Cytologic results of fine-needle aspiration biopsies of the central nervous system

Abstract

The cytologic results of 34 fine-needle aspiration (FNA) biopsies of the central nervous system (CNS) are reported. There were 31 intraoperative biopsies performed at the time of craniotomy. All the cases were diagnosed using direct smear preparations stained with Papanicolaou and Diff-Quik (Harleco, NJ) stains. The sensitivity of the procedure was 90.7%, specificity 100%, positive predictive value 100%, and efficiency of the test of 91%. There were no false-positive diagnoses and three false-negative diagnoses. This study attests to the diagnostic accuracy of FNA cytologic examination of the central nervous system. Statistical analysis of the few previous FNA biopsy series of the CNS are presented. Review of the indications, advantages and complications of CNS needle biopsy are discussed. This report supports the role of fine-needle aspiration cytology in the evaluation of CNS lesions. With recent developments in radiologic imaging, especially ultrasound and computed tomography (CT) using stereotactic guidance, specimens can be obtained for cytologic diagnosis using thinner needles. Excellent diagnostic accuracy can be obtained, as pathologists gain greater familiarity with interpreting FNA biopsy material. Other advantages of FNA biopsy of the central nervous system include the low morbidity and mortality of the procedure and the ability to perform the biopsy through a burr hole under local anesthesia and thereby decrease hospitalization time and cost.