We aimed to compare the diagnostic performances of digital mammography (DM), digital breast tomosynthesis (DBT), ultrasound (US), magnetic resonance imaging (MRI), breast specific gamma imaging (BSGI) and/or positron emission tomography/computed tomography (PET/CT) for the detection of invasive lobular carcinoma (ILC).

Index ILCs and multifocal/multicentric (multiple) ILCs were analyzed using various imaging modalities. The final surgical pathology was regarded as the reference standard. The detection rate for index cancers and the diagnostic performance for multiple ILCs per breast were evaluated.

Seventy-eight ILCs in 76 women were enrolled. Twenty-six breasts had multiple ILCs. DM (n=72), DBT (n=15), US (n=77), MRI (n=76), BSGI (n=50), and /or PET/CT (n=74) were performed. For index cancer, the detection rate was 100% for DBT, US, and MRI. For multiple ILCs, the sensitivity was 100% for DBT and MRI (P<0.001). The diagnostic accuracy for multiple ILCs were 73.3% for DBT and 73.0% for PET/CT (P=0.460).

DBT was the most accurate imaging modality for both index and multiple ILCs. PET/CT was also valuable for multiple ILCs, whereas DM and BSGI showed relatively low diagnostic performances. DBT and PET/CT have promising roles in the diagnosis of multiple ILCs.