Invasive ductolobular carcinoma of the breast: spectrum of mammographic, ultrasound and magnetic resonance imaging findings correlated with proportion of the lobular component

PURPOSE: The aim of this study was to describe the imaging features of patients with invasive ductolobular carcinoma of the breast in comparison with the proportion of the lobular component. MATERIALS AND METHODS: We retrospectively reviewed mammographic, sonographic and MRI records of 113 patients with proven ductolobular carcinoma diagnosed between January 2008 and October 2012 according to the BI-RADS ® lexicon, and correlated these to the proportion of the lobular component. RESULTS: At mammography the most common finding (62.9%) for invasive ductolobular carcinoma was an irregular, spiculated and isodense mass. On ultrasound an irregular and hypoechoic mass, with spiculated margins and posterior acoustic shadowing was observed in 46.8% of cases. Isolated mass and mass associated with non-mass like enhancement (NMLE) were the most common findings by MRI (89.4%). Washout pattern in delayed phase was seen in 61.2% and plateau curve was more frequently observed in patients with larger lobular component. Additional malignant findings (multifocality, multicentricity and contralateral disease) did not correlate significantly with the proportion of the lobular component. CONCLUSION: Invasive ductolobular carcinoma mainly presents as an irregular, spiculated mass, isodense on mammography and hypoechoic with posterior acoustic shadowing. On MRI it is usually seen as an isolated mass or as a dominant mass surrounded by smaller masses or NMLE. Washout is the most ordinary kinetic pattern of these tumors. In general, the imaging characteristics did not vary significantly with the proportion of the lobular component.