SAT-233 Neonatal Giant Mastauxe: A case report

Abstract Disclosure: A. Riaz: None. R. Haider: None. F. Naseer: None. S. Fatima: None. A. Khan: None. M. Mal: None. A. Qadeer: None. INTRODUCTION: Giant mastauxe is a rare neonatal condition characterized by excessive breast enlargement, with a breast bud diameter exceeding 3 cm. It is an exaggerated form of common neonatal breast enlargement (1 to 2 cm) that typically resolves within six months. This condition results from maternal estrogen withdrawal, which triggers prolactin release and breast tissue proliferation. Its pronounced presentation raises parental concern and requires clinical evaluation to exclude pathological causes. Very few reports exist in literature on it. Here we report a rare case of giant mastauxe, highlighting its presentation and management. CASE PRESENTATION: A 1-month-20-day-old male infant came with bilateral breast enlargement and milky discharge since birth. There was no history of trauma or redness. He was born at 39 weeks via vaginal delivery, weighing 3100g, with APGAR scores of 8 and 9 at 1 and 5 minutes, respectively. Mother had no history of antenatal infections or drug intake, except for iron, calcium, and folic acid supplements during antenatal visits.On examination, the respiratory rate was 54 breaths/min, heart rate 140 beats/min, temperature 98.5°F, and oxygen saturation 99%. Bilateral, non-tender, non-erythematous breast swelling with soft consistency and milky discharge was noted (right: 5.1×3.2 cm; left: 3.8×3.0 cm), with retracted nipples and no skin changes.Laboratory tests showed normal leukocytes and CRP. Ultrasonography revealed enlarged breasts with dilated ducts/cysts. Diagnosed as Giant mastauxe, malignancy and inflammation were ruled out. Treatment included Miconazole gel, Miconazole nitrate, Hydrocortisone cream, Iron polymaltose complex, Vitamin B complex, Vitamin C, and Lysine.After 3 weeks, follow-up showed reduced breast size with retracted nipples and no infection. DISCUSSION: Giant Mastauxe is breast bud enlargement more than 3 cm. Postnatally, falling maternal estrogen triggers prolactin secretion in the newborn’s pituitary, leading to breast stimulation and milk secretion in 5-20% of infants. The breast's engorgement correlates with plasma prolactin, implying the infant’s prolactin drives the response. The cause of exaggerated hormonal response in neonatal mastauxe is unclear but may involve heightened sensitivity to estrogen or prolactin. increasing the risk of malignancy later. Ultrasound typically shows hypoechoic tissue for diagnosis. The condition resolves on its own, and requires simple follow-up every two months. Presentation: Saturday, July 12, 2025