Examination of the breast, including inspection and palpation, should occur during routine well-child examinations. During puberty, examination of both the male and female breast affords an opportunity to offer reassurance if indicated. When performing female breast examination, the presence of a chaperone is advisable. The clinician should ask the patient to lie supine and to take one arm out of her gown and place it behind her head. The entire breast should be inspected and then palpated using the flat finger pads of the middle three fingers to make dime-sized circles. A systematic approach, such as following the pattern of the spokes of a wheel or horizontal strips, will ensure thorough breast examination. The sexual maturity rating (Tanner stage) of each breast should be noted. It may put young women at ease to teach breast self-examination simultaneously. However, the primary purpose of teaching self-examination is to promote familiarity and acceptance of the breast, not for early detection of breast cancer, which is exceedingly rare in adolescence. The American Cancer Society now considers breast self-examination an optional component of breast cancer screening for women of all ages.

Children of either sex can be born with polythelia (supernumerary nipples) or polymastia (extra breast tissue). These variations can be found anywhere from the axilla to the groin in up to 5% of healthy patients. Because polythelia may be associated with genitourinary abnormalities, a renal ultrasound study may be advisable for infants with this condition if it is accompanied by other congenital anomalies. More than half of both male and female newborns have palpable breast growth, sometimes with bilateral white nipple discharge. This benign condition results from maternal hormonal stimulation and resolves spontaneously, usually by 4 months of age. Although accessory breast tissue is usually asymptomatic, it may become engorged and painful in women during pregnancy or lactation.

Variations of growth and development in girls include breast hypoplasia, asymmetry, and hypertrophy. Amastia (total absence of the breast) is rare and usually unilateral. It is often secondary to chest wall anomalies such as absence of underlying muscle tissue, or Poland syndrome, which is characterized by aplasia of the pectoralis muscles, rib deformities, webbed fingers, and radial nerve palsy. Breast hypoplasia accompanied by signs of androgen excess in a female patient warrants further endocrinologic evaluation. Breast atrophy can be the result of malnutrition or weight loss, as seen with eating disorders or chronic disease.

Breast asymmetry is common, especially during early pubertal breast development. While the breasts are still growing, adolescents can be advised to use bra pads for the smaller breast. Although it frequently corrects by adulthood, visible asymmetry persists in approximately 25% of women, in which case surgical augmentation and reduction mammoplasty are options. Breast hypertrophy, or macromastia, typically begins in adolescence and is associated with obesity. Juvenile, or “virginal,” hypertrophy, with massive diffuse enlargement of one or both breasts during puberty, occurs rarely. Corrective surgery is preferably delayed until after breast development is complete.