BACKGROUND: More than 90% of neurosurgical per-operative cytological results have a good correlation with histopathology. However, its real necessity is sometimes questioned. OBJECTIVE: Evaluate the necessity of per-operatory exam regarding immediate neurosurgical procedure. MATERIAL AND METHODS: We reviewed 130 per-operative exams requested out of 293 surgical procedures for expansive extra or intra-axial CNS lesions, 46 stereotactic biopsies and 84 open surgeries, performed from 1998 to 2001. Smears were prepared, the results compared to the histopathological data and then the neurosurgeons were argued about its necessity and influence upon the surgical procedure, case by case. RESULTS: The per-operative exam was requested in 44.4% of the total number of surgeries performed, 84% of which were relevant for the procedure, or, in biopsies, to evaluate sample representativeness, corresponding to 37.2% of the total number of surgeries performed in that period. Once stereotactic biopsies were excluded, considering that in such cases the per-operative exam is unquestionable, the previous value dropped to 75%; the per-operative smear was considered unnecessary mainly in extra-axial lesions, usually required because of neurosurgeons' curiosity. CONCLUSION: Despite its well-known accuracy, per-operative exams performed without a real necessity for the surgical procedure could overcharge pathologists unnecessarily. Our results have shown that the exam was useful in the great majority of cases, even excluding stereotactic biopsies; they also help us evaluate the demand for per-operative exams, sometimes excessive, although important for practicing and teaching purposes.
Neurosurgery; Smear; Per-operative diagnosis
