We performed a prospective study of sixty-two patients who were managed with a closed core needle biopsy in an outpatient clinic for a soft-tissue mass or a bone tumor with soft-tissue extension between August 1, 1992, and June 1, 1994. Eight (13 percent) of the closed core needle biopsies yielded no neoplastic tissue. Two needle biopsies (3 percent), which were of myxomatous masses, did not al...