Ultrasound Image of the Normal Breast

Abstract

US image of the normal breast is quite variable and depends on the age of the patient and the phase of menstrual cycle in fertile women. Parenchyma normally looks like a layer with slightly decreased echodensity and irregular echostructure. Pregnancy and lactation are associated with significant enlargement of the thickness of glandular tissue, which reaches 25–30 mm. In patients older than 40 years, the number of glandular lobes decreases; adipose tissue starts to prevail over the glandular one. Accessory mammary glands (polymastia), accessory nipples (polythelia), or other variants of ectopic breast tissue are a rather rare anomaly, occurring in 1–6% of cases. Breasts in newborn boys and girls have similar structure. The breasts enlarge by the 7th to 8th day of life in 60% of newborns (crisis genitalis neonatorum). It is a normal physiological transitory condition. Primary breast growth in girls older than 3 years of age requires differential diagnosis with precocious puberty. At later age, there are two periods of increase in the number of breast glandular structures at 4 and 9 years. Normally, distinct breast enlargement is also observed at the age of 11–13 years. The arising pathologies in children form the following groups: breast anomalies (amastia, polythelia, polymastia, aberrant lobes), age-related disturbances (premature or late development), disturbance of symmetric growth of the right and left breasts, hypo- or hypermastia, inflammatory processes and trauma, mastopathy, cysts, ductectasia, and benign tumors (fibroadenoma, hamartoma, etc.). It is necessary to remember about the restrictions for biopsies in children.