Amastia

Amastia is a rare condition defined by the complete absence of breast tissue (mammary glands). It is usually congenital and can affect one breast (unilateral) or both (bilateral). In some cases the nipple-areola complex is present; in others it may be absent. Congenital amastia can occur as an isolated finding or in association with chest wall or musculoskeletal anomalies and may be part of broader congenital syndromes. The prevailing view is that amastia results from failure of normal development of the embryonic mammary ridge (the milk line) during early gestation.

Diagnosis is typically clinical, with the absence of breast tissue evident on examination. Imaging such as ultrasound or MRI may be used to exclude residual glandular tissue and to assess chest wall structures. Evaluation for other congenital anomalies or syndromic associations is common, particularly if amastia is bilateral or accompanied by other findings.

Management is individualized and depends on anatomy, age, and patient preferences. There is no spontaneous restoration of tissue. Cosmetic and reconstructive options include prosthetic breast forms for symmetry, and surgical reconstruction using implants or autologous tissue. Reconstruction of the nipple-areola complex can be considered for aesthetic reasons. Timing often aligns with puberty or adulthood and typically involves a multidisciplinary team (plastic surgery, pediatrics, psychology, and, when relevant, genetics).

Prognosis varies with the presence or absence of associated anomalies. Isolated amastia without other health concerns generally has a favorable prognosis aside from cosmetic and psychosocial aspects, whereas syndromic cases require broader clinical management.