The above described MRI and sonographic findings are consistent with breast abscesses. 

The differential diagnosis of other rim-enhancing breast lesions on MRI:

• invasive ductal carcinoma (IDC): non-otherwise specified (NOS).

• medullary carcinoma

• seroma

• ruptured or inflamed cyst

• granulomatous mastitis

• fibrocystic changes

• invasive or intracystic papillary carcinoma

• phyllodes tumor

• angiosarcoma

Abscess versus infiltrating ductal carcinoma:

• the abscess shows prolonged slow intense enhancement, slow washout (plateau or type II time-intensity curve) with non-enhancing central fluid collection. This is in contrary to the DIC with rapid intense rim-enhancement and delayed centripetal enhancement which is highly specific

• hyperintense on T2WI and STIR. The highly cellular carcinoma with is usually T2 isointense to hypointense

• the abscess is most often near the nipple and is tender, palpable and may have erythema. Associated edema on T2WI. May have associated skin thickening (>2 mm)

• in equivocal cases: US-guided aspiration/drainage. Follow-up after appropriate antibiotic course may be tried