MAMMOGRAPHY IMMEDIATELY AFTER STEREOTAXIC BREAST BIOPSY - IS IT NECESSARY

OBJECTIVE. The purpose of this study was to determine whether mammogra phy immediately after stereotaxic core breast biopsy should be perform ed routinely to diagnose hematoma, to confirm the sampling site, and t o establish a new baseline for future mammograms. MATERIALS AND METHOD S. Stereotaxic core biopsies of 113 mammographically indeterminate or suspicious lesions were performed by use of a dedicated stereotaxic ta ble with digital imaging, a 14-gauge needle, and an automated gun. The indication for biopsy was a mass with or without calcifications in 59 cases (52%) and calcifications without a mass in 54 cases (48%). The number of core biopsies per case ranged from one to 16 (mean = six). C raniocaudal and mediolateral oblique mammograms of the sampled breast were obtained immediately after the biopsies and were compared with pr ebiopsy mammograms. In cases with microcalcifications, the mammograms also were compared with specimen radiographs. RESULTS. Mammograms obta ined immediately after the procedure showed changes related to the bio psy in 86 cases (76%). These findings included decreased lesion size i n 11 (10%), air at the biopsy site in 47 (42%), and hematoma, manifest ed as poorly defined increased density at the biopsy site, in 58 (51%) . One hematoma was clinically significant, but the remaining 57 were c linically occult. When core biopsies were performed for calcifications , the postprocedural mammograms showed a decrease in the number of cal cifications in 26 (48%) of 54 cases, but specimen radiographs showed c alcium in 50 (93%) of 54 cases. Four lesions (three masses and one clu ster of microcalcifications) disappeared after biopsy. In three cases, hematomas obscured residual calcifications at the biopsy site. CONCLU SION. Mammography immediately after core biopsy is not necessary for t he diagnosis of procedure-related hematoma and is inferior to specimen radiography for Verifying that calcifications have been sampled. Post procedural mammograms also may be suboptimal for the establishment of a new baseline because of the frequent finding of hematoma.