Errors, limitations, and pitfalls in the diagnosis of central and peripheral nervous system lesions in intraoperative cytology and frozen sections

Abstract

Context:Intraoperative cytology and frozen section play an important role in the diagnosis of neurosurgical specimens. There are limitations in both these procedures but understanding the errors and pitfalls may help in increasing the diagnostic yield.Aims:To find the diagnostic accuracy of intraoperative cytology and frozen section for central and peripheral nervous system (PNS) lesions and analyze the errors, pitfalls, and limitations in these procedures.Settings and Design:Eighty cases were included in this prospective study in a span of 1.5 years.Materials and Methods:The crush preparations and the frozen sections were stained with hematoxylin and eosin method. The diagnosis of crush smears and the frozen sections were compared with the diagnosis in the paraffin section, which was considered as the gold standard.Statistical Analyses Used:Diagnostic accuracy, sensitivity, and specificity.Results:The diagnostic accuracy of crush smears was 91.25% with a sensitivity of 95.5% and specificity of 100%. In the frozen sections, the overall diagnostic accuracy was 95%, sensitivity was 96.8%, and specificity was 100%. The categories of pitfalls noted in this study were categorization of spindle cell lesions, differentiation of oligodendroglioma from astrocytoma in frozen sections, differentiation of coagulative tumor necrosis of glioblastoma multiforme (GBM) from the caseous necrosis of tuberculosis, grading of gliomas in frozen section, and differentiation of the normal granular cells of the cerebellum from the lymphocytes in cytological smears.Conclusions:Crush smear and frozen section are complimentary procedures. When both are used together, the diagnostic yield is substantially increased.

Intraoperative Squash and Touch Preparation Cytology of Brain Lesions Stained with H+E and Diff-Quik™: A 20-Year Retrospective Analysis and Comparative Literature Review

“…The overall diagnostic agreement of SP with histology ranged from 83.7 to 97.6% (mean 91.7%) ( Table 3 ) . Only 6 studies cited sensitivities of 88.8% [4] , 94.3% [26] , 95.5% [25] , 96.0% [11] , 97.9% [13] , and 98.7% [22] , while 6 reported specificities of 75.0% [11] , 81.9% [4] , 87.5% [22] , 95.0% [13] , 95.6% [26] , and 100% [25] . The overall accuracy of SP/TP in our study, including both tumoral and nontumoral brain lesions, was similar to those found in the literature, with a sensitivity and specificity of 97.9 and 100%, respectively.…”

“…TP enables preservation of the cellular architecture and morphological features for subsequent histologic examination [5,11,24,27] , while avoiding the smearing or freezing artifacts of SP or FS [12,24,27] . The low cellular yield with TP can, however, lead to improper tumor grading or misdiagnoses [5,25,27] .…”

Accuracy of Intraoperative Examination in Central Nervous System Lesions: A Study of 133 Cases

“…An accurate diagnosis requires a good correlation between clinical data, imaging tests, and histopathological examination [1, 17, 18]. In our study, the resected specimens for intraoperative examination were not analyzed in the same facility of the surgical center; the imaging modalities are sometimes unavailable in the institution, and thus there is no direct contact with the surgeon.…”

“…Most CNS lesions have a low amount of connective tissue, allowing adequate application of the squash technique, which provides more detailed information on cellular morphology than FS [1, 7, 8]. Meanwhile, FS is more applicable in cases in which performing the squash technique can be difficult, such as lesions that need better evaluation of the architectural aspects and those with firm consistency [6, 7].…”

“…Intraoperative examination can guide the neurosurgeon in selecting the appropriate surgical management [1-3]. Ideally, the examination should be accurate, fast, and allow tissue preservation for further study in paraffin [4-6].…”