Neonatal giant mastauxe: a case report

Abstract

Introduction and importance: Giant mastauxe is an uncomplicated physiological enlargement of the breasts in newborns, characterized by a breast bud diameter greater than 3 cm. While most newborns have some degree of breast enlargement, giant mastauxe is rare, which may be unnecessarily intervened upon. Case presentation: A 13-day-term male neonate presented with bilateral breast enlargement and milky nipple discharge, which worsened upon breast massage. The mother had an uneventful pregnancy, and neither the mother nor the baby had a history of drug intake. The examination revealed soft, non-tender, non-erythematous bilateral breast swellings measuring 3.6×3.8 cm on the right side and 3.2×3.4 cm on the left side. Ultrasonography confirmed their hypoechoic nature with minimum vascularization. The white blood cell count, C-reactive protein levels, and culture of nipple discharge yielded normal results. The baby was discharged, and upon follow-up after 2 weeks, it was observed that breast swellings had spontaneously reduced in size. Discussion: Neonatal breast enlargement can occur as a result of either the transplacental transfer of maternal estrogens or declining levels of estrogens toward the end of pregnancy, leading to hyperprolactinemia. However, the exact reasons behind the occurrence of giant mastauxe in some newborns remain incompletely understood. It may be due to increased sensitivity of the breast tissue to estrogens. Conclusion: Proper clinical examination, along with the use of ultrasonography and/or laboratory investigations if required, is essential to differentiate giant mastauxe from neonatal mastitis or breast abscess. Treatment primarily involves observation and providing reassurance to parents.