27.1 Introduction

Breast asymmetry is exceedingly common during adolescence. Thelarche is marked by glandular proliferation of varying rates and may result in uneven-appearing breasts early in development. Pubertal breast asymmetry typically improves or completely resolves as breast growth slows during late adolescence. Mild breast differences, however, may persist into adulthood and is a normal finding on examination. Breast asymmetry is not a formal diagnosis, but a catch-all term encompassing a spectrum of normal and abnormal breast differences of various etiologies (Fig. 27‑1; Box 27.1).

The burden of adolescent breast asymmetry is primarily psychological. Mild to severe breast asymmetry can negatively impact an adolescent’s quality of life, psychosocial well-being, and self-esteem. Patients may report difficulty finding bras that properly fit each breast, embarrassment or teasing among peers, and reluctance to wear fitted clothing and swimsuits that highlight breast irregularities.

Nonsurgical management aims to immediately improve cosmesis and self-esteem through the use of prosthetic bra inserts and custom bras. Surgery may be warranted in cases of distressing or abnormal asymmetry that persists into late adolescence or early adulthood. The type of surgical intervention is dictated by the individual patient’s breast differences and expectations. The plastic surgeon may employ a combination of breast augmentation, mastopexy, and reduction mammaplasty to achieve symmetry and meet the individual goals of the patient.

27.2 Diagnosis

Breast asymmetry is not a formal diagnosis, but rather an umbrella term describing normal and abnormal differences in breast size, shape, or position of idiopathic, congenital, or acquired origin. Presentation and degree of severity can vary widely; however, most adolescents with breast asymmetry will exhibit normally developed breasts of unequal sizes, ranging from less than one cup size difference between breasts to that of four or more cup sizes. Asymmetry is common, and an estimated 90% of all women will experience some degree of breast asymmetry over their lifetime. Most adolescent cases are idiopathic and the byproduct of normal glandular proliferation during breast development. Onset of pubertal asymmetry is common at thelarche (Tanner stage 2) and improves over the course of breast maturation.

A variety of hyperplastic and hypoplastic breast conditions may yield asymmetries in volume, shape, and position. Unilateral macromastia or asymmetric bilateral macromastia will result in one breast that is considerably hypertrophic and ptotic relative to the contralateral breast. These patients may present with musculoskeletal pain, bra strap grooving, breast striae, and inframammary fold intertrigo. Formal “diagnosis” of unilateral or asymmetric macromastia can be supported using the Schnur Sliding Scale. Many insurers utilize this scale, which uses calculated body surface area to determine the breast resection mass necessary for a reduction mammaplasty to be considered medically indicated.

Breast asymmetry secondary to a hypoplastic breast condition is less common and presents with varying degrees of unilateral or bilateral breast insufficiency. Breast hypoplasia and amazia are defined, respectively, by an insufficiency or complete absence of breast tissue with intact pectoralis major muscle and nipple areolar complex (NAC). Amastia, however, is an extremely rare congenital anomaly marked by the absence of both the breast gland and the NAC. Tuberous breast deformity is a developmental anomaly resulting in a constricted breast, a high inframammary fold, and pseudo-herniation of the breast gland through the areola (Fig. 27‑2). Ptosis, breast hypoplasia, and skin insufficiency typically accompany moderate to severe tuberous breast deformity. Poland syndrome is a rare congenital chest anomaly affecting both males and females. Patients will present with partial or complete unilateral absence of the pectoralis major muscle, and commonly ipsilateral upper extremity anomalies. Females may also exhibit bilateral or unilateral breast hypoplasia or amazia along with a superiorly displaced and hypoplastic NAC. The majority of patients with Poland syndrome are diagnosed at birth, although extremely subtle cases may not be diagnosed until adolescence.

Adolescents may also present with acquired breast asymmetry secondary to benign masses (e.g., fibroadenoma, hemangioma, and vascular malformation), prior breast surgery, or trauma to the breast bud or gland. Presence of fibroadenoma should be ruled out in patients presenting with breast pain or tenderness.