Presentation
Painless swelling of both breasts. No fever.
Patient Data
Bilateral and relatively symmetrical retroareolar heterogeneously hypoechoic areas measuring (22 x 9 mm) on the right, and (22 x 8 mm) on the left containing small cystic areas with increased echogenicity of surrounding subcutaneous soft-tissues.
Case Discussion
Neonatal breast enlargement is a relatively common condition that can be seen in both female/male neonates, due to the influence of the maternal estrogens during fetal life. It can be uni-or bilateral (frequently bilateral), asymptomatic or physiological. It usually is seen in the first week of life and resolves spontaneously within the first 6 months of life.
On ultrasound, the main differential diagnosis of neonatal breast enlargement is neonatal mastitis.