Impact of pre-operative MRI in invasive ductal carcinoma with lobular features on core biopsy

Abstract: Background Invasive breast cancer comprises of a wide spectrum of histological types with different clinical presentation, imaging characteristics and behaviour. Almost 10% of breast cancers with predominantly invasive ductal features have lobular components on core biopsy at primary diagnosis. Although the role of MRI in patients with purely lobular cancers is well established, it is not clear if preoperative MRI is indicated in ductal cancer with lobular features. The aim of this study was to assess the role of pre-operative MRI in patients with invasive ductal cancers with lobular features on core biopsy. Materials and Methods Data regarding patients with lobular features on core biopsy who underwent a pre-operative MRI from January 2015 to December 2017 were retrospectively identified and analysed. Imaging findings, additional investigations and change in treatment plans following the MRI scan were reviewed. Results The study included 120 patients of which 42 patients (35%) required a second look ultrasound. Following a repeat ultrasound scan, 25 breasts and 4 axillae were biopsied. 38% of the breast biopsies and 50% of the axillary biopsies were malignant. Based on MRI findings, treatment plans changed in 22.5% of patients. MRI size was concordant with the histological size in 58.3% cases and MRI was accurate in 90% of patients in detecting multifocal disease requiring mastectomy. Majority of patients with change in the management plans had mixed ductal and lobular cancer on final histology. Conclusion This study has demonstrated that MRI picks up additional malignancies and changes management plan in patients with lobular features on core biopsy and should be considered in the pre-operative work up.