SQUASH PREPARATION AND FROZEN-SECTION IN INTRAOPERATIVE DIAGNOSIS OF CENTRAL-NERVOUS-SYSTEM TUMORS

OBJECTIVE: To investigate the diagnostic acccuracy of squash preparati on (smears) and frozen section (FS) in the rapid intraoperative diagno sis of central nervous system (CNS) tumors. STUDY DESIGN: One hundred eighty-three CNS tumors were examined over a period of 18 months (Janu ary 1995-June 1996). All these were open biopsies, and the smear inter pretation was compared with FS findings and paraffin section diagnosis . RESULTS: In 183 tumors, squash preparation teas satisfactory in 156 cases (85.2%), and the diagnostic accuracy suns 89.7% (140/156). The a ccuracy of FS diagnosis was 90.4% (141/156). CONCLUSION: The squash sm ear preparation is a fairly accurate and reliable tool in the rapid in traoperative diagnosis of CNS tumors. The accuracy of this technique i s nearly as good Its that of FS (P value = .9877). With the advent of stereotactic biopsies, the pathologist May have to depend entirely upo n cytologic features for a definitive diagnosis.