increased in boys who are obese, compared with those who are not obese Rarely, a few conditions can be mistaken for physiologic gynecomastia, such as lipomastia, a round adipose tissue mass, or neoplasm If there is any concern for these entities or systemic diseases, then the patient should be urgently referred to an endocrinologist Overall, gynecomastia is best managed by referral to the primary care physician for continued follow-up Physiologic Mastalgia During the first trimester of pregnancy, some teenage girls may complain of breast fullness, though nongravid patients may experience breast pain as well, likely related to the hormonal milieu of the breast throughout the menstrual cycle Mastalgia is often described as a bilateral, poorly localized, dull, achy pain that radiates to the axillae The pain is often worse with activity and relieved with the onset of menses In general, there are no abnormal physical findings, except tender, nodular breasts Most patients will improve with reassurance, analgesics such as nonsteroidal anti-inflammatory medications, warm compresses, and breast support If the pain is refractory to these measures, other suggested therapies include caffeine avoidance, salt restriction, and diuretics Danazol, a synthetic androgen, is reserved for severe, debilitating pain EVALUATION AND DECISION History and Physical Examination Initial evaluation of a breast lesion begins with a careful history and physical examination ( Table 16.4 ) The two most common categories of breast lesions presenting in children are infections and structural or mass lesions In the absence of infection, evaluation of mass lesions requires a detailed menstrual history and a chronology of the development of secondary sexual characteristics Features of intracranial masses, including headaches or visual changes, should be assessed Pregnant or lactating patients may also present to a pediatric ED These patients should be queried regarding breastfeeding or breastfeeding attempts, as well as about general symptoms related to changes in the breast tissue Medications may have an effect on the growth of certain breast lesions and may also affect hormonal pathways, leading to abnormal breast secretions ( Table 16.1 ) Few breast disorders may have a familial pattern; however, a careful family history can be helpful A comprehensive physical examination should be performed on any pediatric patient who complains of a breast mass or lesion Premature appearance of