Vacuum-assisted minimally invasive biopsy of soft-tissue tumors.

BACKGROUND Although exact histological characterization of soft-tissue tumors is essential for determining the appropriate therapy, the quality of the histological assessment is often limited by the size of the tissue samples. Incisional biopsy and core needle biopsy have been the most effective techniques for obtaining tissue samples from soft-tissue tumors. This study was performed to investigate whether vacuum-assisted biopsy can serve as a new diagnostic tool for soft-tissue neoplasms. METHODS This retrospective study compared the characterization made with use of vacuum-assisted biopsy of soft-tissue tumors in seventy-five patients between 2004 and 2006 and the characterization made with use of incisional biopsy of tumors in a comparison group of seventy-four patients between 2000 and 2005 with the final characterization made after radical tumor excision. All vacuum-assisted and incisional biopsies were performed by the same experienced surgeons and evaluated by the same experienced pathologists at a single tumor center. The sensitivity, specificity, positive and negative predictive values, and accuracy of the preliminary characterization made with use of each method were calculated on the basis of the final characterization made after excision. RESULTS The vacuum-assisted biopsy procedure was performed successfully in seventy-four (99%) of the seventy-five patients. The accuracy of vacuum-assisted biopsy (96%) was comparable with that of incisional biopsy (99%). Vacuum-assisted biopsy correctly characterized the tumor as benign or malignant in 96% (95% confidence interval [CI], 92% to 100%) of the seventy-five patients compared with 99% (95% CI, 96% to 100%) of the seventy-four patients who underwent incisional biopsy. Vacuum-assisted biopsy correctly characterized the tumor diagnosis in 95% (95% CI, 90% to 100%) of the patients compared with 95% (95% CI, 89% to 100%) for incisional biopsy. Vacuum-assisted biopsy correctly characterized the tumor grade in 89% (95% CI, 82% to 96%) of the patients compared with 88% (95% CI, 80% to 95%) for incisional biopsy. The sensitivity of vacuum-assisted biopsy was 93% (95% CI, 71% to 100%), the specificity and the positive predictive value were both 100%, and the negative predictive value was 91% (95% CI, 85% to 98%). The overall accuracy of vacuum-assisted biopsy was 96% (95% CI, 92% to 100%). CONCLUSIONS Vacuum-assisted biopsy appears to be safe and provides a new tool for the diagnosis of soft-tissue tumors. One advantage of vacuum-assisted biopsy is that it can be performed with use of local anesthesia in an outpatient setting.