Background:

Invasive lobular carcinoma (ILC) is more difficult to detect clinically and with conventional imaging than other types of breast cancer [1].  Compared with invasive ductal cancers (IDC), ILC commonly presents as multifocal disease [1].  Compounding the difficulty in imaging detection of ILC is the issue of breast density.  Many studies have confirmed the relationship between high mammographic density (MD) and reduced mammographic sensitivity [2].  MD is itself a risk factor for breast cancer [3].  The National Institute for Health and Care Excellence (NICE) recommend performing breast MRI in patients with ILC who are being considered for breast conserving surgery (BCS) and in cases where breast density precludes accurate mammographic assessment [4].

In our centre MRI is routinely performed for patients with ILC regardless of planned surgical intervention.  Although studies have demonstrated a larger size of the index lesion or additional ipsilateral lesions on MRI a much lower percentage of contralateral disease has been documented [5,6].  Published studies have confirmed that MRI has changed surgical management in a significant proportion of cases [5,7].  Also incomplete surgical excision is common with ILC [8]. 

This work is focused on the usefulness of pre-operative MRI in ILC in correlation with breast density and comparison is made to final histopathological results.