Breast imaging – Mammography interpretation – Understanding the normal mammogram – Physiological variations
Breasts can have physiological changes, and it is important to be able to recognize these when evaluating the normal mammogram. The normal variants commonly seen are the following:
Polymastia (accessory breasts)
An accessory breast is the presence of breast tissue in addition to the normal breasts. The accessory breast may be present anywhere along the embryological mammary line (from the anterior axillary fold to the inguinal region).
A mammography finding of inverted nipple is characterized by nipple inversion in the absence of an underlying retroareolar or parenchymal lesion. The breast parenchyma does not reveal a suspicious mass or microcalcifications. There is no evidence of surgical intervention or trauma. The diagnosis of physiological inverted nipple is then confirmed. It is of three grades:
Grade 1 inverted nipple
Grade 2 inverted nipple
Grade 3 inverted nipple
Asymmetrical breast tissue When an area of one breast has a different volume from the same area of the other breast, it is called asymmetry. Asymmetrical breast tissue is usually normal and caused by hormonal changes during puberty that vary in both breasts. An absence of mass and microcalcifications within the asymmetry confirms that it is a normal variant. An asymmetrical volume of fibroglandular parenchyma with no features of architectural distortion or underlying mass is a common finding on mammography.
Some other normal variants