Invasive Lobular Carcinoma: the Concordance of Pathologic Tumor Size with Magnetic Resonance Imaging

Purpose: The purpose of this study was to determine the adjunct value to mammography and ultrasonography of magnetic resonance imaging (MRI) in determining the presence, extend and multifocality of invasive lobular cancer (ILC). Materials and methods: We retrospectively reviewed 38 ILC lesions that had been detected by mammography, ultrasounography, MRI and that had been diagnosed on the basis of histopathological analysis. The size, presence of multifocality and multicentricity of the tumors were recorded at imaging. The findings were compared with the final pathological size. Results: The mean age of the patients was 63 (range;45–85) years. All of the imaging modalities were performed on each patient. The sensitivity of the detection of ILC was much better with MRI (100%) compared to ultrasounography (95%) and mammography (84%). MRI identified multifocal tumor in seven patients (18.4%) and a contralateral tumor in one patient (2.6%), neither of which was identified with mammography and ultrasounography. MRI overestimated the tumor’s size in 11 tumors and underestimated the tumor’s size in three tumors. Ultrasounography overestimated the tumor size in three tumors and underestimated the tumor size in 18 tumors. Mammography overestimated the tumor’s size in two tumors and underestimated the tumor’s size in 17 tumors. The correlation of the tumor’s size on imaging with final pathology was better for MRI than for mammography and ultrasounography (p = 0.026). Conclusions: MRI has better sensitivity of detection and correlation with ILC tumor size at pathology than mammography and ultrasounography. MRI is shown to be superior to mammography and ultrasounography in detecting multifocal and contralateral tumors.