Invasive Lobular Carcinoma: Detection with Mammography, Sonography, MRI, and Breast-Specific Gamma Imaging

OBJECTIVE. The objective of our study was to compare the sensitivity of mammography, sonography, MRI, and breast-specific gamma imaging (BSGI) in the detection of invasive lobular carcinoma. MATERIALS AND METHODS. This is a retrospective multicenter study of women with biopsy-proven invasive lobular carcinoma. All patients had undergone mammography and BSGI, and the imaging findings were classified as positive or negative for invasive lobular carcinoma by experienced breast imagers. The results of MRI and sonography, if either was performed, were included. Final surgical pathology results were used as the reference standard and the lesion sensitivities of BSGI, mammography, sonography, and MRI were then statistically compared using CIs. RESULTS. Twenty-six women ranging in age from 46 to 82 years (mean age, 62.8 years) with a total of 28 biopsy-proven invasive lobular carcinomas were included in the study group. Mammograms were negative in six of 28 (21%), yielding a sensitivity of 79%. In the 25 patients who underwent sonography, 17 had focal hypoechoic areas, yielding a sensitivity of 68%. In the 12 patients who underwent MRI, the sensitivity was 83%. BSGI had a sensitivity of 93%. There was no statistically significant difference in the sensitivity of BSGI, MRI, sonography, or mammography, although there was a nonsignificant trend toward improved detection with BSGI. CONCLUSION. BSGI has the highest sensitivity for the detection of invasive lobular carcinoma with a sensitivity of 93%, whereas mammography, sonography, and MRI showed sensitivities of 79%, 68%, and 83%, respectively. BSGI is an effective technique that should be used to evaluate patients with suspected cancer and has a promising role in the diagnosis of invasive lobular carcinoma.