Neuroendocrine ductal carcinoma in situ of the breast NE-DCIS was recently recognized as a special subtype of DCIS, although the diagnostic criteria for NE-DCIS are yet to be established. DCIS is defined as the immunohistochemical expression of neuroendocrine markers chromogranin A and / or synaptophysin in over 50 of tumor cells. Here, we investigated whether there are signi cant differences in magnetic resonance imaging MRI ndings between NE-DCIS and non-NE-DCIS. The study sample comprised 8 lesions in 7 patients with breast NE-DCIS and 71 lesions in 69 patients with non-NE-DCIS who underwent preoperative MRI and histopathological diagnosis at our hospital from June 2010 to June 2012. The patients were females aged 34-85 years. We examined the lesion type, pattern of time-signal intensity curve TIC on dynamic contrast-enhanced MRI DCE-MRI , presence or absence of bloody duct ectasia delineation, and presence or absence of calci cation on mammography MMG. Mass-type lesions were significantly more common in breast NE-DCIS than in non-NE-DCIS on MRI. On DCE-MRI, the TIC washout pattern was more commonly observed in NE-DCIS than in non-NE-DCIS, and although there was no signi cant difference in the rate of bloody duct ectasia delineation, it was relatively more common in NE-DCIS. MMG revealed a signi cant difference in calci cation between non-NE-DCIS 60.1 and NE-DCIS 0. Mass-type lesions and TIC washout pattern are signi cantly more common in patients with NE-DCIS than in those with non-NE-DCIS on MRI and DCE-MRI.