The role of magnetic resonance imaging in patients with palpable breast abnormalities and negative mammographic and sonographic findings

Objective or purpose of study: The objective of this retrospective study was to determine the frequency of positive findings on breast magnetic resonance imaging (MRI) in patients with palpable breast abnormalities in the setting of negative mammographic and sonographic evaluations. Materials, methods, and procedures: Consecutive patients undergoing breast MRI for palpable abnormalities from January 1, 2005 to December 31, 2015 were identified for this retrospective study. Those with preceding imaging (mammograms or ultrasounds) demonstrating positive findings related to the palpable abnormalities were excluded. The location and the duration of the symptoms, the type and the location of the abnormal MRI findings, and their relationships to the symptoms were recorded. Clinical and imaging follow-up as well as the type and the resultant biopsies were recorded. Patients with less than two years of imaging or clinical follow-up were excluded from the study. Results: 22 004 women presented with palpable abnormalities at one breast imaging center between January 1, 2005 and December 31, 2015. Nine thousand and three hundred and thirty-four patients had negative or benign findings on mammography, ultrasound, or mammography plus ultrasound. Thirty-one patients underwent MRI with the complaint of palpable abnormalities despite negative or benign mammographic and/or sonographic findings. Their age range was between 32 and 74 years, and their mean age was 49 years. Of those who had MRI, twenty-one patients had negative MRI findings. Six patients had negative concordant results for the palpable abnormalities and benign incidental findings. Three patients had benign concordant results for the palpable abnormalities, and one patient had incidental atypia. Twenty-eight patients had negative MRI results in the area of the palpable abnormality, and none of these patients underwent biopsy. Of the 31 cases, four patients (13%) underwent additional examinations (three second-look ultrasounds and one bone scan) after MRI. Five patients (16%) underwent MRI-guided biopsies, two patients (6%) underwent ultrasound-guided biopsies, and one patient (3%) had an excision. All biopsies showed benign results. The Gail risk score was calculated for 22 of them and the mean 5-year risk was 1.64 and the mean lifetime risk was 12.51. Conclusion: Breast MRI to evaluate palpable abnormalities after negative mammography and ultrasound results in a low yield for malignancy. The majority of patients (67.7%) had negative MRI examinations, and there were no malignancies detected. Our findings lead us to believe that there are no data to encourage the use of MRI in patients with palpable abnormalities and negative mammographic and/or ultrasound studies.