How to Manage Pleural Effusion After Breast Cancer Surgery

Postoperative pleural effusion is a recognized complication following breast cancer surgery, particularly after procedures that involve extensive lymph node dissection or reconstruction. It occurs when excess fluid accumulates in the pleural space—the potential cavity between the visceral and parietal pleura—and may manifest as dyspnea, chest discomfort, or diminished breath sounds on physical examination.

The underlying mechanisms often relate to surgical disruption of lymphatic drainage pathways, especially when axillary or internal mammary lymph nodes are removed or irradiated. Other contributing factors include postoperative inflammation, hypoalbuminemia, or, less commonly, malignant involvement of the pleura—though malignancy must be ruled out, particularly in patients with known advanced disease or atypical imaging findings.

Initial evaluation should include chest radiography and, if clinically indicated, thoracic ultrasound or contrast-enhanced CT to confirm the presence, volume, and characteristics of the effusion. Diagnostic thoracentesis is recommended for new or symptomatic effusions to assess fluid composition—including cell count, protein, lactate dehydrogenase (LDH), glucose, and cytology—to differentiate between transudative, exudative, or malignant causes.

Management depends on symptom severity and etiology. Asymptomatic, small effusions typically resolve spontaneously and warrant only observation with serial clinical assessment. For moderate-to-large or symptomatic effusions, therapeutic thoracentesis provides immediate relief and diagnostic insight. In recurrent cases, referral to interventional pulmonology or thoracic surgery may be warranted for options such as pleurodesis or indwelling pleural catheter placement.

Close multidisciplinary coordination—including oncology, surgery, radiology, and pulmonary medicine—is essential to ensure timely diagnosis, appropriate intervention, and integration with ongoing cancer treatment plans. Patients should be counseled about signs of worsening respiratory status and advised to seek urgent evaluation for acute dyspnea, fever, or hemoptysis.