Nondiagnostic CT-guided stereotactic biopsies in a series of 407 cases: influence of CT morphology and operator experience

Nondiagnostic biopsies were analyzed in a consecutive series of 407 patients undergoing computerized tomography (CT)-guided stereotactic biopsies. These were categorized as either negative biopsies, when normal tissue or nonspecific pathology was found, or inconclusive, when a definitive diagnosis could not be made although representative tissue was obtained. Nineteen biopsies (4.7%) were negative and 10 (2.4%) were inconclusive, giving an overall nondiagnostic biopsy rate of 7.1% (29 of the 407 cases). Suspected neoplastic masses (390 cases) were classified on the basis of their CT morphology into four groups: Group 1 included purely hypodense nonenhancing masses; Group 2 included isodense nonenhancing masses; Group 3 included ring-enhancing masses; and Group 4 included mixed-density enhancing masses. Although a higher proportion of hypodense nonenhancing masses (six of 56, or 10.7%) yielded a negative result, there was no statistically significant difference in the negative biopsy rates for the differen...