Abrupt Aggravation of Encapsulated Seroma after Breast Reconstruction with Extended Latissimus Dorsi Muscle Flap

A 57-year-old woman underwent salvage nipple-preserving mastectomy with immediate breast reconstruction using extended latissimus dorsi muscle flap for her in-breast recurrence. The patient had been well with a presumed encapsulated seroma in her back for 8 years and 3 months but suddenly developed a protrusion of the persistent seroma. The patient requested us to improve the cosmetic deterioration of the visible large protrusion. In the operation, the operative target was converted from the newly protruded portion to the whole persistent seroma due to the leakage of presumed contaminated fluid. The posterior wall of the long-lasting seroma sticked rigidly to the ribs, forcing us not to resect the whole capsule but to resect the anterior and lateral walls with scraping the posterior wall with a curet. Pathological study showed a dense fibrous capsule, amorphous eosinophilic material, cholesterin crystals, and massive histiocyte infiltration. Postoperative course was uneventful, but wound healing was not observed over 3 weeks after operation. Minocycline 100 mg diluted in 20 mL saline was injected into the seroma cavity after full aspiration of the seroma fluid, causing immediate irritable sensation around the seroma cavity and complete disappearance of the seroma cavity in 3 weeks after the minocycline injection. Pathogenesis of this extremely rare complication remains uncertain, but long-lasting seroma formation should be avoided not to cause this type of late-phase complication. Minocycline injection into the seroma cavity is a feasible method to accelerate the wound healing.