the basis of identification of the pathologic process and specific diagnosis into the following categories: complete correlation, partial correlation, or no correlation.

Results—An overall diagnostic accuracy of 81% (107/132) was achieved on the basis of a combination of partial and complete correlation. Of the stains examined, modified Wright stain appeared to be most accurate, with complete correlation in 17 of 33 (52%) specimens and partial correlation in 12 of 33 (36%) specimens. Of the preparation methods, touch preparation and smear preparation provided the most accurate results, with an overall diagnostic accuracy of 82% (36/44) for both methods. However, smear preparations appeared to be of greater diagnostic value, with fewer nondiagnostic specimens, compared with touch preparations.

Conclusions and Clinical Relevance—Cytologic preparations provide a useful diagnostic tool for the intraoperative diagnosis of intracranial lesions. All stains examined yielded promising results, the most accurate of which appeared to be the modified Wright stain. The smear preparation appeared to be the preparation method of greatest diagnostic value. (Am J Vet Res 2002;63:381–386)