Idiopathic Recurrent Unilateral Pneumomastia: Diagnostic Challenges and Therapeutic Considerations With a Rare Case of Mammary Emphysema

Pneumomastia is a rare condition characterized by air within the breast tissue. It is typically caused by trauma, iatrogenic factors, or infections. We report a 22-year-old female patient with a 20-day history of progressive, painless unilateral left breast swelling and subcutaneous emphysema following a prior spontaneously resolved episode in the contralateral breast. Imaging revealed extensive extrapulmonary air within the left breast with subcutaneous emphysema. After exclusion of life-threatening causes, including pneumothorax and esophageal perforation, ultrasound-guided needle aspiration was performed, providing symptomatic relief but complicated by post-procedural infective mastitis. While most cases resolve spontaneously, invasive interventions should be guided by symptom severity. At the 12-month follow-up, the patient remained asymptomatic with no recurrence. A review of the literature indicates that idiopathic recurrent pneumomastia is an exceptionally uncommon presentation with scarce documented cases. This case highlights diagnostic challenges and outlines management strategies in idiopathic recurrent pneumomastia.