Preoperative Magnetic Resonance Imaging FeaturesAssociated with Positive Resection Margins in Patientswith Invasive Lobular Carcinoma

ABSTRACT

Objective@#To investigate preoperative magnetic resonance imaging (MRI) findings associated with resection margin statusin patients with invasive lobular carcinoma (ILC) who underwent breast-conserving surgery. @*Materials and Methods@#One hundred and one patients with ILC who underwent preoperative MRI were included. MRI(tumor size, multifocality, type of enhancing lesion, distribution of non-mass enhancement [NME], and degree of backgroundparenchymal enhancement) and clinicopathological features (age, pathologic tumor size, presence of ductal carcinoma in situ[DCIS] or lobular carcinoma in situ, presence of lymph node metastases, and estrogen receptor/progesterone receptor/humanepidermal growth factor receptor type 2 status) were analyzed. A positive resection margin was defined as the presence ofinvasive cancer or DCIS at the inked surface. Logistic regression analysis was performed to determine pre- and postoperativevariables associated with positive resection margins. @*Results@#Among the 101 patients, 21 (20.8%) showed positive resection margins. In the univariable analysis, NME,multifocality, axillary lymph node metastasis, and pathologic tumor size were associated with positive resection margins.With respect to preoperative MRI findings, multifocality (odds ratio [OR] = 3.977, p = 0.009) and NME (OR = 2.741, p = 0.063)were associated with positive resection margins in the multivariable analysis, although NME showed borderline significance. @*Conclusion@#In patients with ILC, multifocality and the presence of NME on preoperative breast MRI were associated withpositive resection margins.