MR-IMAGING OF THE BREAST IN PATIENTS WITH OCCULT PRIMARY BREAST-CARCINOMA

PURPOSE: To evaluate the utility of contrast material-enhanced magneti c resonance (MR) imaging of the breast for localization of the site of primary breast carcinoma in patients with isolated ipsilateral axilla ry metastasis, without other focal findings at physical examination or mammography. MATERIALS AND METHODS: Twelve women with biopsy-proved m etastatic adenocarcinoma to axillary lymph nodes and occult primary tu mor underwent MR imaging at 1.5 T with a three-dimensional spoiled gra dient-echo pulse sequence before and after administration of gadopente tate dimeglumine. Enhancing areas were correlated with histopathologic findings at mastectomy (n = 8) or breast-conserving treatment (n = 4) . RESULTS: In nine (75%) of the 12 patients, enhancement was seen on M R images that represented the site of the primary tumor at surgery. Ei ght had focal masses, and one had an area of regional enhancement. Two patients had negative MR findings, and no tumor was found at mastecto my One patient with regional enhancement on MR images had no correspon ding tumor at surgery. CONCLUSION: Breast MR imaging enables identific ation of the site of primary tumor in most patients suspected of havin g occult primary breast cancer, and MR findings can influence surgical treatment.