Fixation techniques for fine needle aspiration biopsy smears prepared off site

OBJECTIVE: To identify a simple, cost-effective, reliable fixation method f or fine needle aspiration biopsy (FNAB) yielding a specimen suitable for ma il transport. STUDY DESIGN: Smears prepared from 59 FNABs of surgical specimens were fixe d by continuous fixation in 95% ethanol, spray fixation, air drying, ethano l fixation for either 5 minutes or 4 hours followed by spray fixation, or f ixation in 95% ethanol for either 30 minutes or 4 hours followed by air dry ing. Fixation was graded as unsatisfactory, suboptimal, average, good or ex cellent. RESULTS: Of smears continuously fixed in ethanol, 96.6% were graded as exce llent. Of smears fixed in ethanol followed by spray fixation, 93.2% were ex cellent irrespective of fixation time; 64.4% of spray-fixed smears were exc ellent and 27.1% good. Of air dried smears, 93.2% were unsatisfactory or su boptimal; 83.0% of smears fixed in ethanol for 30 minutes and 74.6% of smea rs fixed for 4 hours prior to air drying were unsatisfactory or suboptimal. CONCLUSION: Fixation of smears in 95% ethanol followed by spray fixation pr oduces excellent results, comparable tot hose with continuous fixation in e thanol. Spray fixation is generally good but not consistently excellent. Ai r drying or fixation in ethanol followed by air drying yields unsatisfactor y or suboptimal results in most cases.