Chronic encapsulated seroma is a challenging complication after breast cancer surgery, and evidence guiding its optimal management is limited. Surgical excision (capsulectomy) has been proposed as a treatment option, although data on its effectiveness and associated morbidity remain scarce.

We reviewed follow-up data from 6812 breast cancer surgeries performed at a single university hospital and identified patients who underwent capsulectomy for chronic encapsulated seroma. Risk factors and long-term outcomes were analyzed.

Chronic seroma requiring capsulectomy occurred in 1.7% (47/2736) of patients after mastectomy and in none of the patients undergoing breast-conserving surgery without axillary lymph node dissection (0/3083). Obesity was a major risk factor: 4.4% of patients with a BMI >30 kg/m2 who underwent mastectomy required seroma capsulectomy compared with 0.9% of those with normal BMI.

Following seroma capsulectomy, 68% of patients had persistent seroma beyond three months, 46% developed surgical site infection, and 48% required reoperation. Uneventful healing with complete resolution of seroma within three months from seroma capsulectomy was observed in seven patients (14%).

Chronic encapsulated seroma appears to occur predominantly in obese patients after mastectomy. Seroma capsulectomy is associated with considerable morbidity and relatively low rates of resolution. These findings should be considered when evaluating the role of surgery in clinical practice.