Percutaneous ultrasound-guided needle biopsy of hepatic mass lesions using a cytohistologic approach. Comparison of two needle types.

This study compared the ability to diagnose and accurately classify hepatic mass lesions by ultrasound-guided biopsy using two different needle types: a 20 gauge needle that yielded primarily cytologic material and an 18 gauge automated core biopsy needle. Slides prepared from each of the needle types were separately evaluated in a blinded fashion. The 20 gauge needle had a sensitivity of 90%, a specificity of 90%, and enabled exact tumor classification in 70% of cases. The 18 gauge core biopsy had a sensitivity of 85%, a specificity of 100%, and allowed exact tumor typing in 82% of cases. The sensitivity and specificity of both needle types combined was 98% and 100%, respectively, and all malignancies were correctly typed. A combined cytohistologic approach provides a highly accurate means of diagnosing and typing hepatic tumors and provides a suitable sample for confirmatory stains. Accurate tumor typing may affect therapeutic decisions.