Some newborns may have minor breast budding due to transplacental passage of maternal hormones in utero. Similarly, newborn breasts may produce witches’ milk, which is a bilateral white nipple discharge, also a result of maternal hormone stimulation. Both effects are transient and diminish over several weeks to months.
At puberty, under the influence of ovarian hormones, the breast bud grows rapidly. The epithelial sprouts of the mammary gland branch further and become separated by increasing deposition of fat. Such breast development, termed thelarche, begins in most girls between the ages of 8 and 13 years. Thelarche prior to age 8 or lack of breast development by age 13 is considered abnormal and investigated.
Breast examination begins in the newborn period and extends through the prepubertal and adolescent years, as abnormalities can develop in any age group. Assessment includes inspection for accessory nipples, infection, lipoma, fibroadenoma, and premature thelarche.
Accessory nipples, also termed polythelia, are common and noted in 1 percent of patients. Most frequently, a small areola and nipple are found along the embryonic milk line, which extends from the axilla to the groin bilaterally. Accessory nipples are usually asymptomatic, and excision is not required. Rarely, however, they may contain glandular tissue that can lead to pain, nipple discharge, or development of fibroadenomas.
Thelarche may begin before age 8 in some girls and if early, is most commonly seen in girls younger than 2 years. This early breast maturation is termed premature thelarche. It differs from precocious puberty in that it is self-limited and develops in isolation, without other signs of pubertal development. Premature thelarche is suspected when minimal breast tissue growth or nipple maturation is noted during surveillance, but the patient’s height, which is measured to exclude a growth spurt, falls within established percentile curves. Monitoring body growth and breast changes alone may suffice, but in those with increased height or weight or with other pubertal changes, additional testing for precocious puberty is warranted. Thus, analysis of the patient’s growth curve and Tanner stage; a radiographic bone age study; and gonadotropin measurement may be indicated.
To explain bone age, as children develop, their bones change in size and shape. These changes can be seen radiographically and can be correlated with chronologic age. Thus, the radiographic “bone age” is the average age at which children in general reach a particular stage of bone maturation. Girls with early estrogen excess from precocious puberty show growth-rate acceleration, rapid bone age advancement, early cessation of growth, and eventual short stature because of this early cessation. Bone age can be determined at many skeletal sites, and the hand and wrist are the most commonly selected.
Premature thelarche is suggested if the bone age is synchronous and thus falls within 2 standard deviations of chronologic age. However, if the bone age is advanced by 2 or more years, puberty has begun and evaluation of precocious puberty is indicated. In those with isolated premature thelarche, serum estradiol levels may be slightly elevated, and this is seen more commonly in those who were very low-birthweight infants (Klein, 1999; Nelson, 1983). In addition, serum gonadotropin levels are in the prepubertal range. In most cases, premature breast development regresses or stabilizes, and treatment consists of reassurance with careful surveillance for other signs of precocious puberty.
Growth during early breast development in girls aged 13 to 14 years may be asymmetric. The etiology is not known. However, in some cases, sports injury or surgical trauma during early breast development may lead to asymmetry (Goyal, 2003; Jansen, 2002). Examination seeks to exclude a breast mass such as a fibroadenoma or cyst. If no mass is identified, then yearly breast examinations determine the extent and persistence of asymmetry. In most cases, asymmetry will resolve by the completion of breast maturity (Templeman, 2000). Therefore, a decision toward surgical intervention is not made until full breast growth is attained. Until that time, adolescents may be fitted with padded bras or even prosthetic inserts to ensure symmetry when fully clothed.
Extremely large breasts without concurrent large breast masses can rarely develop in adolescence. Such breast hypertrophy can incite back pain, shoulder discomfort from bra-strap pressure, kyphosis, and psychologic distress. These young women will often seek reduction mammoplasty, but surgery is delayed until breast growth is completed. This is determined by serial breast measurements and is typically between the ages of 15 and 18 years.
Tuberous breasts are another growth variant (Fig. 14-10). With normal development, growth on the breast’s ventral surface projects the areola forward, and circumferential peripheral growth enlarges the breast base. In some adolescents, the fascia is densely adhered to the underlying muscle and prohibits peripheral breast growth. Only forward breast growth is permitted, and tuberous breasts form. This appearance can also follow exogenous hormone replacement that may be prescribed to girls with a lack of breast development from genetic, metabolic, or endocrine conditions. In these conditions, to avoid tuberous development, hormone replacement is initiated at small dosages and gradually increased over time. For example, transdermal estrogen (estradiol patch), 0.025 mg, may be applied twice a week for 6 months, followed by incremental dose increases every 6 months, through doses 0.05 mg and 0.075 mg, to finally reach 0.1 mg twice a week. Medroxyprogesterone acetate (Provera), 10 mg, is given orally each day for 12 days of the month to prompt withdrawal periods. Once estrogen patch dosing has reached 0.1 mg daily, the patient may alternatively be placed on a low-dose oral contraceptive pill instead.
Comparison of normal and tuberous breast development. (Modified with permission from Grolleau JL, Lanfrey E, Lavigne B, et al: Breast base anomalies: treatment strategy for tuberous breasts, minor deformities, and asymmetry, Plast Reconstruct Surg 1999 Dec;104(7):2040–2048.)
Absent Breast Development
Congenital absence of breast glandular tissue, termed amastia, is rare. More commonly, a lack of breast development results from low estrogen levels caused by constitutionally delayed puberty, chronic disease, Poland syndrome, radiation or chemotherapy, genetic disorders such as gonadal dysgenesis, or extremes of physical activity. Treatment is based on the etiology. For example, once a competitive athlete completes her career, breast development may begin spontaneously without hormonal treatment. In contrast, to prompt breast development and prevent osteoporosis, patients with gonadal dysgenesis will require some form of hormonal replacement, such as that described in the preceding section.
Breast lump complaints in an adolescent often reflect fibrocystic changes. These are characterized by patchy or diffuse, bandlike thickenings. For discrete breast masses, sonography is selected to distinguish cystic from solid mass and to define cyst qualities (Garcia, 2000). In contrast, mammography has a limited role. Its limited sensitivity and specificity in young developing dense breast tissue yields high rates of false-negative results (Williams, 1986).
Actual breast cysts are found on occasion and will usually resolve spontaneously over a few weeks to months. If a cyst is large, persistent, or symptomatic, a fine-needle aspiration may be performed using local analgesia in an office setting.
Similarly, most breast masses in children and adolescents are benign and may include normal but asymmetric breast bud development, fibroadenoma, fibrocyst, lymph node, or abscess. The most common breast mass identified in adolescence is a fibroadenoma, which accounts for 68 to 94 percent of all masses (Daniel, 1968; Goldstein, 1982). Fortunately, breast cancer in pediatric populations is rare, and cancer complicated less than 1 percent of breast masses identified in this group (Gutierrez, 2008; Neinstein, 1994). Primary breast cancer may develop more frequently in pediatric patients with a history of prior radiation, especially treatment directed to the chest wall. Additionally, metastatic disease is a consideration in those with cancer.
Treatment of breast masses includes observation, needle biopsy, and surgical excision. Observation may be appropriate for small asymptomatic lesions considered to be fibroadenomas. Masses that are symptomatic, large, or enlarging are preferably excised, and techniques mirror those in the adult (Chap. 12). For any mass not surgically excised, clinical surveillance is recommended to ensure mass stability.
Mastitis is rare in the pediatric population. Its incidence displays a bimodal distribution that peaks in the neonatal period and in children older than 10 years. The etiology in these cases is unclear, but the association with breast enlargement during these two periods has been implicated. Staphylococcus aureus is the most common isolate, and abscess develops more commonly than in the adult (Faden, 2005; Montague, 2013; Stricker, 2006). In adolescents, infections may be associated with lactation and pregnancy, trauma from sexual foreplay, shaving periareolar hair, and nipple piercing (Templeman, 2000; Tweeten, 1998). Infections are treated with antibiotics and occasional drainage if an abscess has formed.